diff --git a/ports/nrf/common-hal/_bleio/Characteristic.c b/ports/nrf/common-hal/_bleio/Characteristic.c
index 57c4814489..c0f0372c3f 100644
--- a/ports/nrf/common-hal/_bleio/Characteristic.c
+++ b/ports/nrf/common-hal/_bleio/Characteristic.c
@@ -132,13 +132,6 @@ size_t common_hal_bleio_characteristic_get_value(bleio_characteristic_obj_t *sel
 }
 
 void common_hal_bleio_characteristic_set_value(bleio_characteristic_obj_t *self, mp_buffer_info_t *bufinfo) {
-    if (self->fixed_length && bufinfo->len != self->max_length) {
-        mp_raise_ValueError(translate("Value length != required fixed length"));
-    }
-    if (bufinfo->len > self->max_length) {
-        mp_raise_ValueError(translate("Value length > max_length"));
-    }
-
     // Do GATT operations only if this characteristic has been added to a registered service.
     if (self->handle != BLE_GATT_HANDLE_INVALID) {
 
@@ -148,6 +141,14 @@ void common_hal_bleio_characteristic_set_value(bleio_characteristic_obj_t *self,
             common_hal_bleio_gattc_write(self->handle, conn_handle, bufinfo,
                                          (self->props & CHAR_PROP_WRITE_NO_RESPONSE));
         } else {
+            // Validate data length for local characteristics only.
+            if (self->fixed_length && bufinfo->len != self->max_length) {
+                mp_raise_ValueError(translate("Value length != required fixed length"));
+            }
+            if (bufinfo->len > self->max_length) {
+                mp_raise_ValueError(translate("Value length > max_length"));
+            }
+
             // Always write the value locally even if no connections are active.
             // conn_handle is ignored for non-system attributes, so we use BLE_CONN_HANDLE_INVALID.
             common_hal_bleio_gatts_write(self->handle, BLE_CONN_HANDLE_INVALID, bufinfo);
diff --git a/ports/nrf/common-hal/_bleio/Connection.c b/ports/nrf/common-hal/_bleio/Connection.c
index 4f747bf976..36fda0bb35 100644
--- a/ports/nrf/common-hal/_bleio/Connection.c
+++ b/ports/nrf/common-hal/_bleio/Connection.c
@@ -522,7 +522,7 @@ STATIC void on_char_discovery_rsp(ble_gattc_evt_char_disc_rsp_t *response, bleio
         common_hal_bleio_characteristic_construct(
             characteristic, m_char_discovery_service, gattc_char->handle_value, uuid,
             props, SECURITY_MODE_OPEN, SECURITY_MODE_OPEN,
-            GATT_MAX_DATA_LENGTH, false,   // max_length, fixed_length: values may not matter for gattc
+            GATT_MAX_DATA_LENGTH, false,   // max_length, fixed_length: values don't matter for gattc
             mp_const_empty_bytes);
 
         mp_obj_list_append(MP_OBJ_FROM_PTR(m_char_discovery_service->characteristic_list),
diff --git a/ports/nrf/common-hal/_bleio/Descriptor.c b/ports/nrf/common-hal/_bleio/Descriptor.c
index 9e91107231..d848659fce 100644
--- a/ports/nrf/common-hal/_bleio/Descriptor.c
+++ b/ports/nrf/common-hal/_bleio/Descriptor.c
@@ -73,13 +73,6 @@ size_t common_hal_bleio_descriptor_get_value(bleio_descriptor_obj_t *self, uint8
 }
 
 void common_hal_bleio_descriptor_set_value(bleio_descriptor_obj_t *self, mp_buffer_info_t *bufinfo) {
-    if (self->fixed_length && bufinfo->len != self->max_length) {
-        mp_raise_ValueError(translate("Value length != required fixed length"));
-    }
-    if (bufinfo->len > self->max_length) {
-        mp_raise_ValueError(translate("Value length > max_length"));
-    }
-
     // Do GATT operations only if this descriptor has been registered.
     if (self->handle != BLE_GATT_HANDLE_INVALID) {
         uint16_t conn_handle = bleio_connection_get_conn_handle(self->characteristic->service->connection);
@@ -87,6 +80,14 @@ void common_hal_bleio_descriptor_set_value(bleio_descriptor_obj_t *self, mp_buff
             // false means WRITE_REQ, not write-no-response
             common_hal_bleio_gattc_write(self->handle, conn_handle, bufinfo, false);
         } else {
+            // Validate data length for local descriptors only.
+            if (self->fixed_length && bufinfo->len != self->max_length) {
+                mp_raise_ValueError(translate("Value length != required fixed length"));
+            }
+            if (bufinfo->len > self->max_length) {
+                mp_raise_ValueError(translate("Value length > max_length"));
+            }
+
             common_hal_bleio_gatts_write(self->handle, conn_handle, bufinfo);
         }
     }