If you receive one of the above error codes, it means there is an error in one of your tax numbers. Please check the information you have entered into fields BT-31, BT-32, BT-48 (Buyer VAT identifier) and BT-63. At least one of the following fields must be filled in: BT-31 (Seller VAT identifier), BT-32 (Seller tax registration identifier) or BT-63 (Seller tax representative VAT identifier).