---
title: "VIES VAT Validation Blocked (IP_BLOCKED): Alternative VAT Validation in WooCommerce"
description: "VIES blocked your server IP (IP_BLOCKED)? Route EU VAT validation through a third-party API or use the built-in VATSense option."
url: "https://wpfactory.com/docs/vies-ip-blocking/"
updated: "2026-09-26"
category: Troubleshooting
---

# VIES VAT Validation Blocked (IP_BLOCKED): Alternative VAT Validation in WooCommerce

## VIES IP blocking and alternative VAT validation

If your VAT validation log shows IP_BLOCKED, the VIES service has blocked your server's IP, so EU/UK VAT Manager for WooCommerce cannot reach it. The workaround is to route validation through a third-party API, such as Vatlayer, with a code snippet that uses the alg_wc_eu_vat_validation_response filter, added with a plugin like Code Snippets.

### The symptom

VIES (VAT Information Exchange System), run by the European Commission, is the primary service for validating EU VAT numbers. When a server IP is blocked, validation returns failed or unknown responses and your log shows `IP_BLOCKED`.

![IP_BLOCKED entry in the EU VAT validation log](https://wpfactory.com/wp-content/uploads/IP_Blocked.png)

The European Commission does not publish the exact criteria, but blocks often affect shared hosting or servers making high request volumes. Moving to a new host or IP can fix it but is usually impractical.

### Workaround: route validation through a third-party API

The plugin exposes the `alg_wc_eu_vat_validation_response` filter, which lets you replace the validation response with one from another service. The example below uses Vatlayer, which offers a free tier.

#### Step 1: install a snippet manager

Add the code with a plugin such as [Code Snippets](https://wordpress.org/plugins/code-snippets/) so you do not edit your theme's `functions.php`.

#### Step 2: add the snippet

Create a new snippet and paste the code below. Replace the placeholder key with your own Vatlayer API key.

```
add_filter(
	'alg_wc_eu_vat_validation_response',
	function ( $response, $method, $country_code, $vat_number ) {
		$key = 'YOUR_KEY_HERE'; // set your Vatlayer key
		$url = "https://apilayer.net/api/validate?access_key={$key}&vat_number={$country_code}{$vat_number}";
		$curl = curl_init( $url );
		curl_setopt( $curl, CURLOPT_RETURNTRANSFER, 1 );
		curl_setopt( $curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4 );
		$res = curl_exec( $curl );
		curl_close( $curl );
		if ( $res ) {
			$res = json_decode( $res, true );
			$response = json_encode( array(
				'isValid'   => $res['valid'],
				'name'      => $res['company_name'],
				'address'   => $res['company_address'],
				'vatNumber' => $res['vat_number'],
			) );
		}
		return $response;
	},
	10,
	4
);
```

#### Step 3: test

With the snippet active and your key in place, run a test validation on the checkout or in the plugin settings and confirm the number now validates.

### Built-in alternative: VATSense

For UK, Australian, Norwegian and Swiss numbers, the plugin already integrates VATSense. You can also enable **Enable VATSense fallback** on the **Validation** sub-tab (a VATSense API key is required) so VATSense is used when VIES is unavailable. See [VATSense validation for UK and non-EU numbers](https://wpfactory.com/docs/eu-vat-for-woocommerce/).

### Need a hand?

Our team answers every ticket on the [EU/UK VAT Manager support forum](https://wpfactory.com/support/item/eu-vat-for-woocommerce/).

Related articles

- [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/)
- [Customize the VAT Validation Messages](https://wpfactory.com/docs/customize-vat-validation-messages/)
- [EU VAT Validation Options in WooCommerce](https://wpfactory.com/docs/streamline-eu-vat/)
- [Configuring EU VAT Validation](https://wpfactory.com/docs/configure-eu-vat-validation/)