diff --git a/include/zephyr/bluetooth/audio/bap.h b/include/zephyr/bluetooth/audio/bap.h
index f18c034a1b3..ccae126e0bc 100644
--- a/include/zephyr/bluetooth/audio/bap.h
+++ b/include/zephyr/bluetooth/audio/bap.h
@@ -1156,7 +1156,7 @@ struct bt_bap_unicast_group_param {
 };
 
 /**
- * @brief Create audio unicast group.
+ * @brief Create unicast group.
  *
  * Create a new audio unicast group with one or more audio streams as a unicast client.
  * All streams shall share the same framing.
@@ -1171,6 +1171,24 @@ struct bt_bap_unicast_group_param {
 int bt_bap_unicast_group_create(struct bt_bap_unicast_group_param *param,
 				struct bt_bap_unicast_group **unicast_group);
 
+/**
+ * @brief Reconfigure unicast group.
+ *
+ * Reconfigure a unicast group with one or more audio streams as a unicast client.
+ * All streams shall share the same framing.
+ * All streams in the same direction shall share the same interval and latency (see
+ * @ref bt_audio_codec_qos).
+ * All streams in @p param shall already belong to @p unicast_group.
+ * Use bt_bap_unicast_group_add_streams() to add additional streams.
+ *
+ * @param unicast_group  Pointer to the unicast group created.
+ * @param param          The unicast group reconfigure parameters.
+ *
+ * @return Zero on success or (negative) error code otherwise.
+ */
+int bt_bap_unicast_group_reconfig(struct bt_bap_unicast_group *unicast_group,
+				  const struct bt_bap_unicast_group_param *param);
+
 /**
  * @brief Add streams to a unicast group as a unicast client
  *
diff --git a/subsys/bluetooth/audio/bap_endpoint.h b/subsys/bluetooth/audio/bap_endpoint.h
index cd6165b4483..85d3cea3e4f 100644
--- a/subsys/bluetooth/audio/bap_endpoint.h
+++ b/subsys/bluetooth/audio/bap_endpoint.h
@@ -85,6 +85,10 @@ struct bt_bap_unicast_group {
 	/* Unicast group fields */
 	uint8_t index;
 	bool allocated;
+	/* Used to determine whether any stream in this group has been started which will prevent
+	 * reconfiguring it
+	 */
+	bool has_been_connected;
 	struct bt_iso_cig *cig;
 	/* The ISO API for CIG creation requires an array of pointers to ISO channels */
 	struct bt_iso_chan *cis[UNICAST_GROUP_STREAM_CNT];
diff --git a/subsys/bluetooth/audio/bap_unicast_client.c b/subsys/bluetooth/audio/bap_unicast_client.c
index 51a34d92d8f..9b51d43b2f0 100644
--- a/subsys/bluetooth/audio/bap_unicast_client.c
+++ b/subsys/bluetooth/audio/bap_unicast_client.c
@@ -318,6 +318,10 @@ static void unicast_client_ep_iso_connected(struct bt_bap_ep *ep)
 	const struct bt_bap_stream_ops *stream_ops;
 	struct bt_bap_stream *stream;
 
+	if (ep->unicast_group != NULL) {
+		ep->unicast_group->has_been_connected = true;
+	}
+
 	if (ep->status.state != BT_BAP_EP_STATE_ENABLING) {
 		LOG_DBG("endpoint not in enabling state: %s",
 			bt_bap_ep_state_str(ep->status.state));
@@ -2171,17 +2175,12 @@ static void bt_audio_codec_qos_to_cig_param(struct bt_iso_cig_param *cig_param,
 	}
 }
 
-static int bt_audio_cig_create(struct bt_bap_unicast_group *group)
+static uint8_t unicast_group_get_cis_count(const struct bt_bap_unicast_group *unicast_group)
 {
-	struct bt_iso_cig_param param = {0};
-	uint8_t cis_count;
-	int err;
+	uint8_t cis_count = 0U;
 
