A new free nBill extension has been released for checking whether EU VAT numbers are valid. This extension works on both the standard edition and the Lite edition of nBill (Lite edition affects client profile only, standard edition can be used on order forms and quote request forms as well). The extension offers a list of EU member states for the client to select from, followed by a free format text box for the rest of their VAT number. The number entered is checked against the VIES database to make sure it is a valid, registered VAT number. It does not
verify that the number belongs to the company name/address, only that it is a valid number. For more information see the 'About' section after installing the extension.
It is an nBill extension, NOT a Joomla extension, so you must use the nBill extension installer to install it. You can download it here: http://www.nbill.co.uk/component/option,com_docman/Itemid,0/task,cat_view/gid,14/