diff --git a/include/bluetooth/mesh/access.h b/include/bluetooth/mesh/access.h
index d46a59cd255..fd7c7a4abe8 100644
--- a/include/bluetooth/mesh/access.h
+++ b/include/bluetooth/mesh/access.h
@@ -175,10 +175,12 @@ struct bt_mesh_model_op {
 	 *  @param ctx   Message context for the message.
 	 *  @param buf   Message buffer containing the message payload, not
 	 *               including the opcode.
+	 *
+	 *  @return Zero on success or (negative) error code otherwise.
 	 */
-	void (*const func)(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf);
+	int (*const func)(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf);
 };
 
 #define BT_MESH_MODEL_OP_1(b0) (b0)
diff --git a/subsys/bluetooth/mesh/access.c b/subsys/bluetooth/mesh/access.c
index 1453820c114..f71292d06d1 100644
--- a/subsys/bluetooth/mesh/access.c
+++ b/subsys/bluetooth/mesh/access.c
@@ -670,7 +670,7 @@ void bt_mesh_model_recv(struct bt_mesh_net_rx *rx, struct net_buf_simple *buf)
 		 * receive the message.
 		 */
 		net_buf_simple_save(buf, &state);
-		op->func(model, &rx->ctx, buf);
+		(void)op->func(model, &rx->ctx, buf);
 		net_buf_simple_restore(buf, &state);
 	}
 }
diff --git a/subsys/bluetooth/mesh/cfg_cli.c b/subsys/bluetooth/mesh/cfg_cli.c
index bac5aedd69a..3a0b9db74e1 100644
--- a/subsys/bluetooth/mesh/cfg_cli.c
+++ b/subsys/bluetooth/mesh/cfg_cli.c
@@ -38,9 +38,9 @@ static int32_t msg_timeout;
 
 static struct bt_mesh_cfg_cli *cli;
 
-static void comp_data_status(struct bt_mesh_model *model,
-			     struct bt_mesh_msg_ctx *ctx,
-			     struct net_buf_simple *buf)
+static int comp_data_status(struct bt_mesh_model *model,
+			    struct bt_mesh_msg_ctx *ctx,
+			    struct net_buf_simple *buf)
 {
 	struct comp_data *param;
 	size_t to_copy;
@@ -51,7 +51,7 @@ static void comp_data_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_DEV_COMP_DATA_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	if (param->page) {
@@ -62,12 +62,14 @@ static void comp_data_status(struct bt_mesh_model *model,
 	net_buf_simple_add_mem(param->comp, buf->data, to_copy);
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
-static void state_status_u8(struct bt_mesh_model *model,
-			    struct bt_mesh_msg_ctx *ctx,
-			    struct net_buf_simple *buf,
-			    uint32_t expect_status)
+static int state_status_u8(struct bt_mesh_model *model,
+			   struct bt_mesh_msg_ctx *ctx,
+			   struct net_buf_simple *buf,
+			   uint32_t expect_status)
 {
 	uint8_t *status;
 
@@ -77,40 +79,42 @@ static void state_status_u8(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, expect_status, ctx->addr,
 				       (void **)&status)) {
-		return;
+		return -ENOENT;
 	}
 
 	*status = net_buf_simple_pull_u8(buf);
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
-static void beacon_status(struct bt_mesh_model *model,
-			  struct bt_mesh_msg_ctx *ctx,
-			  struct net_buf_simple *buf)
+static int beacon_status(struct bt_mesh_model *model,
+			 struct bt_mesh_msg_ctx *ctx,
+			 struct net_buf_simple *buf)
 {
-	state_status_u8(model, ctx, buf, OP_BEACON_STATUS);
+	return state_status_u8(model, ctx, buf, OP_BEACON_STATUS);
 }
 
-static void ttl_status(struct bt_mesh_model *model,
-			  struct bt_mesh_msg_ctx *ctx,
-			  struct net_buf_simple *buf)
+static int ttl_status(struct bt_mesh_model *model,
+		      struct bt_mesh_msg_ctx *ctx,
+		      struct net_buf_simple *buf)
 {
-	state_status_u8(model, ctx, buf, OP_DEFAULT_TTL_STATUS);
+	return state_status_u8(model, ctx, buf, OP_DEFAULT_TTL_STATUS);
 }
 
-static void friend_status(struct bt_mesh_model *model,
-			  struct bt_mesh_msg_ctx *ctx,
-			  struct net_buf_simple *buf)
+static int friend_status(struct bt_mesh_model *model,
+			 struct bt_mesh_msg_ctx *ctx,
+			 struct net_buf_simple *buf)
 {
-	state_status_u8(model, ctx, buf, OP_FRIEND_STATUS);
+	return state_status_u8(model, ctx, buf, OP_FRIEND_STATUS);
 }
 
-static void gatt_proxy_status(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int gatt_proxy_status(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
-	state_status_u8(model, ctx, buf, OP_GATT_PROXY_STATUS);
+	return state_status_u8(model, ctx, buf, OP_GATT_PROXY_STATUS);
 }
 
 struct relay_param {
@@ -118,9 +122,9 @@ struct relay_param {
 	uint8_t *transmit;
 };
 
-static void relay_status(struct bt_mesh_model *model,
-			 struct bt_mesh_msg_ctx *ctx,
-			 struct net_buf_simple *buf)
+static int relay_status(struct bt_mesh_model *model,
+			struct bt_mesh_msg_ctx *ctx,
+			struct net_buf_simple *buf)
 {
 	struct relay_param *param;
 
@@ -130,18 +134,20 @@ static void relay_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_RELAY_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	*param->status = net_buf_simple_pull_u8(buf);
 	*param->transmit = net_buf_simple_pull_u8(buf);
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
-static void net_transmit_status(struct bt_mesh_model *model,
-				struct bt_mesh_msg_ctx *ctx,
-				struct net_buf_simple *buf)
+static int net_transmit_status(struct bt_mesh_model *model,
+			       struct bt_mesh_msg_ctx *ctx,
+			       struct net_buf_simple *buf)
 {
 	uint8_t *status;
 
@@ -151,12 +157,14 @@ static void net_transmit_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_NET_TRANSMIT_STATUS, ctx->addr,
 				       (void **)&status)) {
-		return;
+		return -ENOENT;
 	}
 
 	*status = net_buf_simple_pull_u8(buf);
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 struct net_key_param {
@@ -164,9 +172,9 @@ struct net_key_param {
 	uint16_t net_idx;
 };
 
-static void net_key_status(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int net_key_status(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	struct net_key_param *param;
 	uint16_t net_idx;
@@ -178,7 +186,7 @@ static void net_key_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_NET_KEY_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	status = net_buf_simple_pull_u8(buf);
@@ -186,7 +194,7 @@ static void net_key_status(struct bt_mesh_model *model,
 
 	if (param->net_idx != net_idx) {
 		BT_WARN("Net Key Status key index does not match");
-		return;
+		return -ENOENT;
 	}
 
 	if (param->status) {
@@ -194,6 +202,8 @@ static void net_key_status(struct bt_mesh_model *model,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 struct net_key_list_param {
@@ -201,9 +211,9 @@ struct net_key_list_param {
 	size_t *key_cnt;
 };
 
-static void net_key_list(struct bt_mesh_model *model,
-			 struct bt_mesh_msg_ctx *ctx,
-			 struct net_buf_simple *buf)
+static int net_key_list(struct bt_mesh_model *model,
+			struct bt_mesh_msg_ctx *ctx,
+			struct net_buf_simple *buf)
 {
 	struct net_key_list_param *param;
 	int i;
@@ -214,7 +224,7 @@ static void net_key_list(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_NET_KEY_LIST, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	for (i = 0; i < *param->key_cnt && buf->len >= 3; i += 2) {
@@ -228,10 +238,13 @@ static void net_key_list(struct bt_mesh_model *model,
 	*param->key_cnt = i;
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
-static void node_reset_status(struct bt_mesh_model *model,
-		struct bt_mesh_msg_ctx *ctx, struct net_buf_simple *buf)
+static int node_reset_status(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	bool *param = NULL;
 	BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x",
@@ -239,13 +252,15 @@ static void node_reset_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_NODE_RESET_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	if (param) {
 		*param = true;
 	}
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 struct app_key_param {
@@ -254,9 +269,9 @@ struct app_key_param {
 	uint16_t app_idx;
 };
 
-static void app_key_status(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int app_key_status(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	struct app_key_param *param;
 	uint16_t net_idx, app_idx;
@@ -268,7 +283,7 @@ static void app_key_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_APP_KEY_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	status = net_buf_simple_pull_u8(buf);
@@ -276,7 +291,7 @@ static void app_key_status(struct bt_mesh_model *model,
 
 	if (param->net_idx != net_idx || param->app_idx != app_idx) {
 		BT_WARN("App Key Status key indices did not match");
-		return;
+		return -ENOENT;
 	}
 
 	if (param->status) {
@@ -284,6 +299,8 @@ static void app_key_status(struct bt_mesh_model *model,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 struct app_key_list_param {
@@ -293,9 +310,9 @@ struct app_key_list_param {
 	size_t *key_cnt;
 };
 
