At moment of purchase, request for a Customs Tax Invoice. Please note only shops with a licence to sell to military staff are able to provide you with this type of invoice. Your station can provide you a list of shops licensed. Furthermore, only items with a minimum purchase amount of €46 (including VAT) can be listed on the CTI for a VAT refund.
Visit the office at your military base to get a stamp on the Customs Tax Invoice for approval;
(*) Please make sure to upload a copy of the front and back of your NATO ID
(**) When registering your receipt under the receipt page, make sure to upload the copy/scan of your receipt AND Customs Tax Invoice