Is possible to modify user_login after registration?
WordPress does not allow updating user_login for existing users. You may update it using $wpdb->update as below: // Sanitizes the username $user_login = sanitize_user( trim( $user_login ), true ); // Check if the given username exists if ( ! empty( $user_login ) && ! username_exists( $user_login ) ) { global $wpdb; //Update user record $wpdb->update( … Read more