-static void app_key_list(struct bt_mesh_model *model,
-			 struct bt_mesh_msg_ctx *ctx,
-			 struct net_buf_simple *buf)
+static int app_key_list(struct bt_mesh_model *model,
+			struct bt_mesh_msg_ctx *ctx,
+			struct net_buf_simple *buf)
 {
 	struct app_key_list_param *param;
 	uint16_t net_idx;
@@ -308,7 +325,7 @@ static void app_key_list(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_APP_KEY_LIST, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	status = net_buf_simple_pull_u8(buf);
@@ -316,7 +333,7 @@ static void app_key_list(struct bt_mesh_model *model,
 
 	if (param->net_idx != net_idx) {
 		BT_WARN("App Key List Net Key index did not match");
-		return;
+		return -ENOENT;
 	}
 
 	for (i = 0; i < *param->key_cnt && buf->len >= 3; i += 2) {
@@ -333,6 +350,8 @@ static void app_key_list(struct bt_mesh_model *model,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 struct mod_app_param {
@@ -343,9 +362,9 @@ struct mod_app_param {
 	uint16_t cid;
 };
 
-static void mod_app_status(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int mod_app_status(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, mod_app_idx, mod_id, cid;
 	struct mod_app_param *param;
@@ -357,7 +376,7 @@ static void mod_app_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_MOD_APP_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	status = net_buf_simple_pull_u8(buf);
@@ -376,7 +395,7 @@ static void mod_app_status(struct bt_mesh_model *model,
 	    param->mod_app_idx != mod_app_idx || param->mod_id != mod_id ||
 	    param->cid != cid) {
 		BT_WARN("Model App Status parameters did not match");
-		return;
+		return -ENOENT;
 	}
 
 	if (param->status) {
@@ -384,6 +403,8 @@ static void mod_app_status(struct bt_mesh_model *model,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 struct mod_member_list_param {
@@ -395,9 +416,9 @@ struct mod_member_list_param {
 	size_t *member_cnt;
 };
 
-static void mod_member_list_handle(struct bt_mesh_msg_ctx *ctx,
-				   struct net_buf_simple *buf, bool vnd,
-				   struct mod_member_list_param *param)
+static int mod_member_list_handle(struct bt_mesh_msg_ctx *ctx,
+				  struct net_buf_simple *buf, bool vnd,
+				  struct mod_member_list_param *param)
 {
 	uint16_t elem_addr, mod_id, cid;
 	uint8_t status;
@@ -414,12 +435,12 @@ static void mod_member_list_handle(struct bt_mesh_msg_ctx *ctx,
 	if (param->elem_addr != elem_addr || param->mod_id != mod_id ||
 	    (vnd && param->cid != cid)) {
 		BT_WARN("Model Member List parameters did not match");
-		return;
+		return -ENOENT;
 	}
 
 	if (buf->len % 2) {
 		BT_WARN("Model Member List invalid length");
-		return;
+		return -EINVAL;
 	}
 
 	for (i = 0; i < *param->member_cnt && buf->len; i++) {
@@ -432,11 +453,13 @@ static void mod_member_list_handle(struct bt_mesh_msg_ctx *ctx,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
-static void mod_app_list(struct bt_mesh_model *model,
-			 struct bt_mesh_msg_ctx *ctx,
-			 struct net_buf_simple *buf)
+static int mod_app_list(struct bt_mesh_model *model,
+			struct bt_mesh_msg_ctx *ctx,
+			struct net_buf_simple *buf)
 {
 	struct mod_member_list_param *param;
 
@@ -446,15 +469,15 @@ static void mod_app_list(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_SIG_MOD_APP_LIST, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
-	mod_member_list_handle(ctx, buf, false, param);
+	return mod_member_list_handle(ctx, buf, false, param);
 }
 
-static void mod_app_list_vnd(struct bt_mesh_model *model,
-			     struct bt_mesh_msg_ctx *ctx,
-			     struct net_buf_simple *buf)
+static int mod_app_list_vnd(struct bt_mesh_model *model,
+			    struct bt_mesh_msg_ctx *ctx,
+			    struct net_buf_simple *buf)
 {
 	struct mod_member_list_param *param;
 
@@ -464,10 +487,10 @@ static void mod_app_list_vnd(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_VND_MOD_APP_LIST, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
-	mod_member_list_handle(ctx, buf, true, param);
+	return mod_member_list_handle(ctx, buf, true, param);
 }
 
 struct mod_pub_param {
@@ -478,7 +501,7 @@ struct mod_pub_param {
 	struct bt_mesh_cfg_mod_pub *pub;
 };
 
-static void mod_pub_status(struct bt_mesh_model *model,
+static int mod_pub_status(struct bt_mesh_model *model,
 			   struct bt_mesh_msg_ctx *ctx,
 			   struct net_buf_simple *buf)
 {
@@ -492,13 +515,13 @@ static void mod_pub_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_MOD_PUB_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	if (param->cid != CID_NVAL) {
 		if (buf->len < 14) {
 			BT_WARN("Unexpected Mod Pub Status with SIG Model");
-			return;
+			return -ENOENT;
 		}
 
 		cid = sys_get_le16(&buf->data[10]);
@@ -506,7 +529,7 @@ static void mod_pub_status(struct bt_mesh_model *model,
 	} else {
 		if (buf->len > 12) {
 			BT_WARN("Unexpected Mod Pub Status with Vendor Model");
-			return;
+			return -ENOENT;
 		}
 
 		cid = CID_NVAL;
@@ -515,7 +538,7 @@ static void mod_pub_status(struct bt_mesh_model *model,
 
 	if (mod_id != param->mod_id || cid != param->cid) {
 		BT_WARN("Mod Pub Model ID or Company ID mismatch");
-		return;
+		return -ENOENT;
 	}
 
 	status = net_buf_simple_pull_u8(buf);
@@ -524,7 +547,7 @@ static void mod_pub_status(struct bt_mesh_model *model,
 	if (elem_addr != param->elem_addr) {
 		BT_WARN("Model Pub Status for unexpected element (0x%04x)",
 			elem_addr);
-		return;
+		return -ENOENT;
 	}
 
 	if (param->status) {
@@ -542,6 +565,8 @@ static void mod_pub_status(struct bt_mesh_model *model,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 struct mod_sub_param {
@@ -553,9 +578,9 @@ struct mod_sub_param {
 	uint16_t cid;
 };
 
-static void mod_sub_status(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int mod_sub_status(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, sub_addr, mod_id, cid;
 	struct mod_sub_param *param;
@@ -567,7 +592,7 @@ static void mod_sub_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_MOD_SUB_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	status = net_buf_simple_pull_u8(buf);
@@ -586,7 +611,7 @@ static void mod_sub_status(struct bt_mesh_model *model,
 	    (param->expect_sub && *param->expect_sub != sub_addr) ||
 	    param->cid != cid) {
 		BT_WARN("Model Subscription Status parameters did not match");
-		return;
+		return -ENOENT;
 	}
 
 	if (param->sub_addr) {
@@ -598,11 +623,13 @@ static void mod_sub_status(struct bt_mesh_model *model,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
-static void mod_sub_list(struct bt_mesh_model *model,
-			 struct bt_mesh_msg_ctx *ctx,
-			 struct net_buf_simple *buf)
+static int mod_sub_list(struct bt_mesh_model *model,
+			struct bt_mesh_msg_ctx *ctx,
+			struct net_buf_simple *buf)
 {
 	struct mod_member_list_param *param;
 
@@ -612,15 +639,15 @@ static void mod_sub_list(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_MOD_SUB_LIST, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
-	mod_member_list_handle(ctx, buf, false, param);
+	return mod_member_list_handle(ctx, buf, false, param);
 }
 
-static void mod_sub_list_vnd(struct bt_mesh_model *model,
-			     struct bt_mesh_msg_ctx *ctx,
-			     struct net_buf_simple *buf)
+static int mod_sub_list_vnd(struct bt_mesh_model *model,
+			    struct bt_mesh_msg_ctx *ctx,
+			    struct net_buf_simple *buf)
 {
 	struct mod_member_list_param *param;
 
@@ -630,10 +657,10 @@ static void mod_sub_list_vnd(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_MOD_SUB_LIST_VND, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
-	mod_member_list_handle(ctx, buf, true, param);
+	return mod_member_list_handle(ctx, buf, true, param);
 }
 
 struct hb_sub_param {
@@ -641,9 +668,9 @@ struct hb_sub_param {
 	struct bt_mesh_cfg_hb_sub *sub;
 };
 
-static void hb_sub_status(struct bt_mesh_model *model,
-			  struct bt_mesh_msg_ctx *ctx,
-			  struct net_buf_simple *buf)
+static int hb_sub_status(struct bt_mesh_model *model,
+			 struct bt_mesh_msg_ctx *ctx,
+			 struct net_buf_simple *buf)
 {
 	struct hb_sub_param *param;
 
@@ -653,7 +680,7 @@ static void hb_sub_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_HEARTBEAT_SUB_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	*param->status = net_buf_simple_pull_u8(buf);
@@ -666,6 +693,8 @@ static void hb_sub_status(struct bt_mesh_model *model,
 	param->sub->max = net_buf_simple_pull_u8(buf);
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 struct hb_pub_param {
@@ -673,9 +702,9 @@ struct hb_pub_param {
 	struct bt_mesh_cfg_hb_pub *pub;
 };
 
-static void hb_pub_status(struct bt_mesh_model *model,
-			  struct bt_mesh_msg_ctx *ctx,
-			  struct net_buf_simple *buf)
+static int hb_pub_status(struct bt_mesh_model *model,
+			 struct bt_mesh_msg_ctx *ctx,
+			 struct net_buf_simple *buf)
 {
 	struct hb_pub_param *param;
 
