We'll create fresh WordPress site with VIES Validator installed. You have 20 minutes to test the plugin after that site we'll be deleted.
The plugin allow you to validate your clients VAT Number using the online VIES service from Agenzia delle Entrate.
If you don’t currently have a VAT Number field you can easily add one from the settings menu. If you already have one just specify the field ID and the validation will take place on your existing field.
For more information about VIES see https://telematici.agenziaentrate.gov.it/VerificaPIVA/Scegli.jsp
Based on eu-vat-validator: a simple and clean PHP library that validates EU VAT registration numbers against the central ec.europa.eu database.