-	LOG_DBG("group %p", group);
-
-	cis_count = 0U;
-	for (size_t i = 0U; i < ARRAY_SIZE(group->cis); i++) {
-		if (group->cis[i] == NULL) {
+	for (size_t i = 0U; i < ARRAY_SIZE(unicast_group->cis); i++) {
+		if (unicast_group->cis[i] == NULL) {
 			/* A NULL CIS acts as a NULL terminator */
 			break;
 		}
@@ -2189,7 +2188,17 @@ static int bt_audio_cig_create(struct bt_bap_unicast_group *group)
 		cis_count++;
 	}
 
-	param.num_cis = cis_count;
+	return cis_count;
+}
+
+static int bt_audio_cig_create(struct bt_bap_unicast_group *group)
+{
+	struct bt_iso_cig_param param = {0};
+	int err;
+
+	LOG_DBG("group %p", group);
+
+	param.num_cis = unicast_group_get_cis_count(group);
 	param.cis_channels = group->cis;
 	bt_audio_codec_qos_to_cig_param(&param, group);
 
@@ -2352,6 +2361,27 @@ static void unicast_client_codec_qos_to_iso_qos(struct bt_bap_iso *iso,
 	}
 }
 
+static void unicast_group_set_iso_stream_param(struct bt_bap_unicast_group *group,
+					       struct bt_bap_iso *iso,
+					       struct bt_audio_codec_qos *qos,
+					       enum bt_audio_dir dir)
+{
+	/* Store the stream Codec QoS in the bap_iso */
+	unicast_client_codec_qos_to_iso_qos(iso, qos, dir);
+
+	/* Store the group Codec QoS in the group - This assume thats the parameters have been
+	 * verified first
+	 */
+	group->cig_param.framing = qos->framing;
+	if (dir == BT_AUDIO_DIR_SOURCE) {
+		group->cig_param.p_to_c_interval = qos->interval;
+		group->cig_param.p_to_c_latency = qos->latency;
+	} else {
+		group->cig_param.c_to_p_interval = qos->interval;
+		group->cig_param.c_to_p_latency = qos->latency;
+	}
+}
+
 static void unicast_group_add_stream(struct bt_bap_unicast_group *group,
 				     struct bt_bap_unicast_group_stream_param *param,
 				     struct bt_bap_iso *iso, enum bt_audio_dir dir)
@@ -2372,20 +2402,7 @@ static void unicast_group_add_stream(struct bt_bap_unicast_group *group,
 		bt_bap_iso_bind_ep(iso, stream->ep);
 	}
 
-	/* Store the stream Codec QoS in the bap_iso */
-	unicast_client_codec_qos_to_iso_qos(iso, qos, dir);
-
-	/* Store the group Codec QoS in the group - This assume thats the parameters have been
-	 * verified first
-	 */
-	group->cig_param.framing = qos->framing;
-	if (dir == BT_AUDIO_DIR_SOURCE) {
-		group->cig_param.p_to_c_interval = qos->interval;
-		group->cig_param.p_to_c_latency = qos->latency;
-	} else {
-		group->cig_param.c_to_p_interval = qos->interval;
-		group->cig_param.c_to_p_latency = qos->latency;
-	}
+	unicast_group_set_iso_stream_param(group, iso, qos, dir);
 
 	sys_slist_append(&group->streams, &stream->_node);
 }
@@ -2574,7 +2591,8 @@ static int stream_pair_param_check(const struct bt_bap_unicast_group_stream_pair
 }
 
 /** Validates that the stream parameter does not contain invalid values  */
-static bool valid_unicast_group_stream_param(const struct bt_bap_unicast_group_stream_param *param,
+static bool valid_unicast_group_stream_param(const struct bt_bap_unicast_group *unicast_group,
+					     const struct bt_bap_unicast_group_stream_param *param,
 					     struct bt_bap_unicast_group_cig_param *cig_param,
 					     enum bt_audio_dir dir)
 {
@@ -2591,7 +2609,13 @@ static bool valid_unicast_group_stream_param(const struct bt_bap_unicast_group_s
 	}
 
 	if (param->stream != NULL && param->stream->group != NULL) {
-		LOG_DBG("stream %p already part of group %p", param->stream, param->stream->group);
+		if (unicast_group != NULL && param->stream->group != unicast_group) {
+			LOG_DBG("stream %p not part of group %p (%p)", param->stream, unicast_group,
+				param->stream->group);
+		} else {
+			LOG_DBG("stream %p already part of group %p", param->stream,
+				param->stream->group);
+		}
 		return -EALREADY;
 	}
 