@@ -685,7 +714,7 @@ static void hb_pub_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&cli->ack_ctx, OP_HEARTBEAT_PUB_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	*param->status = net_buf_simple_pull_u8(buf);
@@ -700,6 +729,8 @@ static void hb_pub_status(struct bt_mesh_model *model,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&cli->ack_ctx);
+
+	return 0;
 }
 
 const struct bt_mesh_model_op bt_mesh_cfg_cli_op[] = {
diff --git a/subsys/bluetooth/mesh/cfg_srv.c b/subsys/bluetooth/mesh/cfg_srv.c
index e98b5dbef8e..b468f8f0930 100644
--- a/subsys/bluetooth/mesh/cfg_srv.c
+++ b/subsys/bluetooth/mesh/cfg_srv.c
@@ -111,12 +111,13 @@ static int comp_get_page_0(struct net_buf_simple *buf)
 	return 0;
 }
 
-static void dev_comp_data_get(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int dev_comp_data_get(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	NET_BUF_SIMPLE_DEFINE(sdu, BT_MESH_TX_SDU_MAX);
 	uint8_t page;
+	int err;
 
 	BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
 	       ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
@@ -131,14 +132,17 @@ static void dev_comp_data_get(struct bt_mesh_model *model,
 	bt_mesh_model_msg_init(&sdu, OP_DEV_COMP_DATA_STATUS);
 
 	net_buf_simple_add_u8(&sdu, page);
-	if (comp_get_page_0(&sdu) < 0) {
+	err = comp_get_page_0(&sdu);
+	if (err) {
 		BT_ERR("Unable to get composition page 0");
-		return;
+		return err;
 	}
 
 	if (bt_mesh_model_send(model, ctx, &sdu, NULL, NULL)) {
 		BT_ERR("Unable to send Device Composition Status response");
 	}
+
+	return err;
 }
 
 static struct bt_mesh_model *get_model(struct bt_mesh_elem *elem,
@@ -319,10 +323,10 @@ static uint8_t mod_unbind(struct bt_mesh_model *model, uint16_t key_idx, bool st
 	return STATUS_SUCCESS;
 }
 
-static void send_app_key_status(struct bt_mesh_model *model,
-				struct bt_mesh_msg_ctx *ctx,
-				uint8_t status,
-				uint16_t app_idx, uint16_t net_idx)
+static int send_app_key_status(struct bt_mesh_model *model,
+			       struct bt_mesh_msg_ctx *ctx,
+			       uint8_t status,
+			       uint16_t app_idx, uint16_t net_idx)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_STATUS, 4);
 
@@ -333,11 +337,13 @@ static void send_app_key_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send App Key Status response");
 	}
+
+	return 0;
 }
 
-static void app_key_add(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int app_key_add(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	uint16_t key_net_idx, key_app_idx;
 	uint8_t status;
@@ -348,12 +354,12 @@ static void app_key_add(struct bt_mesh_model *model,
 
 	status = bt_mesh_app_key_add(key_app_idx, key_net_idx, buf->data);
 
-	send_app_key_status(model, ctx, status, key_app_idx, key_net_idx);
+	return send_app_key_status(model, ctx, status, key_app_idx, key_net_idx);
 }
 
-static void app_key_update(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int app_key_update(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	uint16_t key_net_idx, key_app_idx;
 	uint8_t status;
@@ -365,7 +371,7 @@ static void app_key_update(struct bt_mesh_model *model,
 	status = bt_mesh_app_key_update(key_app_idx, key_net_idx, buf->data);
 	BT_DBG("status 0x%02x", status);
 
-	send_app_key_status(model, ctx, status, key_app_idx, key_net_idx);
+	return send_app_key_status(model, ctx, status, key_app_idx, key_net_idx);
 }
 
 static void mod_app_key_del(struct bt_mesh_model *mod,
@@ -387,9 +393,9 @@ static void app_key_evt(uint16_t app_idx, uint16_t net_idx,
 
 BT_MESH_APP_KEY_CB_DEFINE(app_key_evt);
 
-static void app_key_del(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int app_key_del(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	uint16_t key_net_idx, key_app_idx;
 	uint8_t status;
@@ -400,15 +406,15 @@ static void app_key_del(struct bt_mesh_model *model,
 
 	status = bt_mesh_app_key_del(key_app_idx, key_net_idx);
 
-	send_app_key_status(model, ctx, status, key_app_idx, key_net_idx);
+	return send_app_key_status(model, ctx, status, key_app_idx, key_net_idx);
 }
 
 /* Index list length: 3 bytes for every pair and 2 bytes for an odd idx */
 #define IDX_LEN(num) (((num) / 2) * 3 + ((num) % 2) * 2)
 
-static void app_key_get(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int app_key_get(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_LIST,
 				 3 + IDX_LEN(CONFIG_BT_MESH_APP_KEY_COUNT));
@@ -421,7 +427,7 @@ static void app_key_get(struct bt_mesh_model *model,
 	get_idx = net_buf_simple_pull_le16(buf);
 	if (get_idx > 0xfff) {
 		BT_ERR("Invalid NetKeyIndex 0x%04x", get_idx);
-		return;
+		return -EINVAL;
 	}
 
 	BT_DBG("idx 0x%04x", get_idx);
@@ -458,11 +464,13 @@ send_status:
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send AppKey List");
 	}
+
+	return 0;
 }
 
-static void beacon_get(struct bt_mesh_model *model,
-		       struct bt_mesh_msg_ctx *ctx,
-		       struct net_buf_simple *buf)
+static int beacon_get(struct bt_mesh_model *model,
+		      struct bt_mesh_msg_ctx *ctx,
+		      struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_BEACON_STATUS, 1);
 
@@ -476,11 +484,13 @@ static void beacon_get(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Config Beacon Status response");
 	}
+
+	return 0;
 }
 
-static void beacon_set(struct bt_mesh_model *model,
-		       struct bt_mesh_msg_ctx *ctx,
-		       struct net_buf_simple *buf)
+static int beacon_set(struct bt_mesh_model *model,
+		      struct bt_mesh_msg_ctx *ctx,
+		      struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_BEACON_STATUS, 1);
 
@@ -490,7 +500,7 @@ static void beacon_set(struct bt_mesh_model *model,
 
 	if (buf->data[0] != 0x00 && buf->data[0] != 0x01) {
 		BT_WARN("Invalid Config Beacon value 0x%02x", buf->data[0]);
-		return;
+		return -EINVAL;
 	}
 
 	bt_mesh_beacon_set(buf->data[0]);
@@ -501,11 +511,13 @@ static void beacon_set(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Config Beacon Status response");
 	}
+
+	return 0;
 }
 
-static void default_ttl_get(struct bt_mesh_model *model,
-			    struct bt_mesh_msg_ctx *ctx,
-			    struct net_buf_simple *buf)
+static int default_ttl_get(struct bt_mesh_model *model,
+			   struct bt_mesh_msg_ctx *ctx,
+			   struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_DEFAULT_TTL_STATUS, 1);
 
@@ -519,11 +531,13 @@ static void default_ttl_get(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Default TTL Status response");
 	}
+
+	return 0;
 }
 
-static void default_ttl_set(struct bt_mesh_model *model,
-			    struct bt_mesh_msg_ctx *ctx,
-			    struct net_buf_simple *buf)
+static int default_ttl_set(struct bt_mesh_model *model,
+			   struct bt_mesh_msg_ctx *ctx,
+			   struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_DEFAULT_TTL_STATUS, 1);
 	int err;
@@ -535,7 +549,7 @@ static void default_ttl_set(struct bt_mesh_model *model,
 	err = bt_mesh_default_ttl_set(buf->data[0]);
 	if (err) {
 		BT_WARN("Prohibited Default TTL value 0x%02x", buf->data[0]);
-		return;
+		return err;
 	}
 
 	bt_mesh_model_msg_init(&msg, OP_DEFAULT_TTL_STATUS);
@@ -544,10 +558,12 @@ static void default_ttl_set(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Default TTL Status response");
 	}
+
+	return 0;
 }
 
-static void send_gatt_proxy_status(struct bt_mesh_model *model,
-				   struct bt_mesh_msg_ctx *ctx)
+static int send_gatt_proxy_status(struct bt_mesh_model *model,
+				  struct bt_mesh_msg_ctx *ctx)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_GATT_PROXY_STATUS, 1);
 
@@ -557,22 +573,24 @@ static void send_gatt_proxy_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send GATT Proxy Status");
 	}
+
+	return 0;
 }
 
-static void gatt_proxy_get(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int gatt_proxy_get(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
 	       ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
 	       bt_hex(buf->data, buf->len));
 
-	send_gatt_proxy_status(model, ctx);
+	return send_gatt_proxy_status(model, ctx);
 }
 
-static void gatt_proxy_set(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int gatt_proxy_set(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
 	       ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
@@ -580,17 +598,17 @@ static void gatt_proxy_set(struct bt_mesh_model *model,
 
 	if (buf->data[0] != 0x00 && buf->data[0] != 0x01) {
 		BT_WARN("Invalid GATT Proxy value 0x%02x", buf->data[0]);
-		return;
+		return -EINVAL;
 	}
 
 	(void)bt_mesh_gatt_proxy_set(buf->data[0]);
 
-	send_gatt_proxy_status(model, ctx);
+	return send_gatt_proxy_status(model, ctx);
 }
 
