ArrayGator

Google’s Product rich-results guidelines require that the price in your product schema match the price shown to users. 
When WooCommerce is set to “Prices entered excluding tax” this isn’t the case—schema shows the net figure while the shop shows the gross.
Price Schema VAT Fixer plugs that gap:
<ul>
<li>Overrides the WooCommerce structured-data filter (<code>woocommerce_structured_data_product</code>) and injects the correct gross price.</li>
<li>Lets you define a tax-lookup address distinct from the store base location when your shop’s physical location differs from the VAT regime you charge.</li>
<li>No templates touched, no extra database tables.</li>
</ul>
Built for merchants who care about SEO, compliance, and clarity.

Price Schema VAT Fixer

Fixes WooCommerce JSON-LD so product schema shows the same VAT-inclusive price shoppers see.

marekma

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 <a href="https://telematici.agenziaentrate.gov.it/VerificaPIVA/Scegli.jsp" rel="nofollow ugc">https://telematici.agenziaentrate.gov.it/VerificaPIVA/Scegli.jsp</a>
Based on <a href="https://github.com/pH-7/eu-vat-validator" rel="nofollow ugc">eu-vat-validator</a>: a simple and clean PHP library that validates EU VAT registration numbers against the central ec.europa.eu database.

VIES Validator

Add a VAT Number (Partita IVA) field to Woocommerce checkout and validate it using the VIES API service from Agenzia delle Entrate.

Price Schema VAT Fixer vs VIES Validator