@@ -2659,15 +2683,15 @@ valid_group_stream_pair_param(const struct bt_bap_unicast_group *unicast_group,
 	}
 
 	if (pair_param->rx_param != NULL) {
-		if (!valid_unicast_group_stream_param(pair_param->rx_param, &cig_param,
-						      BT_AUDIO_DIR_SOURCE)) {
+		if (!valid_unicast_group_stream_param(unicast_group, pair_param->rx_param,
+						      &cig_param, BT_AUDIO_DIR_SOURCE)) {
 			return false;
 		}
 	}
 
 	if (pair_param->tx_param != NULL) {
-		if (!valid_unicast_group_stream_param(pair_param->tx_param, &cig_param,
-						      BT_AUDIO_DIR_SINK)) {
+		if (!valid_unicast_group_stream_param(unicast_group, pair_param->tx_param,
+						      &cig_param, BT_AUDIO_DIR_SINK)) {
 			return false;
 		}
 	}
@@ -2675,7 +2699,7 @@ valid_group_stream_pair_param(const struct bt_bap_unicast_group *unicast_group,
 	return true;
 }
 
-static bool valid_unicast_group_param(const struct bt_bap_unicast_group *unicast_group,
+static bool valid_unicast_group_param(struct bt_bap_unicast_group *unicast_group,
 				      const struct bt_bap_unicast_group_param *param)
 {
 	CHECKIF(param == NULL) {
@@ -2689,6 +2713,17 @@ static bool valid_unicast_group_param(const struct bt_bap_unicast_group *unicast
 		return false;
 	}
 
+	if (unicast_group != NULL) {
+		const size_t group_cis_cnt = unicast_group_get_cis_count(unicast_group);
+
+		if (param->params_count != group_cis_cnt) {
+			LOG_DBG("Mismatch between group CIS count (%zu) and params_count (%zu)",
+				group_cis_cnt, param->params_count);
+
+			return false;
+		}
+	}
+
 	for (size_t i = 0U; i < param->params_count; i++) {
 		if (!valid_group_stream_pair_param(unicast_group, &param->params[i])) {
 			return false;
@@ -2718,7 +2753,7 @@ int bt_bap_unicast_group_create(struct bt_bap_unicast_group_param *param,
 		return -ENOMEM;
 	}
 
-	if (!valid_unicast_group_param(unicast_group, param)) {
+	if (!valid_unicast_group_param(NULL, param)) {
 		unicast_group_free(unicast_group);
 
 		return -EINVAL;
@@ -2758,6 +2793,91 @@ int bt_bap_unicast_group_create(struct bt_bap_unicast_group_param *param,
 	return 0;
 }
 