-static void net_transmit_get(struct bt_mesh_model *model,
-			     struct bt_mesh_msg_ctx *ctx,
-			     struct net_buf_simple *buf)
+static int net_transmit_get(struct bt_mesh_model *model,
+			    struct bt_mesh_msg_ctx *ctx,
+			    struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_NET_TRANSMIT_STATUS, 1);
 
@@ -604,11 +622,13 @@ static void net_transmit_get(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Config Network Transmit Status");
 	}
+
+	return 0;
 }
 
-static void net_transmit_set(struct bt_mesh_model *model,
-			     struct bt_mesh_msg_ctx *ctx,
-			     struct net_buf_simple *buf)
+static int net_transmit_set(struct bt_mesh_model *model,
+			    struct bt_mesh_msg_ctx *ctx,
+			    struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_NET_TRANSMIT_STATUS, 1);
 
@@ -628,11 +648,13 @@ static void net_transmit_set(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Network Transmit Status");
 	}
+
+	return 0;
 }
 
-static void relay_get(struct bt_mesh_model *model,
-		      struct bt_mesh_msg_ctx *ctx,
-		      struct net_buf_simple *buf)
+static int relay_get(struct bt_mesh_model *model,
+		     struct bt_mesh_msg_ctx *ctx,
+		     struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_RELAY_STATUS, 2);
 
@@ -647,11 +669,13 @@ static void relay_get(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Config Relay Status response");
 	}
+
+	return 0;
 }
 
-static void relay_set(struct bt_mesh_model *model,
-		      struct bt_mesh_msg_ctx *ctx,
-		      struct net_buf_simple *buf)
+static int relay_set(struct bt_mesh_model *model,
+		     struct bt_mesh_msg_ctx *ctx,
+		     struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_RELAY_STATUS, 2);
 
@@ -661,7 +685,7 @@ static void relay_set(struct bt_mesh_model *model,
 
 	if (buf->data[0] != 0x00 && buf->data[0] != 0x01) {
 		BT_WARN("Invalid Relay value 0x%02x", buf->data[0]);
-		return;
+		return -EINVAL;
 	}
 
 	(void)bt_mesh_relay_set(buf->data[0], buf->data[1]);
@@ -673,13 +697,15 @@ static void relay_set(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Relay Status response");
 	}
+
+	return 0;
 }
 
-static void send_mod_pub_status(struct bt_mesh_model *cfg_mod,
-				struct bt_mesh_msg_ctx *ctx,
-				uint16_t elem_addr, uint16_t pub_addr,
-				bool vnd, struct bt_mesh_model *mod,
-				uint8_t status, uint8_t *mod_id)
+static int send_mod_pub_status(struct bt_mesh_model *cfg_mod,
+			       struct bt_mesh_msg_ctx *ctx, uint16_t elem_addr,
+			       uint16_t pub_addr, bool vnd,
+			       struct bt_mesh_model *mod, uint8_t status,
+			       uint8_t *mod_id)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_PUB_STATUS, 14);
 
@@ -711,11 +737,12 @@ static void send_mod_pub_status(struct bt_mesh_model *cfg_mod,
 	if (bt_mesh_model_send(cfg_mod, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Model Publication Status");
 	}
+
+	return 0;
 }
 
-static void mod_pub_get(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int mod_pub_get(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, pub_addr = 0U;
 	struct bt_mesh_model *mod;
@@ -726,7 +753,7 @@ static void mod_pub_get(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	mod_id = buf->data;
@@ -756,13 +783,13 @@ static void mod_pub_get(struct bt_mesh_model *model,
 	status = STATUS_SUCCESS;
 
 send_status:
-	send_mod_pub_status(model, ctx, elem_addr, pub_addr, vnd, mod,
-			    status, mod_id);
+	return send_mod_pub_status(model, ctx, elem_addr, pub_addr, vnd, mod,
+				   status, mod_id);
 }
 
-static void mod_pub_set(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int mod_pub_set(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	uint8_t retransmit, status, pub_ttl, pub_period, cred_flag;
 	uint16_t elem_addr, pub_addr, pub_app_idx;
@@ -774,7 +801,7 @@ static void mod_pub_set(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	pub_addr = net_buf_simple_pull_le16(buf);
@@ -785,7 +812,7 @@ static void mod_pub_set(struct bt_mesh_model *model,
 	pub_ttl = net_buf_simple_pull_u8(buf);
 	if (pub_ttl > BT_MESH_TTL_MAX && pub_ttl != BT_MESH_TTL_DEFAULT) {
 		BT_ERR("Invalid TTL value 0x%02x", pub_ttl);
-		return;
+		return -EINVAL;
 	}
 
 	pub_period = net_buf_simple_pull_u8(buf);
@@ -818,8 +845,8 @@ static void mod_pub_set(struct bt_mesh_model *model,
 			      pub_period, retransmit, true);
 
 send_status:
-	send_mod_pub_status(model, ctx, elem_addr, pub_addr, vnd, mod,
-			    status, mod_id);
+	return send_mod_pub_status(model, ctx, elem_addr, pub_addr, vnd, mod,
+				   status, mod_id);
 }
 
 static size_t mod_sub_list_clear(struct bt_mesh_model *mod)
@@ -854,9 +881,9 @@ static size_t mod_sub_list_clear(struct bt_mesh_model *mod)
 	return clear_count;
 }
 
-static void mod_pub_va_set(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int mod_pub_va_set(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	uint8_t retransmit, status, pub_ttl, pub_period, cred_flag;
 	uint16_t elem_addr, pub_addr, pub_app_idx;
@@ -869,7 +896,7 @@ static void mod_pub_va_set(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	label_uuid = net_buf_simple_pull_mem(buf, 16);
@@ -879,7 +906,7 @@ static void mod_pub_va_set(struct bt_mesh_model *model,
 	pub_ttl = net_buf_simple_pull_u8(buf);
 	if (pub_ttl > BT_MESH_TTL_MAX && pub_ttl != BT_MESH_TTL_DEFAULT) {
 		BT_ERR("Invalid TTL value 0x%02x", pub_ttl);
-		return;
+		return -EINVAL;
 	}
 
 	pub_period = net_buf_simple_pull_u8(buf);
@@ -921,14 +948,14 @@ static void mod_pub_va_set(struct bt_mesh_model *model,
 	}
 
 send_status:
-	send_mod_pub_status(model, ctx, elem_addr, pub_addr, vnd, mod,
-			    status, mod_id);
+	return send_mod_pub_status(model, ctx, elem_addr, pub_addr, vnd, mod,
+				   status, mod_id);
 }
 
-static void send_mod_sub_status(struct bt_mesh_model *model,
-				struct bt_mesh_msg_ctx *ctx, uint8_t status,
-				uint16_t elem_addr, uint16_t sub_addr, uint8_t *mod_id,
-				bool vnd)
+static int send_mod_sub_status(struct bt_mesh_model *model,
+			       struct bt_mesh_msg_ctx *ctx, uint8_t status,
+			       uint16_t elem_addr, uint16_t sub_addr, uint8_t *mod_id,
+			       bool vnd)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_SUB_STATUS, 9);
 
@@ -950,11 +977,13 @@ static void send_mod_sub_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Model Subscription Status");
 	}
+
+	return 0;
 }
 
-static void mod_sub_add(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int mod_sub_add(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, sub_addr;
 	struct bt_mesh_model *mod;
@@ -967,7 +996,7 @@ static void mod_sub_add(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	sub_addr = net_buf_simple_pull_le16(buf);
@@ -1021,13 +1050,13 @@ static void mod_sub_add(struct bt_mesh_model *model,
 
 
 send_status:
-	send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
-			    mod_id, vnd);
+	return send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
+				   mod_id, vnd);
 }
 
-static void mod_sub_del(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int mod_sub_del(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, sub_addr;
 	struct bt_mesh_model *mod;
@@ -1040,7 +1069,7 @@ static void mod_sub_del(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	sub_addr = net_buf_simple_pull_le16(buf);
@@ -1087,8 +1116,8 @@ static void mod_sub_del(struct bt_mesh_model *model,
 	}
 
 send_status:
-	send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
-			    mod_id, vnd);
+	return send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
+				   mod_id, vnd);
 }
 
 static enum bt_mesh_walk mod_sub_clear_visitor(struct bt_mesh_model *mod,
@@ -1103,9 +1132,9 @@ static enum bt_mesh_walk mod_sub_clear_visitor(struct bt_mesh_model *mod,
 	return BT_MESH_WALK_CONTINUE;
 }
 
-static void mod_sub_overwrite(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int mod_sub_overwrite(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, sub_addr;
 	struct bt_mesh_model *mod;
@@ -1117,7 +1146,7 @@ static void mod_sub_overwrite(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	sub_addr = net_buf_simple_pull_le16(buf);
@@ -1166,13 +1195,13 @@ static void mod_sub_overwrite(struct bt_mesh_model *model,
 
 
 send_status:
-	send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
-			    mod_id, vnd);
+	return send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
+				   mod_id, vnd);
 }
 
