How to add a VAT number field to WooCommerce B2B registration

By Raz Technologies · published 8 Oct 2026 · data updated 2 Nov 2026

How do I add a VAT number field to B2B customer registration in WooCommerce?

Use a B2B registration plugin that adds a VAT number field (6 of the 15 we track document one, 5 also document validating it, 3 explicitly against the EU VIES service) or add the field with three WooCommerce hooks (below) if a format check is enough. As of 2 November 2026, the top-ranked plugin in our B2B registration ranking is EU/UK VAT Validation Manager for WooCommerce (79.0/100). See our B2B registration plugin ranking for the full comparison.

The problem

B2B stores in the EU need a customer's VAT number to sell without VAT under the reverse charge, and often want to check it before approving the account. WooCommerce's registration form has only an email and a password.

Option 1: a plugin (no code)

These ranked B2B registration plugins document a VAT number field (evidence: Documented, from each plugin's readme or listing). Open a profile to see whether the plugin only stores the number or validates it, and the vendor's exact wording.

Need other fields too (company name, tax certificate upload) or approval before first order? 8 plugins we track document extra registration fields (3 in the free version):

Option 2: three hooks (for developers)

This adds an optional VAT number field to the My Account registration form, checks its format (two-letter country prefix plus 2–13 characters) and saves it on the customer. It does not check the number with VIES.

// 1. Show the field
add_action( 'woocommerce_register_form', function () { ?>
    <p class="form-row form-row-wide">
        <label for="reg_vat_number"><?php esc_html_e( 'VAT number', 'my-store' ); ?></label>
        <input type="text" class="input-text" name="vat_number" id="reg_vat_number"
            value="<?php echo esc_attr( wp_unslash( $_POST['vat_number'] ?? '' ) ); ?>" />
    </p>
<?php } );

// 2. Check the format
add_filter( 'woocommerce_registration_errors', function ( $errors ) {
    $vat = strtoupper( preg_replace( '/[^A-Za-z0-9]/', '', wp_unslash( $_POST['vat_number'] ?? '' ) ) );
    if ( '' !== $vat && ! preg_match( '/^[A-Z]{2}[A-Z0-9]{2,13}$/', $vat ) ) {
        $errors->add( 'vat_number', __( 'Enter the VAT number with its country prefix, e.g. DE123456789.', 'my-store' ) );
    }
    return $errors;
} );

// 3. Save it on the new customer
add_action( 'woocommerce_created_customer', function ( $customer_id ) {
    $vat = strtoupper( preg_replace( '/[^A-Za-z0-9]/', '', wp_unslash( $_POST['vat_number'] ?? '' ) ) );
    if ( '' !== $vat ) {
        update_user_meta( $customer_id, 'vat_number', sanitize_text_field( $vat ) );
    }
} );

Make sure "Allow customers to create an account on the My account page" is on (WooCommerce → Settings → Accounts & Privacy), then register a test account.

What to check before you choose

• VIES validation, and what happens when the VIES service is down.
• Whether a valid VAT number removes VAT at checkout (reverse charge) or is only stored.
• A separate B2B form, so retail customers keep the short form.

Other plugins people ask about

• Wholesale Suite is not part of our B2B registration ranking; we rank it #2 of 15 in wholesale pricing, #1 of 5 in all-in-one B2B (as of 2 November 2026).

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