+int bt_bap_unicast_group_reconfig(struct bt_bap_unicast_group *unicast_group,
+				  const struct bt_bap_unicast_group_param *param)
+{
+	struct bt_iso_chan_io_qos rx_io_qos_backup[UNICAST_GROUP_STREAM_CNT];
+	struct bt_iso_chan_io_qos tx_io_qos_backup[UNICAST_GROUP_STREAM_CNT];
+	struct bt_bap_unicast_group_cig_param cig_param_backup;
+	struct bt_bap_stream *tmp_stream;
+	size_t idx;
+	int err;
+
+	IF_ENABLED(CONFIG_BT_ISO_TEST_PARAMS,
+		   (uint8_t num_subevents_backup[UNICAST_GROUP_STREAM_CNT]));
+
+	CHECKIF(unicast_group == NULL) {
+		LOG_DBG("unicast_group is NULL");
+		return -EINVAL;
+	}
+
+	if (unicast_group->has_been_connected) {
+		LOG_DBG("Cannot modify a unicast_group where a CIS has been connected");
+		return -EINVAL;
+	}
+
+	if (!valid_unicast_group_param(unicast_group, param)) {
+		return -EINVAL;
+	}
+
+	/* Make backups of the values in case that the reconfigure request is rejected by e.g. the
+	 * controller
+	 */
+	idx = 0U;
+	SYS_SLIST_FOR_EACH_CONTAINER(&unicast_group->streams, tmp_stream, _node) {
+		memcpy(&rx_io_qos_backup[idx], tmp_stream->bap_iso->chan.qos->rx,
+		       sizeof(rx_io_qos_backup[idx]));
+		memcpy(&tx_io_qos_backup[idx], tmp_stream->bap_iso->chan.qos->tx,
+		       sizeof(tx_io_qos_backup[idx]));
+		IF_ENABLED(
+			CONFIG_BT_ISO_TEST_PARAMS,
+			(num_subevents_backup[idx] = tmp_stream->bap_iso->chan.qos->num_subevents));
+		idx++;
+	}
+	memcpy(&cig_param_backup, &unicast_group->cig_param, sizeof(cig_param_backup));
+
+	/* Update the stream and group parameters */
+	for (size_t i = 0U; i < param->params_count; i++) {
+		struct bt_bap_unicast_group_stream_pair_param *stream_param = &param->params[i];
+		struct bt_bap_unicast_group_stream_param *rx_param = stream_param->rx_param;
+		struct bt_bap_unicast_group_stream_param *tx_param = stream_param->tx_param;
+
+		if (rx_param != NULL) {
+			unicast_group_set_iso_stream_param(unicast_group, rx_param->stream->bap_iso,
+							   rx_param->qos, BT_AUDIO_DIR_SOURCE);
+		}
+
+		if (tx_param != NULL) {
+			unicast_group_set_iso_stream_param(unicast_group, tx_param->stream->bap_iso,
+							   tx_param->qos, BT_AUDIO_DIR_SOURCE);
+		}
+	}
+
+	/* Reconfigure the CIG based on the above new values */
+	err = bt_audio_cig_reconfigure(unicast_group);
+	if (err != 0) {
+		LOG_DBG("bt_audio_cig_reconfigure failed: %d", err);
+
+		/* Revert any changes above */
+		memcpy(&unicast_group->cig_param, &cig_param_backup, sizeof(cig_param_backup));
+		idx = 0U;
+		SYS_SLIST_FOR_EACH_CONTAINER(&unicast_group->streams, tmp_stream, _node) {
+			memcpy(tmp_stream->bap_iso->chan.qos->rx, &rx_io_qos_backup[idx],
+			       sizeof(rx_io_qos_backup[idx]));
+			memcpy(tmp_stream->bap_iso->chan.qos->tx, &tx_io_qos_backup[idx],
+			       sizeof(tx_io_qos_backup[idx]));
+			IF_ENABLED(CONFIG_BT_ISO_TEST_PARAMS,
+				   (tmp_stream->bap_iso->chan.qos->num_subevents =
+					    num_subevents_backup[idx]));
+			idx++;
+		}
+
+		return err;
+	}
+
+	return 0;
+}
+
 int bt_bap_unicast_group_add_streams(struct bt_bap_unicast_group *unicast_group,
 				       struct bt_bap_unicast_group_stream_pair_param params[],
 				       size_t num_param)
@@ -2774,6 +2894,11 @@ int bt_bap_unicast_group_add_streams(struct bt_bap_unicast_group *unicast_group,
 		return -EINVAL;
 	}
 
+	if (unicast_group->has_been_connected) {
+		LOG_DBG("Cannot modify a unicast_group where a CIS has been connected");
+		return -EINVAL;
+	}
+
 	CHECKIF(params == NULL)
 	{
 		LOG_DBG("params is NULL");
diff --git a/subsys/bluetooth/audio/shell/bap.c b/subsys/bluetooth/audio/shell/bap.c
index 9dcffab1635..64d2b8e1a9b 100644
--- a/subsys/bluetooth/audio/shell/bap.c
+++ b/subsys/bluetooth/audio/shell/bap.c
@@ -1437,19 +1437,14 @@ static int cmd_stream_qos(const struct shell *sh, size_t argc, char *argv[])
 	return 0;
 }
 