-static void mod_sub_del_all(struct bt_mesh_model *model,
-			    struct bt_mesh_msg_ctx *ctx,
-			    struct net_buf_simple *buf)
+static int mod_sub_del_all(struct bt_mesh_model *model,
+			   struct bt_mesh_msg_ctx *ctx,
+			   struct net_buf_simple *buf)
 {
 	struct bt_mesh_model *mod;
 	struct bt_mesh_elem *elem;
@@ -1184,7 +1213,7 @@ static void mod_sub_del_all(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	BT_DBG("elem_addr 0x%04x", elem_addr);
@@ -1215,8 +1244,8 @@ static void mod_sub_del_all(struct bt_mesh_model *model,
 	status = STATUS_SUCCESS;
 
 send_status:
-	send_mod_sub_status(model, ctx, status, elem_addr,
-			    BT_MESH_ADDR_UNASSIGNED, mod_id, vnd);
+	return send_mod_sub_status(model, ctx, status, elem_addr,
+				   BT_MESH_ADDR_UNASSIGNED, mod_id, vnd);
 }
 
 struct mod_sub_list_ctx {
@@ -1256,9 +1285,9 @@ static enum bt_mesh_walk mod_sub_list_visitor(struct bt_mesh_model *mod,
 	return BT_MESH_WALK_CONTINUE;
 }
 
-static void mod_sub_get(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int mod_sub_get(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	NET_BUF_SIMPLE_DEFINE(msg, BT_MESH_TX_SDU_MAX);
 	struct mod_sub_list_ctx visit_ctx;
@@ -1269,7 +1298,7 @@ static void mod_sub_get(struct bt_mesh_model *model,
 	addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	id = net_buf_simple_pull_le16(buf);
@@ -1308,11 +1337,13 @@ send_list:
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Model Subscription List");
 	}
+
+	return 0;
 }
 
-static void mod_sub_get_vnd(struct bt_mesh_model *model,
-			    struct bt_mesh_msg_ctx *ctx,
-			    struct net_buf_simple *buf)
+static int mod_sub_get_vnd(struct bt_mesh_model *model,
+			   struct bt_mesh_msg_ctx *ctx,
+			   struct net_buf_simple *buf)
 {
 	NET_BUF_SIMPLE_DEFINE(msg, BT_MESH_TX_SDU_MAX);
 	struct mod_sub_list_ctx visit_ctx;
@@ -1323,7 +1354,7 @@ static void mod_sub_get_vnd(struct bt_mesh_model *model,
 	addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	company = net_buf_simple_pull_le16(buf);
@@ -1366,11 +1397,13 @@ send_list:
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Vendor Model Subscription List");
 	}
+
+	return 0;
 }
 
-static void mod_sub_va_add(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int mod_sub_va_add(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, sub_addr;
 	struct bt_mesh_model *mod;
@@ -1384,7 +1417,7 @@ static void mod_sub_va_add(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	label_uuid = net_buf_simple_pull_mem(buf, 16);
@@ -1441,13 +1474,13 @@ static void mod_sub_va_add(struct bt_mesh_model *model,
 	status = STATUS_SUCCESS;
 
 send_status:
-	send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
-			    mod_id, vnd);
+	return send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
+				   mod_id, vnd);
 }
 
-static void mod_sub_va_del(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int mod_sub_va_del(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, sub_addr;
 	struct bt_mesh_model *mod;
@@ -1461,7 +1494,7 @@ static void mod_sub_va_del(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	label_uuid = net_buf_simple_pull_mem(buf, 16);
@@ -1509,13 +1542,13 @@ static void mod_sub_va_del(struct bt_mesh_model *model,
 	}
 
 send_status:
-	send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
-			    mod_id, vnd);
+	return send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
+				   mod_id, vnd);
 }
 
-static void mod_sub_va_overwrite(struct bt_mesh_model *model,
-				 struct bt_mesh_msg_ctx *ctx,
-				 struct net_buf_simple *buf)
+static int mod_sub_va_overwrite(struct bt_mesh_model *model,
+				struct bt_mesh_msg_ctx *ctx,
+				struct net_buf_simple *buf)
 {
 	uint16_t elem_addr, sub_addr = BT_MESH_ADDR_UNASSIGNED;
 	struct bt_mesh_model *mod;
@@ -1528,7 +1561,7 @@ static void mod_sub_va_overwrite(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	label_uuid = net_buf_simple_pull_mem(buf, 16);
@@ -1573,13 +1606,13 @@ static void mod_sub_va_overwrite(struct bt_mesh_model *model,
 	}
 
 send_status:
-	send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
-			    mod_id, vnd);
+	return send_mod_sub_status(model, ctx, status, elem_addr, sub_addr,
+				   mod_id, vnd);
 }
 
-static void send_net_key_status(struct bt_mesh_model *model,
-				struct bt_mesh_msg_ctx *ctx,
-				uint16_t idx, uint8_t status)
+static int send_net_key_status(struct bt_mesh_model *model,
+			       struct bt_mesh_msg_ctx *ctx, uint16_t idx,
+			       uint8_t status)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_NET_KEY_STATUS, 3);
 
@@ -1591,11 +1624,12 @@ static void send_net_key_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send NetKey Status");
 	}
+
+	return 0;
 }
 
-static void net_key_add(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int net_key_add(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	uint8_t status;
 	uint16_t idx;
@@ -1603,19 +1637,19 @@ static void net_key_add(struct bt_mesh_model *model,
 	idx = net_buf_simple_pull_le16(buf);
 	if (idx > 0xfff) {
 		BT_ERR("Invalid NetKeyIndex 0x%04x", idx);
-		return;
+		return -EINVAL;
 	}
 
 	BT_DBG("idx 0x%04x", idx);
 
 	status = bt_mesh_subnet_add(idx, buf->data);
 
-	send_net_key_status(model, ctx, idx, status);
+	return send_net_key_status(model, ctx, idx, status);
 }
 
-static void net_key_update(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int net_key_update(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	uint8_t status;
 	uint16_t idx;
@@ -1623,24 +1657,24 @@ static void net_key_update(struct bt_mesh_model *model,
 	idx = net_buf_simple_pull_le16(buf);
 	if (idx > 0xfff) {
 		BT_ERR("Invalid NetKeyIndex 0x%04x", idx);
-		return;
+		return -EINVAL;
 	}
 
 	status = bt_mesh_subnet_update(idx, buf->data);
 
-	send_net_key_status(model, ctx, idx, status);
+	return send_net_key_status(model, ctx, idx, status);
 }
 
-static void net_key_del(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int net_key_del(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	uint16_t del_idx;
 
 	del_idx = net_buf_simple_pull_le16(buf);
 	if (del_idx > 0xfff) {
 		BT_ERR("Invalid NetKeyIndex 0x%04x", del_idx);
-		return;
+		return -EINVAL;
 	}
 
 	BT_DBG("idx 0x%04x", del_idx);
@@ -1649,19 +1683,18 @@ static void net_key_del(struct bt_mesh_model *model,
 	 * The NetKey List must contain a minimum of one NetKey.
 	 */
 	if (ctx->net_idx == del_idx) {
-		send_net_key_status(model, ctx, del_idx,
-				    STATUS_CANNOT_REMOVE);
-		return;
+		return send_net_key_status(model, ctx, del_idx,
+					   STATUS_CANNOT_REMOVE);
 	}
 
-	bt_mesh_subnet_del(del_idx);
+	(void)bt_mesh_subnet_del(del_idx);
 
-	send_net_key_status(model, ctx, del_idx, STATUS_SUCCESS);
+	return send_net_key_status(model, ctx, del_idx, STATUS_SUCCESS);
 }
 
-static void net_key_get(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int net_key_get(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_NET_KEY_LIST,
 				 IDX_LEN(CONFIG_BT_MESH_SUBNET_COUNT));
@@ -1687,12 +1720,14 @@ static void net_key_get(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send NetKey List");
 	}
+
+	return 0;
 }
 
-static void send_node_id_status(struct bt_mesh_model *model,
-				struct bt_mesh_msg_ctx *ctx,
-				uint8_t status,
-				uint16_t net_idx, uint8_t node_id)
+static int send_node_id_status(struct bt_mesh_model *model,
+			       struct bt_mesh_msg_ctx *ctx,
+			       uint8_t status,
+			       uint16_t net_idx, uint8_t node_id)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_NODE_IDENTITY_STATUS, 4);
 
@@ -1704,11 +1739,13 @@ static void send_node_id_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Node Identity Status");
 	}
+
+	return 0;
 }
 
-static void node_identity_get(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int node_identity_get(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	enum bt_mesh_feat_state node_id;
 	uint8_t status;
@@ -1721,17 +1758,17 @@ static void node_identity_get(struct bt_mesh_model *model,
 	idx = net_buf_simple_pull_le16(buf);
 	if (idx > 0xfff) {
 		BT_ERR("Invalid NetKeyIndex 0x%04x", idx);
-		return;
+		return -EINVAL;
 	}
 
 	status = bt_mesh_subnet_node_id_get(idx, &node_id);
 
-	send_node_id_status(model, ctx, status, idx, node_id);
+	return send_node_id_status(model, ctx, status, idx, node_id);
 }
 
-static void node_identity_set(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int node_identity_set(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	uint8_t node_id, status;
 	uint16_t idx;
@@ -1743,30 +1780,28 @@ static void node_identity_set(struct bt_mesh_model *model,
 	idx = net_buf_simple_pull_le16(buf);
 	if (idx > 0xfff) {
 		BT_WARN("Invalid NetKeyIndex 0x%04x", idx);
-		return;
+		return -EINVAL;
 	}
 
 	node_id = net_buf_simple_pull_u8(buf);
 	if (node_id != 0x00 && node_id != 0x01) {
 		BT_WARN("Invalid Node ID value 0x%02x", node_id);
-		return;
+		return -EINVAL;
 	}
 
 	status = bt_mesh_subnet_node_id_set(idx, node_id);
 	if (status == STATUS_INVALID_NETKEY) {
-		send_node_id_status(model, ctx, status, idx,
-				    BT_MESH_NODE_IDENTITY_STOPPED);
-		return;
+		return send_node_id_status(model, ctx, status, idx,
+					   BT_MESH_NODE_IDENTITY_STOPPED);
 	}
 
 	if (status == STATUS_FEAT_NOT_SUPP) {
 		/* Should return success, even if feature isn't supported: */
-		send_node_id_status(model, ctx, STATUS_SUCCESS, idx,
-				    BT_MESH_NODE_IDENTITY_NOT_SUPPORTED);
-		return;
+		return send_node_id_status(model, ctx, STATUS_SUCCESS, idx,
+					   BT_MESH_NODE_IDENTITY_NOT_SUPPORTED);
 	}
 
