diff --git a/drivers/espi/host_subs_npcx.c b/drivers/espi/host_subs_npcx.c
index 63d96fb336e..875e5b32959 100644
--- a/drivers/espi/host_subs_npcx.c
+++ b/drivers/espi/host_subs_npcx.c
@@ -235,9 +235,8 @@ static void host_kbc_ibf_isr(void *arg)
 	 * The high byte contains information from the host, and the lower byte
 	 * indicates if the host sent a command or data. 1 = Command.
 	 */
-	evt.evt_data = (inst_kbc->HIKMDI << NPCX_8042_DATA_POS) |
-		       (IS_BIT_SET(inst_kbc->HIKMST, NPCX_HIKMST_A2) <<
-				       NPCX_8042_TYPE_POS);
+	evt.evt_data = NPCX_8042_EVT_DATA(NPCX_8042_EVT_IBF, inst_kbc->HIKMDI,
+			IS_BIT_SET(inst_kbc->HIKMST, NPCX_HIKMST_A2));
 
 	LOG_DBG("%s: kbc data 0x%02x", __func__, evt.evt_data);
 	espi_send_callbacks(host_sub_data.callbacks, host_sub_data.host_bus_dev,
@@ -248,6 +247,9 @@ static void host_kbc_obe_isr(void *arg)
 {
 	ARG_UNUSED(arg);
 	struct kbc_reg *const inst_kbc = host_sub_cfg.inst_kbc;
+	struct espi_event evt = { ESPI_BUS_PERIPHERAL_NOTIFICATION,
+		ESPI_PERIPHERAL_8042_KBC, ESPI_PERIPHERAL_NODATA
+	};
 
 	/* Disable KBC OBE interrupt first */
 	inst_kbc->HICTRL &= ~BIT(NPCX_HICTRL_OBECIE);
@@ -255,11 +257,13 @@ static void host_kbc_obe_isr(void *arg)
 	LOG_DBG("%s: kbc status 0x%02x", __func__, inst_kbc->HIKMST);
 
 	/*
-	 * TODO: Notify application that host already read out data. We might
-	 * use E8042_SET_FLAG in espi_api_lpc_write_request() instead of setting
-	 * status of HIKMST here directly.
+	 * Notify application that host already read out data. The application
+	 * might need to clear status register via espi_api_lpc_write_request()
+	 * with E8042_CLEAR_FLAG opcode in callback.
 	 */
-	inst_kbc->HIKMST &= ~BIT(NPCX_HIKMST_ST1);
+	evt.evt_data = NPCX_8042_EVT_DATA(NPCX_8042_EVT_OBE, 0, 0);
+	espi_send_callbacks(host_sub_data.callbacks, host_sub_data.host_bus_dev,
+							evt);
 }
 
 static void host_kbc_init(void)
diff --git a/soc/arm/nuvoton_npcx/common/soc_espi.h b/soc/arm/nuvoton_npcx/common/soc_espi.h
index 54a8894e30a..97d32cadd35 100644
--- a/soc/arm/nuvoton_npcx/common/soc_espi.h
+++ b/soc/arm/nuvoton_npcx/common/soc_espi.h
@@ -12,9 +12,23 @@ extern "C" {
 #endif
 
 /* 8042 event data format */
+#define NPCX_8042_EVT_POS 16U
 #define NPCX_8042_DATA_POS 8U
 #define NPCX_8042_TYPE_POS 0U
 
+/* 8042 event type format */
+#define NPCX_8042_EVT_IBF BIT(0)
+#define NPCX_8042_EVT_OBE BIT(1)
+
+/*
+ * The format of event data for KBC 8042 protocol:
+ * [23:16] - 8042 event type: 1: Input buffer full, 2: Output buffer empty.
+ * [15:8]  - 8042 data: 8-bit 8042 data.
+ * [0:7]   - 8042 protocol type: 0: data type, 1: command type.
+ */
+#define NPCX_8042_EVT_DATA(event, data, type) (((event) << NPCX_8042_EVT_POS) \
+	| ((data) << NPCX_8042_DATA_POS) | ((type) << NPCX_8042_TYPE_POS));
+
 /* ACPI event data format */
 #define NPCX_ACPI_DATA_POS 8U
 #define NPCX_ACPI_TYPE_POS 0U