-static int create_unicast_group(const struct shell *sh)
+static int set_group_param(
+	const struct shell *sh, struct bt_bap_unicast_group_param *group_param,
+	struct bt_bap_unicast_group_stream_pair_param pair_param[ARRAY_SIZE(unicast_streams)],
+	struct bt_bap_unicast_group_stream_param stream_params[ARRAY_SIZE(unicast_streams)])
 {
-	struct bt_bap_unicast_group_stream_pair_param pair_param[ARRAY_SIZE(unicast_streams)];
-	struct bt_bap_unicast_group_stream_param stream_params[ARRAY_SIZE(unicast_streams)];
-	struct bt_bap_unicast_group_param group_param;
 	size_t source_cnt = 0;
 	size_t sink_cnt = 0;
 	size_t cnt = 0;
-	int err;
-
-	memset(pair_param, 0, sizeof(pair_param));
-	memset(stream_params, 0, sizeof(stream_params));
-	memset(&group_param, 0, sizeof(group_param));
 
 	for (size_t i = 0U; i < ARRAY_SIZE(unicast_streams); i++) {
 		struct bt_bap_stream *stream = bap_stream_from_shell_stream(&unicast_streams[i]);
@@ -1479,16 +1474,50 @@ static int create_unicast_group(const struct shell *sh)
 		return -ENOEXEC;
 	}
 
-	group_param.packing = BT_ISO_PACKING_SEQUENTIAL;
-	group_param.params = pair_param;
-	group_param.params_count = MAX(source_cnt, sink_cnt);
+	group_param->packing = BT_ISO_PACKING_SEQUENTIAL;
+	group_param->params = pair_param;
+	group_param->params_count = MAX(source_cnt, sink_cnt);
 
-	err = bt_bap_unicast_group_create(&group_param,
-					    &default_unicast_group);
+	return 0;
+}
+
+static int create_unicast_group(const struct shell *sh)
+{
+	struct bt_bap_unicast_group_stream_pair_param pair_param[ARRAY_SIZE(unicast_streams)] = {0};
+	struct bt_bap_unicast_group_stream_param stream_params[ARRAY_SIZE(unicast_streams)] = {0};
+	struct bt_bap_unicast_group_param group_param = {0};
+	int err;
+
+	err = set_group_param(sh, &group_param, pair_param, stream_params);
 	if (err != 0) {
-		shell_error(sh,
-			    "Unable to create default unicast group: %d",
-			    err);
+		return err;
+	}
+
+	err = bt_bap_unicast_group_create(&group_param, &default_unicast_group);
+	if (err != 0) {
+		shell_error(sh, "Unable to create default unicast group: %d", err);
+
+		return -ENOEXEC;
+	}
+
+	return 0;
+}
+
+static int reconfig_unicast_group(const struct shell *sh)
+{
+	struct bt_bap_unicast_group_stream_pair_param pair_param[ARRAY_SIZE(unicast_streams)] = {0};
+	struct bt_bap_unicast_group_stream_param stream_params[ARRAY_SIZE(unicast_streams)] = {0};
+	struct bt_bap_unicast_group_param group_param = {0};
+	int err;
+
+	err = set_group_param(sh, &group_param, pair_param, stream_params);
+	if (err != 0) {
+		return err;
+	}
+
+	err = bt_bap_unicast_group_reconfig(default_unicast_group, &group_param);
+	if (err != 0) {
+		shell_error(sh, "Unable to create default unicast group: %d", err);
 
 		return -ENOEXEC;
 	}
@@ -1515,6 +1544,11 @@ static int cmd_qos(const struct shell *sh, size_t argc, char *argv[])
 		if (err != 0) {
 			return err;
 		}
+	} else {
+		err = reconfig_unicast_group(sh);
+		if (err != 0) {
+			return err;
+		}
 	}
 
 	err = bt_bap_stream_qos(default_conn, default_unicast_group);
diff --git a/tests/bsim/bluetooth/audio/src/bap_unicast_client_test.c b/tests/bsim/bluetooth/audio/src/bap_unicast_client_test.c
index a92fd610bb1..f96b3064186 100644
--- a/tests/bsim/bluetooth/audio/src/bap_unicast_client_test.c
+++ b/tests/bsim/bluetooth/audio/src/bap_unicast_client_test.c
@@ -1233,6 +1233,53 @@ static void test_main_async_group(void)
 	PASS("Unicast client async group parameters passed\n");
 }
 
