I need to show in admin user profile

Hi Ruth,
If you are referring to the Admin > Users > Your Profile page, adding the VAT number to it should be simple enough. Here’s a filter that should do the trick.

add_filter('woocommerce_customer_meta_fields', function($fields) {
  $fields['billing']['fields']['vat_number'] = array(
    'label' => __( 'VAT Number', 'woocommerce' ),
    'description' => '',
  );
  return $fields;
}, 10, 1);

I will take note this for a future update of the EU VAT Assistant. It could be convenient to have such field in the User Profile page, out of the box.

Note
The VAT number in the User Profile page won’t validated by the EU VAT Assistant. This is because the validation occurs at checkout, using the billing country at the moment of purchase.

Hi Ruth,
As anticipated, we added the feature you requested to the EU VAT Assistant 1.7.17.180106, due to be released today. Once that version becomes available, you will no longer need to use the custom filter I sent you. ??

That’s great thank you