Restrict Content Pro Avatax - Allow users to disable Avatax address validation before submitting the address.

Disable-Address-Validation-Filters.php

<?php

// Disable for all registrations
add_filter( 'rcp_avatax_disable_validate_address', '__return_true' );

// Selectively disable address validation example by state/province
add_filter( 'rcp_avatax_disable_validate_address', function ( $disable, $post ) {

	$state = isset( $post['rcp_card_state'] ) ? $post['rcp_card_state'] : '';

	if ( 'QC' === $state ) {
		$disable = true;
	}

	return $disable;
}, 10, 2 );