---
title: Site Crashes When the VAT Plugin Is Active
description: WooCommerce site crashing only when the EU VAT plugin is active? Steps to restore access and find the cause.
url: "https://wpfactory.com/docs/title-site-crashes-when-vat-validation-plugin-is-active-slug/"
updated: "2026-09-27"
category: Troubleshooting
tags:
  - EU VAT Manager for WooCommerce
---

# Site Crashes When the VAT Plugin Is Active

If your site crashes with a fatal or memory error only while EU/UK VAT Manager for WooCommerce is active, the cause is almost always a plugin or theme conflict or a low PHP memory limit. Deactivate the plugin to restore access, update everything, raise the memory limit, and then test for conflicts with a default theme.

### Symptoms

- PHP fatal error such as "Allowed memory size of ... bytes exhausted" when the plugin is active.
- The site works normally as soon as the plugin is deactivated.

### Cause

This is almost always a conflict with another plugin or theme (commonly a multi-language plugin, custom checkout, or page builder) or a very low PHP memory limit on the host, rather than the VAT plugin alone.

### Fix

1. **Restore access.** Deactivate the plugin from WP admin, or rename its folder over FTP if the dashboard is unreachable.
2. **Update everything.** Update the plugin, WordPress and WooCommerce to their latest versions.
3. **Raise the PHP memory limit** temporarily, for example add `define('WP_MEMORY_LIMIT','256M');` to `wp-config.php`, then re-test.
4. **Test for conflicts.** Switch to a default theme and disable other plugins, then reactivate the VAT plugin. Re-enable the others one at a time to find the culprit.
5. **Collect details.** If it still crashes, turn on `WP_DEBUG`, capture the file and function in the error, and send it to support with your PHP version, memory limit and active plugin list.

### Prerequisites

- Access to WP admin, FTP, or your hosting control panel.
- Ability to edit PHP settings on your host.

### Need a hand?

Test plugin updates on a staging site first, then reach the team on the [EU/UK VAT Manager support forum](https://wpfactory.com/support/item/eu-vat-for-woocommerce/) with your debug log.

Related articles

- [VAT Not Removed After Entering a Valid VAT Number](https://wpfactory.com/docs/eu-vat-not-removed-valid-number/)
- [VAT Field Not Showing in Block-Based Checkout](https://wpfactory.com/docs/vat-field-block-checkout-issue/)
- [EU VAT Validation Always Fails](https://wpfactory.com/docs/eu-vat-validation-fails/)
- [UK VAT Validation Fails](https://wpfactory.com/docs/uk-vat-validation-fails/)
- [VIES VAT Validation Blocked (IP_BLOCKED): Alternative VAT Validation in WooCommerce](https://wpfactory.com/docs/vies-ip-blocking/)

 

[![EU VAT Manager for WooCommerce](https://wpfactory.com/wp-content/uploads/EU-UK-VAT-Manager-for-WooCommerce.webp)](https://wpfactory.com/item/eu-vat-for-woocommerce/)