diff --git a/samples/bluetooth/central_and_peripheral_hr/src/main.c b/samples/bluetooth/central_and_peripheral_hr/src/main.c
index 15621a10600..ea1ebd9d2f0 100644
--- a/samples/bluetooth/central_and_peripheral_hr/src/main.c
+++ b/samples/bluetooth/central_and_peripheral_hr/src/main.c
@@ -197,12 +197,11 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
-static const struct bt_conn_auth_cb auth_callbacks = {
-	.cancel = auth_cancel
-};
+static const struct bt_conn_auth_cb auth_callbacks = {.cancel = auth_cancel};
 
 static struct bt_conn_auth_info_cb conn_auth_info_callbacks = {
 	.pairing_complete = pairing_complete,
@@ -294,8 +293,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 
 	if (conn == central_conn) {
diff --git a/samples/bluetooth/central_bas/src/main.c b/samples/bluetooth/central_bas/src/main.c
index a481b1e1f04..84a12d9537a 100644
--- a/samples/bluetooth/central_bas/src/main.c
+++ b/samples/bluetooth/central_bas/src/main.c
@@ -230,8 +230,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 
 	gatt_discover(conn);
@@ -348,10 +348,10 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
-
 static struct bt_conn_auth_cb conn_auth_callbacks = {
 	.cancel = auth_cancel,
 };
diff --git a/samples/bluetooth/central_hids/src/main.c b/samples/bluetooth/central_hids/src/main.c
index 221e8ddbaaa..9d1610bb51d 100644
--- a/samples/bluetooth/central_hids/src/main.c
+++ b/samples/bluetooth/central_hids/src/main.c
@@ -252,8 +252,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 
 	gatt_discover(conn);
@@ -621,7 +621,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
 static struct bt_conn_auth_cb conn_auth_callbacks = {
diff --git a/samples/bluetooth/central_nfc_pairing/src/main.c b/samples/bluetooth/central_nfc_pairing/src/main.c
index 6da49bf415c..1546c5d605b 100644
--- a/samples/bluetooth/central_nfc_pairing/src/main.c
+++ b/samples/bluetooth/central_nfc_pairing/src/main.c
@@ -202,8 +202,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
@@ -325,7 +325,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 
 	k_poll_signal_raise(&pair_signal, 0);
 	bt_le_oob_set_sc_flag(false);
diff --git a/samples/bluetooth/central_smp_client/src/main.c b/samples/bluetooth/central_smp_client/src/main.c
index 5f8ef801931..6f09e6be791 100644
--- a/samples/bluetooth/central_smp_client/src/main.c
+++ b/samples/bluetooth/central_smp_client/src/main.c
@@ -213,8 +213,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
diff --git a/samples/bluetooth/central_uart/src/main.c b/samples/bluetooth/central_uart/src/main.c
index 46a839cc055..3307d6c5e99 100644
--- a/samples/bluetooth/central_uart/src/main.c
+++ b/samples/bluetooth/central_uart/src/main.c
@@ -427,8 +427,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		LOG_INF("Security changed: %s level %u", addr, level);
 	} else {
-		LOG_WRN("Security failed: %s level %u err %d", addr,
-			level, err);
+		LOG_WRN("Security failed: %s level %u err %d %s", addr, level, err,
+			bt_security_err_to_str(err));
 	}
 
 	gatt_discover(conn);
@@ -539,7 +539,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	LOG_WRN("Pairing failed conn: %s, reason %d", addr, reason);
+	LOG_WRN("Pairing failed conn: %s, reason %d %s", addr, reason,
+		bt_security_err_to_str(reason));
 }
 
 static struct bt_conn_auth_cb conn_auth_callbacks = {
diff --git a/samples/bluetooth/fast_pair/input_device/src/main.c b/samples/bluetooth/fast_pair/input_device/src/main.c
index 1739baf689d..fdb47ece5dd 100644
--- a/samples/bluetooth/fast_pair/input_device/src/main.c
+++ b/samples/bluetooth/fast_pair/input_device/src/main.c
@@ -237,7 +237,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_
 	if (!err) {
 		LOG_INF("Security changed: %s level %u", addr, level);
 	} else {
-		LOG_WRN("Security failed: %s level %u err %d", addr, level, err);
+		LOG_WRN("Security failed: %s level %u err %d %s", addr, level, err,
+			bt_security_err_to_str(err));
 	}
 }
 