+static void test_main_reconf_group(void)
+{
+	static struct bt_bap_lc3_preset preset_16_2_2 = BT_BAP_LC3_UNICAST_PRESET_16_2_2(
+		BT_AUDIO_LOCATION_FRONT_LEFT, BT_AUDIO_CONTEXT_TYPE_UNSPECIFIED);
+	struct bt_bap_stream rx_stream = {0};
+	struct bt_bap_stream tx_stream = {0};
+	struct bt_bap_unicast_group_stream_param rx_param = {
+		.qos = &preset_16_2_1.qos,
+		.stream = &rx_stream,
+	};
+	struct bt_bap_unicast_group_stream_param tx_param = {
+		.qos = &preset_16_2_1.qos,
+		.stream = &tx_stream,
+	};
+	struct bt_bap_unicast_group_stream_pair_param pair_param = {
+		.rx_param = &rx_param,
+		.tx_param = &tx_param,
+	};
+	struct bt_bap_unicast_group_param param = {
+		.params = &pair_param,
+		.params_count = 1U,
+		.packing = BT_ISO_PACKING_SEQUENTIAL,
+	};
+	struct bt_bap_unicast_group *unicast_group;
+	int err;
+
+	init();
+
+	err = bt_bap_unicast_group_create(&param, &unicast_group);
+	if (err != 0) {
+		FAIL("Unable to create unicast group: %d", err);
+
+		return;
+	}
+
+	rx_param.qos = &preset_16_2_2.qos;
+	tx_param.qos = &preset_16_2_2.qos;
+	err = bt_bap_unicast_group_reconfig(unicast_group, &param);
+	if (err != 0) {
+		FAIL("Unable to reconfigure unicast group: %d", err);
+
+		return;
+	}
+
+	PASS("Unicast client async group parameters passed\n");
+}
+
 static const struct bst_test_instance test_unicast_client[] = {
 	{
 		.test_id = "unicast_client",
@@ -1255,6 +1302,13 @@ static const struct bst_test_instance test_unicast_client[] = {
 			      "values in each direction, such as 10000us SDU interval in C to P "
 			      "and 7500us for P to C",
 	},
+	{
+		.test_id = "unicast_client_reconf_group",
+		.test_pre_init_f = test_init,
+		.test_tick_f = test_tick,
+		.test_main_f = test_main_reconf_group,
+		.test_descr = "Tests that a unicast group (CIG) can be reconfigred with new values",
+	},
 	BSTEST_END_MARKER,
 };
 
diff --git a/tests/bsim/bluetooth/audio/test_scripts/bap_unicast_client_reconf_group.sh b/tests/bsim/bluetooth/audio/test_scripts/bap_unicast_client_reconf_group.sh
new file mode 100755
index 00000000000..3b66ce83158
--- /dev/null
+++ b/tests/bsim/bluetooth/audio/test_scripts/bap_unicast_client_reconf_group.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2021-2024 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+
+SIMULATION_ID="bap_unicast_client_reconf_group"
+VERBOSITY_LEVEL=2
+
+source ${ZEPHYR_BASE}/tests/bsim/sh_common.source
+
+cd ${BSIM_OUT_PATH}/bin
+
+printf "\n\n======== BAP Unicast Client Reconfigure Group parameters test =========\n\n"
+
+Execute ./bs_${BOARD_TS}_tests_bsim_bluetooth_audio_prj_conf \
+  -v=${VERBOSITY_LEVEL} -s=${SIMULATION_ID} -d=0 -testid=unicast_client_reconf_group -rs=23 -D=1
+
+# Simulation time should be larger than the WAIT_TIME in common.h
+Execute ./bs_2G4_phy_v1 -v=${VERBOSITY_LEVEL} -s=${SIMULATION_ID} \
+  -D=1 -sim_length=60e6 $@
+
+wait_for_background_jobs