diff --git a/changelog/fix-remove-unused-file b/changelog/fix-remove-unused-file
new file mode 100644
index 00000000000..fb464b062ca
--- /dev/null
+++ b/changelog/fix-remove-unused-file
@@ -0,0 +1,5 @@
+Significance: patch
+Type: dev
+Comment: Removed unused file.
+
+
diff --git a/includes/admin/class-wc-rest-user-exists-controller.php b/includes/admin/class-wc-rest-user-exists-controller.php
deleted file mode 100644
index bd9d1eeb6aa..00000000000
--- a/includes/admin/class-wc-rest-user-exists-controller.php
+++ /dev/null
@@ -1,89 +0,0 @@
-<?php
-/**
- * Class WC_REST_User_Exists_Controller
- *
- * @package WooCommerce\Payments\Admin
- *
- *
- * NOTE: This API endpoint is never registered and not available for use.
- * It is only available here as a temporary workaround for the issue described in
- * https://github.com/Automattic/woocommerce-payments/issues/6304
- *
- * This file can be removed once the issue is resolved.
- */
-
-defined( 'ABSPATH' ) || exit;
-
-/**
- * REST controller to check if a user exists.
- */
-class WC_REST_User_Exists_Controller extends WP_REST_Controller {
-
-	/**
-	 * Endpoint namespace.
-	 *
-	 * @var string
-	 */
-	protected $namespace = 'wc/v3';
-
-	/**
-	 * Endpoint path.
-	 *
-	 * @var string
-	 */
-	protected $rest_base = 'users/exists';
-
-	/**
-	 * Configure REST API routes.
-	 */
-	public function register_routes() {
-		register_rest_route(
-			$this->namespace,
-			'/' . $this->rest_base,
-			// Silence the nosemgrep audit rule because this controller (and its routes) is not being used.
-			// This file is only left to avoid plugin upgrade errors.
-			// See this issue for a permanent fix: https://github.com/Automattic/woocommerce-payments/issues/6304
-			// nosemgrep: audit.php.wp.security.rest-route.permission-callback.return-true -- reason: this controller is not being used.
-			[
-				'methods'             => WP_REST_Server::CREATABLE,
-				'callback'            => [ $this, 'user_exists' ],
-				'permission_callback' => '__return_true',
-				'args'                => [
-					'email' => [
-						'required'    => true,
-						'description' => __( 'Email address.', 'woocommerce-payments' ),
-						'type'        => 'string',
-						'format'      => 'email',
-					],
-				],
-			]
-		);
-	}
-
-	/**
-	 * Retrieve if a user exists by email address.
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 *
-	 * @return WP_REST_Response
-	 */
-	public function user_exists( WP_REST_Request $request ): WP_REST_Response {
-		$email        = $request->get_param( 'email' );
-		$email_exists = ! empty( email_exists( $email ) );
-		$message      = null;
-
-		if ( $email_exists ) {
-			// Use this function to show the core error message.
-			$error   = wc_create_new_customer( $email );
-			$message = $error->get_error_message();
-		}
-
-		return new WP_REST_Response(
-			[
-				'user-exists' => $email_exists,
-				'message'     => $message,
-			]
-		);
-	}
-}
-