-	send_node_id_status(model, ctx, status, idx, node_id);
+	return send_node_id_status(model, ctx, status, idx, node_id);
 }
 
 static void create_mod_app_status(struct net_buf_simple *msg,
@@ -1787,9 +1822,9 @@ static void create_mod_app_status(struct net_buf_simple *msg,
 	}
 }
 
-static void mod_app_bind(struct bt_mesh_model *model,
-			 struct bt_mesh_msg_ctx *ctx,
-			 struct net_buf_simple *buf)
+static int mod_app_bind(struct bt_mesh_model *model,
+			struct bt_mesh_msg_ctx *ctx,
+			struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_APP_STATUS, 9);
 	uint16_t elem_addr, key_app_idx;
@@ -1801,7 +1836,7 @@ static void mod_app_bind(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	key_app_idx = net_buf_simple_pull_le16(buf);
@@ -1842,11 +1877,13 @@ send_status:
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Model App Bind Status response");
 	}
+
+	return 0;
 }
 
-static void mod_app_unbind(struct bt_mesh_model *model,
-			   struct bt_mesh_msg_ctx *ctx,
-			   struct net_buf_simple *buf)
+static int mod_app_unbind(struct bt_mesh_model *model,
+			  struct bt_mesh_msg_ctx *ctx,
+			  struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_APP_STATUS, 9);
 	uint16_t elem_addr, key_app_idx;
@@ -1858,7 +1895,7 @@ static void mod_app_unbind(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	key_app_idx = net_buf_simple_pull_le16(buf);
@@ -1892,13 +1929,15 @@ send_status:
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Model App Unbind Status response");
 	}
+
+	return 0;
 }
 
 #define KEY_LIST_LEN (CONFIG_BT_MESH_MODEL_KEY_COUNT * 2)
 
-static void mod_app_get(struct bt_mesh_model *model,
-			struct bt_mesh_msg_ctx *ctx,
-			struct net_buf_simple *buf)
+static int mod_app_get(struct bt_mesh_model *model,
+		       struct bt_mesh_msg_ctx *ctx,
+		       struct net_buf_simple *buf)
 {
 	NET_BUF_SIMPLE_DEFINE(msg,
 			      MAX(BT_MESH_MODEL_BUF_LEN(OP_VND_MOD_APP_LIST,
@@ -1914,7 +1953,7 @@ static void mod_app_get(struct bt_mesh_model *model,
 	elem_addr = net_buf_simple_pull_le16(buf);
 	if (!BT_MESH_ADDR_IS_UNICAST(elem_addr)) {
 		BT_WARN("Prohibited element address");
-		return;
+		return -EINVAL;
 	}
 
 	mod_id = buf->data;
@@ -1966,6 +2005,8 @@ send_list:
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Model Application List message");
 	}
+
+	return 0;
 }
 
 static void reset_send_start(uint16_t duration, int err, void *cb_data)
@@ -1981,9 +2022,8 @@ static void reset_send_end(int err, void *cb_data)
 	bt_mesh_reset();
 }
 
-static void node_reset(struct bt_mesh_model *model,
-		       struct bt_mesh_msg_ctx *ctx,
-		       struct net_buf_simple *buf)
+static int node_reset(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
+		      struct net_buf_simple *buf)
 {
 	static const struct bt_mesh_send_cb reset_cb = {
 		.start = reset_send_start,
@@ -2001,10 +2041,12 @@ static void node_reset(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, &reset_cb, NULL)) {
 		BT_ERR("Unable to send Node Reset Status");
 	}
+
+	return 0;
 }
 
-static void send_friend_status(struct bt_mesh_model *model,
-			       struct bt_mesh_msg_ctx *ctx)
+static int send_friend_status(struct bt_mesh_model *model,
+			      struct bt_mesh_msg_ctx *ctx)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_FRIEND_STATUS, 1);
 
@@ -2014,22 +2056,24 @@ static void send_friend_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Friend Status");
 	}
+
+	return 0;
 }
 
-static void friend_get(struct bt_mesh_model *model,
-		       struct bt_mesh_msg_ctx *ctx,
-		       struct net_buf_simple *buf)
+static int friend_get(struct bt_mesh_model *model,
+		      struct bt_mesh_msg_ctx *ctx,
+		      struct net_buf_simple *buf)
 {
 	BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
 	       ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
 	       bt_hex(buf->data, buf->len));
 
-	send_friend_status(model, ctx);
+	return send_friend_status(model, ctx);
 }
 
-static void friend_set(struct bt_mesh_model *model,
-		       struct bt_mesh_msg_ctx *ctx,
-		       struct net_buf_simple *buf)
+static int friend_set(struct bt_mesh_model *model,
+		      struct bt_mesh_msg_ctx *ctx,
+		      struct net_buf_simple *buf)
 {
 	BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
 	       ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
@@ -2037,17 +2081,17 @@ static void friend_set(struct bt_mesh_model *model,
 
 	if (buf->data[0] != 0x00 && buf->data[0] != 0x01) {
 		BT_WARN("Invalid Friend value 0x%02x", buf->data[0]);
-		return;
+		return -EINVAL;
 	}
 
 	(void)bt_mesh_friend_set(buf->data[0]);
 
-	send_friend_status(model, ctx);
+	return send_friend_status(model, ctx);
 }
 
-static void lpn_timeout_get(struct bt_mesh_model *model,
-			    struct bt_mesh_msg_ctx *ctx,
-			    struct net_buf_simple *buf)
+static int lpn_timeout_get(struct bt_mesh_model *model,
+			   struct bt_mesh_msg_ctx *ctx,
+			   struct net_buf_simple *buf)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_LPN_TIMEOUT_STATUS, 5);
 	struct bt_mesh_friend *frnd;
@@ -2061,7 +2105,7 @@ static void lpn_timeout_get(struct bt_mesh_model *model,
 
 	if (!BT_MESH_ADDR_IS_UNICAST(lpn_addr)) {
 		BT_WARN("Invalid LPNAddress; ignoring msg");
-		return;
+		return -EINVAL;
 	}
 
 	bt_mesh_model_msg_init(&msg, OP_LPN_TIMEOUT_STATUS);
@@ -2087,11 +2131,13 @@ send_rsp:
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send LPN PollTimeout Status");
 	}
+
+	return 0;
 }
 
-static void send_krp_status(struct bt_mesh_model *model,
-			    struct bt_mesh_msg_ctx *ctx,
-			    uint16_t idx, uint8_t phase, uint8_t status)
+static int send_krp_status(struct bt_mesh_model *model,
+			   struct bt_mesh_msg_ctx *ctx, uint16_t idx,
+			   uint8_t phase, uint8_t status)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_KRP_STATUS, 4);
 
@@ -2104,9 +2150,11 @@ static void send_krp_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Key Refresh State Status");
 	}
+
+	return 0;
 }
 
-static void krp_get(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
+static int krp_get(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
 		    struct net_buf_simple *buf)
 {
 	uint8_t kr_phase, status;
@@ -2115,18 +2163,18 @@ static void krp_get(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
 	idx = net_buf_simple_pull_le16(buf);
 	if (idx > 0xfff) {
 		BT_ERR("Invalid NetKeyIndex 0x%04x", idx);
-		return;
+		return -EINVAL;
 	}
 
 	BT_DBG("idx 0x%04x", idx);
 
 	status = bt_mesh_subnet_kr_phase_get(idx, &kr_phase);
 
-	send_krp_status(model, ctx, idx, kr_phase, status);
+	return send_krp_status(model, ctx, idx, kr_phase, status);
 }
 
-static void krp_set(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
-		    struct net_buf_simple *buf)
+static int krp_set(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
+		   struct net_buf_simple *buf)
 {
 	uint8_t phase, status;
 	uint16_t idx;
@@ -2136,16 +2184,16 @@ static void krp_set(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
 
 	if (idx > 0xfff) {
 		BT_ERR("Invalid NetKeyIndex 0x%04x", idx);
-		return;
+		return -EINVAL;
 	}
 
 	status = bt_mesh_subnet_kr_phase_set(idx, &phase);
 	if (status == STATUS_CANNOT_UPDATE) {
 		BT_ERR("Invalid kr phase transition 0x%02x", phase);
-		return;
+		return -EINVAL;
 	}
 
-	send_krp_status(model, ctx, idx, phase, status);
+	return send_krp_status(model, ctx, idx, phase, status);
 }
 
 static uint8_t hb_pub_count_log(uint16_t val)
@@ -2170,9 +2218,9 @@ struct hb_pub_param {
 	uint16_t net_idx;
 } __packed;
 
