How to return the the invoice to the italian seller
While preparing for Vat refund the buyer must send back the original invoice that is endorsed by the Customs office within four months from the date of issue after having left the Community territory.
If the seller fails to get the invoice in time then he will be fully liable against the state for reimbursement of the Vat deducted earlier from the purchased made by the EU non-resident traveller.
The invoice should include the Vat number of the customer for the goods or services, if he or she is elligible for tax at the location of the supplier and must quote the applicable regulation (Article 21(2)(f) ot Presidential Decree 633/1972).
The merchant will issue you a separate receipt along with the cash receipt in the case of Vat is not being taken off the price & returned back to the buyer before making payment for goods. This type of receipt is known as “fattura,” and it contains buyer’s name (so keep that passport handy) and the amount of the IVA (VAT) tax for that purchase. The buyer should preserve all forms and receipts, including the additional “fattura” receipts, in a safe and sound place.
You must show all your receipts and the purchased goods for inspection and they’ll get stamped by custom office. You then have to send those stamped receipts back to the seller from whom you purchased the items in the beginning.
Many larger merchants deal with companies like Global Refund & Premier Tax Free that have branches at airports and other international gateways in Italy. In order to get a Vat reclaim you have to bring the stamped receipts with you to the appropriate agency’s office in the airport. You may receive a cash refund instantly, or they’ll refund your credit card. In this purpose they may charge a small percentage of the total amount.
If the merchants are not accustomed with the above system then you should have to mail your receipts back to them directly before leaving the country either from the airport or from home. It is quite risky as it could happen that you never got a refund or hear from the merchant again. If you still get a refund that may come with a cheque in euros that should be charged with a fee from your local bank to convert it into dollars.