your vat number is built as follow:
9 digits; the last digit is the check digit.
the first digit depends on what the number refers to, e.g.: 1-3 are regular people, 5 are companies.
for companies, it is either 'ES'+letter+8 digits or 'ES'+letter+7 digits+letters.
if your VAT number does not work on our checkout page and for further information, please visit VIES VAT number validation or http://www.vatcheck.eu/