-static void hb_pub_send_status(struct bt_mesh_model *model,
-			       struct bt_mesh_msg_ctx *ctx, uint8_t status,
-			       const struct bt_mesh_hb_pub *pub)
+static int hb_pub_send_status(struct bt_mesh_model *model,
+			      struct bt_mesh_msg_ctx *ctx, uint8_t status,
+			      const struct bt_mesh_hb_pub *pub)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_HEARTBEAT_PUB_STATUS, 10);
 
@@ -2192,9 +2240,11 @@ static void hb_pub_send_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Heartbeat Publication Status");
 	}
+
+	return 0;
 }
 
-static void heartbeat_pub_get(struct bt_mesh_model *model,
+static int heartbeat_pub_get(struct bt_mesh_model *model,
 			      struct bt_mesh_msg_ctx *ctx,
 			      struct net_buf_simple *buf)
 {
@@ -2204,12 +2254,12 @@ static void heartbeat_pub_get(struct bt_mesh_model *model,
 
 	bt_mesh_hb_pub_get(&pub);
 
-	hb_pub_send_status(model, ctx, STATUS_SUCCESS, &pub);
+	return hb_pub_send_status(model, ctx, STATUS_SUCCESS, &pub);
 }
 
-static void heartbeat_pub_set(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int heartbeat_pub_set(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	struct hb_pub_param *param = (void *)buf->data;
 	struct bt_mesh_hb_pub pub;
@@ -2242,23 +2292,23 @@ static void heartbeat_pub_set(struct bt_mesh_model *model,
 
 	if (param->ttl > BT_MESH_TTL_MAX && param->ttl != BT_MESH_TTL_DEFAULT) {
 		BT_ERR("Invalid TTL value 0x%02x", param->ttl);
-		return;
+		return -EINVAL;
 	}
 
 	if (pub.net_idx > 0xfff) {
 		BT_ERR("Invalid NetKeyIndex 0x%04x", pub.net_idx);
-		return;
+		return -EINVAL;
 	}
 
 	status = bt_mesh_hb_pub_set(&pub);
 
 rsp:
-	hb_pub_send_status(model, ctx, status, &pub);
+	return hb_pub_send_status(model, ctx, status, &pub);
 }
 
-static void hb_sub_send_status(struct bt_mesh_model *model,
-			       struct bt_mesh_msg_ctx *ctx,
-			       const struct bt_mesh_hb_sub *sub)
+static int hb_sub_send_status(struct bt_mesh_model *model,
+			      struct bt_mesh_msg_ctx *ctx,
+			      const struct bt_mesh_hb_sub *sub)
 {
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_HEARTBEAT_SUB_STATUS, 9);
 
@@ -2277,9 +2327,11 @@ static void hb_sub_send_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Heartbeat Subscription Status");
 	}
+
+	return 0;
 }
 
-static void heartbeat_sub_get(struct bt_mesh_model *model,
+static int heartbeat_sub_get(struct bt_mesh_model *model,
 			      struct bt_mesh_msg_ctx *ctx,
 			      struct net_buf_simple *buf)
 {
@@ -2289,17 +2341,18 @@ static void heartbeat_sub_get(struct bt_mesh_model *model,
 
 	bt_mesh_hb_sub_get(&sub);
 
-	hb_sub_send_status(model, ctx, &sub);
+	return hb_sub_send_status(model, ctx, &sub);
 }
 
-static void heartbeat_sub_set(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int heartbeat_sub_set(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	uint8_t period_log, status;
 	struct bt_mesh_hb_sub sub;
 	uint16_t sub_src, sub_dst;
 	uint32_t period;
+	int err;
 
 	BT_DBG("src 0x%04x", ctx->addr);
 
@@ -2312,7 +2365,7 @@ static void heartbeat_sub_set(struct bt_mesh_model *model,
 
 	if (period_log > 0x11) {
 		BT_WARN("Prohibited subscription period 0x%02x", period_log);
-		return;
+		return -EINVAL;
 	}
 
 	period = bt_mesh_hb_pwr2(period_log);
@@ -2322,7 +2375,7 @@ static void heartbeat_sub_set(struct bt_mesh_model *model,
 		/* All errors are caused by invalid packets, which should be
 		 * ignored.
 		 */
-		return;
+		return -EINVAL;
 	}
 
 	bt_mesh_hb_sub_get(&sub);
@@ -2334,7 +2387,10 @@ static void heartbeat_sub_set(struct bt_mesh_model *model,
 		sub.min_hops = BT_MESH_TTL_MAX;
 	}
 
-	hb_sub_send_status(model, ctx, &sub);
+	err = hb_sub_send_status(model, ctx, &sub);
+	if (err) {
+		return err;
+	}
 
 	/* MESH/NODE/CFG/HBS/BV-02-C expects us to return previous
 	 * count value and then reset it to 0.
@@ -2343,6 +2399,8 @@ static void heartbeat_sub_set(struct bt_mesh_model *model,
 	    sub.dst != BT_MESH_ADDR_UNASSIGNED && !period) {
 		bt_mesh_hb_sub_reset_count();
 	}
+
+	return 0;
 }
 
 const struct bt_mesh_model_op bt_mesh_cfg_srv_op[] = {
diff --git a/subsys/bluetooth/mesh/health_cli.c b/subsys/bluetooth/mesh/health_cli.c
index cf148271fc0..b0419f1cb18 100644
--- a/subsys/bluetooth/mesh/health_cli.c
+++ b/subsys/bluetooth/mesh/health_cli.c
@@ -35,9 +35,9 @@ struct health_fault_param {
 	size_t *fault_count;
 };
 
-static void health_fault_status(struct bt_mesh_model *model,
-				struct bt_mesh_msg_ctx *ctx,
-				struct net_buf_simple *buf)
+static int health_fault_status(struct bt_mesh_model *model,
+			       struct bt_mesh_msg_ctx *ctx,
+			       struct net_buf_simple *buf)
 {
 	struct health_fault_param *param;
 	uint8_t test_id;
@@ -49,19 +49,19 @@ static void health_fault_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&health_cli->ack_ctx, OP_HEALTH_FAULT_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	test_id = net_buf_simple_pull_u8(buf);
 	if (param->expect_test_id && test_id != *param->expect_test_id) {
 		BT_WARN("Health fault with unexpected Test ID");
-		return;
+		return -ENOENT;
 	}
 
 	cid = net_buf_simple_pull_le16(buf);
 	if (cid != param->cid) {
 		BT_WARN("Health fault with unexpected Company ID");
-		return;
+		return -ENOENT;
 	}
 
 	if (param->test_id) {
@@ -77,11 +77,13 @@ static void health_fault_status(struct bt_mesh_model *model,
 	memcpy(param->faults, buf->data, *param->fault_count);
 
 	bt_mesh_msg_ack_ctx_rx(&health_cli->ack_ctx);
+
+	return 0;
 }
 
-static void health_current_status(struct bt_mesh_model *model,
-				  struct bt_mesh_msg_ctx *ctx,
-				  struct net_buf_simple *buf)
+static int health_current_status(struct bt_mesh_model *model,
+				 struct bt_mesh_msg_ctx *ctx,
+				 struct net_buf_simple *buf)
 {
 	struct bt_mesh_health_cli *cli = model->user_data;
 	uint8_t test_id;
@@ -99,19 +101,21 @@ static void health_current_status(struct bt_mesh_model *model,
 
 	if (!cli->current_status) {
 		BT_WARN("No Current Status callback available");
-		return;
+		return 0;
 	}
 
 	cli->current_status(cli, ctx->addr, test_id, cid, buf->data, buf->len);
+
+	return 0;
 }
 
 struct health_period_param {
 	uint8_t *divisor;
 };
 
-static void health_period_status(struct bt_mesh_model *model,
-				 struct bt_mesh_msg_ctx *ctx,
-				 struct net_buf_simple *buf)
+static int health_period_status(struct bt_mesh_model *model,
+				struct bt_mesh_msg_ctx *ctx,
+				struct net_buf_simple *buf)
 {
 	struct health_period_param *param;
 
@@ -121,21 +125,23 @@ static void health_period_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&health_cli->ack_ctx, OP_HEALTH_PERIOD_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	*param->divisor = net_buf_simple_pull_u8(buf);
 
 	bt_mesh_msg_ack_ctx_rx(&health_cli->ack_ctx);
+
+	return 0;
 }
 
 struct health_attention_param {
 	uint8_t *attention;
 };
 
-static void health_attention_status(struct bt_mesh_model *model,
-				    struct bt_mesh_msg_ctx *ctx,
-				    struct net_buf_simple *buf)
+static int health_attention_status(struct bt_mesh_model *model,
+				   struct bt_mesh_msg_ctx *ctx,
+				   struct net_buf_simple *buf)
 {
 	struct health_attention_param *param;
 
@@ -145,7 +151,7 @@ static void health_attention_status(struct bt_mesh_model *model,
 
 	if (!bt_mesh_msg_ack_ctx_match(&health_cli->ack_ctx, OP_ATTENTION_STATUS, ctx->addr,
 				       (void **)&param)) {
-		return;
+		return -ENOENT;
 	}
 
 	if (param->attention) {
@@ -153,6 +159,8 @@ static void health_attention_status(struct bt_mesh_model *model,
 	}
 
 	bt_mesh_msg_ack_ctx_rx(&health_cli->ack_ctx);
+
+	return 0;
 }
 
 const struct bt_mesh_model_op bt_mesh_health_cli_op[] = {
diff --git a/subsys/bluetooth/mesh/health_srv.c b/subsys/bluetooth/mesh/health_srv.c
index 1a52007e51d..e765ffb6356 100644
--- a/subsys/bluetooth/mesh/health_srv.c
+++ b/subsys/bluetooth/mesh/health_srv.c
@@ -72,7 +72,6 @@ static size_t health_get_current(struct bt_mesh_model *mod,
 	uint8_t *test_id, *company_ptr;
 	uint16_t company_id;
 	uint8_t fault_count;
-	int err;
 
 	bt_mesh_model_msg_init(msg, OP_HEALTH_CURRENT_STATUS);
 