diff --git a/samples/bluetooth/fast_pair/locator_tag/src/fp_adv.c b/samples/bluetooth/fast_pair/locator_tag/src/fp_adv.c
index 427f7dcb0da..7aeaed7a3b3 100644
--- a/samples/bluetooth/fast_pair/locator_tag/src/fp_adv.c
+++ b/samples/bluetooth/fast_pair/locator_tag/src/fp_adv.c
@@ -392,7 +392,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_
 	if (!err) {
 		LOG_INF("Security changed: %s level %u", addr, level);
 	} else {
-		LOG_WRN("Security failed: %s level %u err %d", addr, level, err);
+		LOG_WRN("Security failed: %s level %u err %d %s", addr, level, err,
+			bt_security_err_to_str(err));
 	}
 }
 
diff --git a/samples/bluetooth/llpm/src/main.c b/samples/bluetooth/llpm/src/main.c
index cb15cd093a0..0257b56917e 100644
--- a/samples/bluetooth/llpm/src/main.c
+++ b/samples/bluetooth/llpm/src/main.c
@@ -392,10 +392,9 @@ static void test_run(void)
 	}
 }
 
-void security_changed(struct bt_conn *conn, bt_security_t level,
-				 enum bt_security_err err)
+void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_security_err err)
 {
-	printk("Security changed: level %i, err: %i\n", level, err);
+	printk("Security changed: level %i, err: %i %s\n", level, err, bt_security_err_to_str(err));
 
 	if (err != 0) {
 		printk("Failed to encrypt link\n");
diff --git a/samples/bluetooth/peripheral_ams_client/src/main.c b/samples/bluetooth/peripheral_ams_client/src/main.c
index 3ee5b6b0816..e3e2fa25af8 100644
--- a/samples/bluetooth/peripheral_ams_client/src/main.c
+++ b/samples/bluetooth/peripheral_ams_client/src/main.c
@@ -306,8 +306,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 			}
 		}
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-		       err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
@@ -343,7 +343,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 
 	bt_conn_disconnect(conn, BT_HCI_ERR_REMOTE_USER_TERM_CONN);
 }
diff --git a/samples/bluetooth/peripheral_ancs_client/src/main.c b/samples/bluetooth/peripheral_ancs_client/src/main.c
index 95e86ca7515..1a69eb9cc78 100644
--- a/samples/bluetooth/peripheral_ancs_client/src/main.c
+++ b/samples/bluetooth/peripheral_ancs_client/src/main.c
@@ -364,8 +364,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 			discover_gattp(conn);
 		}
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-		       err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
@@ -401,7 +401,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 
 	bt_conn_disconnect(conn, BT_HCI_ERR_REMOTE_USER_TERM_CONN);
 }
diff --git a/samples/bluetooth/peripheral_bms/src/main.c b/samples/bluetooth/peripheral_bms/src/main.c
index 6fef3abd5a7..4b00ccec07e 100644
--- a/samples/bluetooth/peripheral_bms/src/main.c
+++ b/samples/bluetooth/peripheral_bms/src/main.c
@@ -77,8 +77,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
@@ -122,7 +122,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
 static struct bt_conn_auth_cb conn_auth_callbacks = {
diff --git a/samples/bluetooth/peripheral_cgms/src/main.c b/samples/bluetooth/peripheral_cgms/src/main.c
index 1ba6d8e70fa..30dda4c2295 100644
--- a/samples/bluetooth/peripheral_cgms/src/main.c
+++ b/samples/bluetooth/peripheral_cgms/src/main.c
@@ -64,8 +64,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
diff --git a/samples/bluetooth/peripheral_cts_client/src/main.c b/samples/bluetooth/peripheral_cts_client/src/main.c
index 0b53dbd4732..dfb9eb6de3a 100644
--- a/samples/bluetooth/peripheral_cts_client/src/main.c
+++ b/samples/bluetooth/peripheral_cts_client/src/main.c
@@ -206,8 +206,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 
 		enable_notifications();
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-		       err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
@@ -243,7 +243,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 
 	bt_conn_disconnect(conn, BT_HCI_ERR_REMOTE_USER_TERM_CONN);
 }
diff --git a/samples/bluetooth/peripheral_gatt_dm/src/main.c b/samples/bluetooth/peripheral_gatt_dm/src/main.c
index 27c1e6579dd..73e9196c929 100644
--- a/samples/bluetooth/peripheral_gatt_dm/src/main.c
+++ b/samples/bluetooth/peripheral_gatt_dm/src/main.c
@@ -109,8 +109,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
@@ -157,7 +157,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 
 	if (pairing_confirmation_conn) {
 		bt_conn_unref(pairing_confirmation_conn);
diff --git a/samples/bluetooth/peripheral_hids_keyboard/src/main.c b/samples/bluetooth/peripheral_hids_keyboard/src/main.c
index 5690e4a1e75..274748549a0 100644
--- a/samples/bluetooth/peripheral_hids_keyboard/src/main.c
+++ b/samples/bluetooth/peripheral_hids_keyboard/src/main.c
@@ -333,12 +333,11 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
-
 BT_CONN_CB_DEFINE(conn_callbacks) = {
 	.connected = connected,
 	.disconnected = disconnected,
@@ -611,10 +610,10 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
-
 static struct bt_conn_auth_cb conn_auth_callbacks = {
 	.passkey_display = auth_passkey_display,
 	.passkey_confirm = auth_passkey_confirm,
diff --git a/samples/bluetooth/peripheral_hids_mouse/src/main.c b/samples/bluetooth/peripheral_hids_mouse/src/main.c
index 245ad4c3220..2a5c4620d2b 100644
--- a/samples/bluetooth/peripheral_hids_mouse/src/main.c
+++ b/samples/bluetooth/peripheral_hids_mouse/src/main.c
@@ -346,13 +346,12 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 #endif
 
