The VAT Information Exchange System (VIES) is an electronic means of transmitting information relating to VAT registration (i.e., validity of VAT numbers) of companies registered in the European Union. EU law requires that, where goods or services are procured within the EU, VAT must be paid only in the member state where the purchaser resides. For this reason, suppliers need an easy way to validate the VAT numbers presented by purchasers. This validation is performed through VIES.
VIES does not itself maintain a VAT number database. Instead, it forwards the VAT number validation query to the database of the member state concerned and, upon reply, it transmits back to the inquirer the information provided by the member state. This information includes at least a "YES/NO" answer on the existence and validity of the supplied number. It may also include additional information, such as the holder's name and address, if this is provided by the member state.
VIES optionally provides a unique reference number which can be used to prove to a tax authority that a particular VAT number was confirmed at time of purchase.
Germany, Italy and Spain provide similar services at national level.