@@ -82,6 +81,8 @@ static size_t health_get_current(struct bt_mesh_model *mod,
 
 	if (srv->cb && srv->cb->fault_get_cur) {
 		fault_count = net_buf_simple_tailroom(msg);
+		int err;
+
 		err = srv->cb->fault_get_cur(mod, test_id, &company_id,
 					     net_buf_simple_tail(msg),
 					     &fault_count);
@@ -104,9 +105,9 @@ static size_t health_get_current(struct bt_mesh_model *mod,
 	return fault_count;
 }
 
-static void health_fault_get(struct bt_mesh_model *model,
-			     struct bt_mesh_msg_ctx *ctx,
-			     struct net_buf_simple *buf)
+static int health_fault_get(struct bt_mesh_model *model,
+			    struct bt_mesh_msg_ctx *ctx,
+			    struct net_buf_simple *buf)
 {
 	NET_BUF_SIMPLE_DEFINE(sdu, BT_MESH_TX_SDU_MAX);
 	uint16_t company_id;
@@ -120,11 +121,13 @@ static void health_fault_get(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &sdu, NULL, NULL)) {
 		BT_ERR("Unable to send Health Current Status response");
 	}
+
+	return 0;
 }
 
-static void health_fault_clear_unrel(struct bt_mesh_model *model,
-				     struct bt_mesh_msg_ctx *ctx,
-				     struct net_buf_simple *buf)
+static int health_fault_clear_unrel(struct bt_mesh_model *model,
+				    struct bt_mesh_msg_ctx *ctx,
+				    struct net_buf_simple *buf)
 {
 	struct bt_mesh_health_srv *srv = model->user_data;
 	uint16_t company_id;
@@ -134,13 +137,15 @@ static void health_fault_clear_unrel(struct bt_mesh_model *model,
 	BT_DBG("company_id 0x%04x", company_id);
 
 	if (srv->cb && srv->cb->fault_clear) {
-		srv->cb->fault_clear(model, company_id);
+		return srv->cb->fault_clear(model, company_id);
 	}
+
+	return 0;
 }
 
-static void health_fault_clear(struct bt_mesh_model *model,
-			       struct bt_mesh_msg_ctx *ctx,
-			       struct net_buf_simple *buf)
+static int health_fault_clear(struct bt_mesh_model *model,
+			      struct bt_mesh_msg_ctx *ctx,
+			      struct net_buf_simple *buf)
 {
 	NET_BUF_SIMPLE_DEFINE(sdu, BT_MESH_TX_SDU_MAX);
 	struct bt_mesh_health_srv *srv = model->user_data;
@@ -151,7 +156,12 @@ static void health_fault_clear(struct bt_mesh_model *model,
 	BT_DBG("company_id 0x%04x", company_id);
 
 	if (srv->cb && srv->cb->fault_clear) {
-		srv->cb->fault_clear(model, company_id);
+		int err;
+
+		err = srv->cb->fault_clear(model, company_id);
+		if (err) {
+			return err;
+		}
 	}
 
 	health_get_registered(model, company_id, &sdu);
@@ -159,9 +169,11 @@ static void health_fault_clear(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &sdu, NULL, NULL)) {
 		BT_ERR("Unable to send Health Current Status response");
 	}
+
+	return 0;
 }
 
-static void health_fault_test_unrel(struct bt_mesh_model *model,
+static int health_fault_test_unrel(struct bt_mesh_model *model,
 				    struct bt_mesh_msg_ctx *ctx,
 				    struct net_buf_simple *buf)
 {
@@ -175,13 +187,15 @@ static void health_fault_test_unrel(struct bt_mesh_model *model,
 	BT_DBG("test 0x%02x company 0x%04x", test_id, company_id);
 
 	if (srv->cb && srv->cb->fault_test) {
-		srv->cb->fault_test(model, test_id, company_id);
+		return srv->cb->fault_test(model, test_id, company_id);
 	}
+
+	return 0;
 }
 
-static void health_fault_test(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int health_fault_test(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	NET_BUF_SIMPLE_DEFINE(sdu, BT_MESH_TX_SDU_MAX);
 	struct bt_mesh_health_srv *srv = model->user_data;
@@ -201,7 +215,7 @@ static void health_fault_test(struct bt_mesh_model *model,
 		err = srv->cb->fault_test(model, test_id, company_id);
 		if (err) {
 			BT_WARN("Running fault test failed with err %d", err);
-			return;
+			return err;
 		}
 	}
 
@@ -210,10 +224,12 @@ static void health_fault_test(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &sdu, NULL, NULL)) {
 		BT_ERR("Unable to send Health Current Status response");
 	}
+
+	return 0;
 }
 
-static void send_attention_status(struct bt_mesh_model *model,
-				  struct bt_mesh_msg_ctx *ctx)
+static int send_attention_status(struct bt_mesh_model *model,
+				 struct bt_mesh_msg_ctx *ctx)
 {
 	/* Needed size: opcode (2 bytes) + msg + MIC */
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_ATTENTION_STATUS, 1);
@@ -231,20 +247,22 @@ static void send_attention_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Attention Status");
 	}
+
+	return 0;
 }
 
-static void attention_get(struct bt_mesh_model *model,
-			  struct bt_mesh_msg_ctx *ctx,
-			  struct net_buf_simple *buf)
+static int attention_get(struct bt_mesh_model *model,
+			 struct bt_mesh_msg_ctx *ctx,
+			 struct net_buf_simple *buf)
 {
 	BT_DBG("");
 
-	send_attention_status(model, ctx);
+	return send_attention_status(model, ctx);
 }
 
-static void attention_set_unrel(struct bt_mesh_model *model,
-				struct bt_mesh_msg_ctx *ctx,
-				struct net_buf_simple *buf)
+static int attention_set_unrel(struct bt_mesh_model *model,
+			       struct bt_mesh_msg_ctx *ctx,
+			       struct net_buf_simple *buf)
 {
 	uint8_t time;
 
@@ -253,21 +271,23 @@ static void attention_set_unrel(struct bt_mesh_model *model,
 	BT_DBG("%u second%s", time, (time == 1U) ? "" : "s");
 
 	bt_mesh_attention(model, time);
+
+	return 0;
 }
 
-static void attention_set(struct bt_mesh_model *model,
-			  struct bt_mesh_msg_ctx *ctx,
-			  struct net_buf_simple *buf)
+static int attention_set(struct bt_mesh_model *model,
+			 struct bt_mesh_msg_ctx *ctx,
+			 struct net_buf_simple *buf)
 {
 	BT_DBG("");
 
 	attention_set_unrel(model, ctx, buf);
 
-	send_attention_status(model, ctx);
+	return send_attention_status(model, ctx);
 }
 
-static void send_health_period_status(struct bt_mesh_model *model,
-				      struct bt_mesh_msg_ctx *ctx)
+static int send_health_period_status(struct bt_mesh_model *model,
+				     struct bt_mesh_msg_ctx *ctx)
 {
 	/* Needed size: opcode (2 bytes) + msg + MIC */
 	BT_MESH_MODEL_BUF_DEFINE(msg, OP_HEALTH_PERIOD_STATUS, 1);
@@ -279,18 +299,20 @@ static void send_health_period_status(struct bt_mesh_model *model,
 	if (bt_mesh_model_send(model, ctx, &msg, NULL, NULL)) {
 		BT_ERR("Unable to send Health Period Status");
 	}
+
+	return 0;
 }
 
-static void health_period_get(struct bt_mesh_model *model,
+static int health_period_get(struct bt_mesh_model *model,
 			      struct bt_mesh_msg_ctx *ctx,
 			      struct net_buf_simple *buf)
 {
 	BT_DBG("");
 
-	send_health_period_status(model, ctx);
+	return send_health_period_status(model, ctx);
 }
 
-static void health_period_set_unrel(struct bt_mesh_model *model,
+static int health_period_set_unrel(struct bt_mesh_model *model,
 				    struct bt_mesh_msg_ctx *ctx,
 				    struct net_buf_simple *buf)
 {
@@ -299,23 +321,25 @@ static void health_period_set_unrel(struct bt_mesh_model *model,
 	period = net_buf_simple_pull_u8(buf);
 	if (period > 15) {
 		BT_WARN("Prohibited period value %u", period);
-		return;
+		return -EINVAL;
 	}
 
 	BT_DBG("period %u", period);
 
 	model->pub->period_div = period;
+
+	return 0;
 }
 
-static void health_period_set(struct bt_mesh_model *model,
-			      struct bt_mesh_msg_ctx *ctx,
-			      struct net_buf_simple *buf)
+static int health_period_set(struct bt_mesh_model *model,
+			     struct bt_mesh_msg_ctx *ctx,
+			     struct net_buf_simple *buf)
 {
 	BT_DBG("");
 
 	health_period_set_unrel(model, ctx, buf);
 
-	send_health_period_status(model, ctx);
+	return send_health_period_status(model, ctx);
 }
 
 const struct bt_mesh_model_op bt_mesh_health_srv_op[] = {