-
 BT_CONN_CB_DEFINE(conn_callbacks) = {
 	.connected = connected,
 	.disconnected = disconnected,
@@ -644,10 +643,10 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
-
 static struct bt_conn_auth_cb conn_auth_callbacks = {
 	.passkey_display = auth_passkey_display,
 	.passkey_confirm = auth_passkey_confirm,
diff --git a/samples/bluetooth/peripheral_lbs/src/main.c b/samples/bluetooth/peripheral_lbs/src/main.c
index c7facd1f4df..954eedaa682 100644
--- a/samples/bluetooth/peripheral_lbs/src/main.c
+++ b/samples/bluetooth/peripheral_lbs/src/main.c
@@ -79,8 +79,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 #endif
@@ -127,7 +127,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
 static struct bt_conn_auth_cb conn_auth_callbacks = {
diff --git a/samples/bluetooth/peripheral_mds/src/main.c b/samples/bluetooth/peripheral_mds/src/main.c
index cbf4ec1499e..a486a71d252 100644
--- a/samples/bluetooth/peripheral_mds/src/main.c
+++ b/samples/bluetooth/peripheral_mds/src/main.c
@@ -54,8 +54,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 
 	if (level >= BT_SECURITY_L2) {
@@ -112,7 +112,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 
 	if (pairing_confirmation_conn) {
 		pairing_confirmation_conn = NULL;
diff --git a/samples/bluetooth/peripheral_nfc_pairing/src/main.c b/samples/bluetooth/peripheral_nfc_pairing/src/main.c
index e188c7b74da..3a997009c9e 100644
--- a/samples/bluetooth/peripheral_nfc_pairing/src/main.c
+++ b/samples/bluetooth/peripheral_nfc_pairing/src/main.c
@@ -333,7 +333,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 
 	k_poll_signal_raise(&pair_signal, 0);
 	bt_le_oob_set_sc_flag(false);
@@ -414,8 +415,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
diff --git a/samples/bluetooth/peripheral_power_profiling/src/main.c b/samples/bluetooth/peripheral_power_profiling/src/main.c
index 71d69358f80..0b991304b2a 100644
--- a/samples/bluetooth/peripheral_power_profiling/src/main.c
+++ b/samples/bluetooth/peripheral_power_profiling/src/main.c
@@ -184,8 +184,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 
@@ -332,7 +332,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 
 	/* Generate new pairing keys if pairing procedure failed. */
 	k_work_submit(&key_generate_work);
diff --git a/samples/bluetooth/peripheral_rscs/src/main.c b/samples/bluetooth/peripheral_rscs/src/main.c
index 99de1edb0fa..ca4bd26f5bb 100644
--- a/samples/bluetooth/peripheral_rscs/src/main.c
+++ b/samples/bluetooth/peripheral_rscs/src/main.c
@@ -152,8 +152,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 #endif
@@ -200,7 +200,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
 static struct bt_conn_auth_cb conn_auth_callbacks = {
diff --git a/samples/bluetooth/peripheral_status/src/main.c b/samples/bluetooth/peripheral_status/src/main.c
index fc5d08dcf02..3e8fc2c703b 100644
--- a/samples/bluetooth/peripheral_status/src/main.c
+++ b/samples/bluetooth/peripheral_status/src/main.c
@@ -82,8 +82,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		printk("Security changed: %s level %u\n", addr, level);
 	} else {
-		printk("Security failed: %s level %u err %d\n", addr, level,
-			err);
+		printk("Security failed: %s level %u err %d %s\n", addr, level, err,
+		       bt_security_err_to_str(err));
 	}
 }
 #endif
@@ -130,7 +130,8 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	printk("Pairing failed conn: %s, reason %d\n", addr, reason);
+	printk("Pairing failed conn: %s, reason %d %s\n", addr, reason,
+	       bt_security_err_to_str(reason));
 }
 
 static struct bt_conn_auth_cb conn_auth_callbacks = {
diff --git a/samples/bluetooth/peripheral_uart/src/main.c b/samples/bluetooth/peripheral_uart/src/main.c
index 58f4b13d557..7d47ceb9688 100644
--- a/samples/bluetooth/peripheral_uart/src/main.c
+++ b/samples/bluetooth/peripheral_uart/src/main.c
@@ -381,8 +381,8 @@ static void security_changed(struct bt_conn *conn, bt_security_t level,
 	if (!err) {
 		LOG_INF("Security changed: %s level %u", addr, level);
 	} else {
-		LOG_WRN("Security failed: %s level %u err %d", addr,
-			level, err);
+		LOG_WRN("Security failed: %s level %u err %d %s", addr, level, err,
+			bt_security_err_to_str(err));
 	}
 }
 #endif
@@ -444,10 +444,10 @@ static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
-	LOG_INF("Pairing failed conn: %s, reason %d", addr, reason);
+	LOG_INF("Pairing failed conn: %s, reason %d %s", addr, reason,
+		bt_security_err_to_str(reason));
 }
 
-
 static struct bt_conn_auth_cb conn_auth_callbacks = {
 	.passkey_display = auth_passkey_display,
 	.passkey_confirm = auth_passkey_confirm,
diff --git a/samples/bluetooth/shell_bt_nus/src/main.c b/samples/bluetooth/shell_bt_nus/src/main.c
index 6f5120cbd8d..da16f93e1a8 100644
--- a/samples/bluetooth/shell_bt_nus/src/main.c
+++ b/samples/bluetooth/shell_bt_nus/src/main.c
@@ -76,8 +76,8 @@ static void __attribute__((unused)) security_changed(struct bt_conn *conn,
 	if (!err) {
 		LOG_INF("Security changed: %s level %u", addr, level);
 	} else {
-		LOG_INF("Security failed: %s level %u err %d", addr, level,
-			err);
+		LOG_INF("Security failed: %s level %u err %d %s", addr, level, err,
+			bt_security_err_to_str(err));
 	}
 }
 
@@ -105,7 +105,8 @@ static void pairing_complete(struct bt_conn *conn, bool bonded)
 
 static void pairing_failed(struct bt_conn *conn, enum bt_security_err reason)
 {
-	LOG_INF("Pairing failed conn: %s, reason %d", log_addr(conn), reason);
+	LOG_INF("Pairing failed conn: %s, reason %d %s", log_addr(conn), reason,
+		bt_security_err_to_str(reason));
 }
 
 static struct bt_conn_auth_cb conn_auth_callbacks = {
diff --git a/samples/bluetooth/throughput/src/main.c b/samples/bluetooth/throughput/src/main.c
index 2abaa1a0d1d..59f73458330 100644
--- a/samples/bluetooth/throughput/src/main.c
+++ b/samples/bluetooth/throughput/src/main.c
@@ -213,10 +213,10 @@ static void connected(struct bt_conn *conn, uint8_t hci_err)
 	}
 }
 
-void security_changed(struct bt_conn *conn, bt_security_t level,
-				 enum bt_security_err security_err)
+void security_changed(struct bt_conn *conn, bt_security_t level, enum bt_security_err security_err)
 {
-	printk("Security changed: level %i, err: %i\n", level, security_err);
+	printk("Security changed: level %i, err: %i %s\n", level, security_err,
+	       bt_security_err_to_str(security_err));
 
 	if (security_err != 0) {
 		printk("Failed to encrypt link\n");