In countries where wire transfer is the preferred method of settling debts, the printed bill will contain the bank account number of the creditor and usually a reference code to be passed along with the transaction identifying the payer. The US Defense Logistics Agency requires an employer identification number on invoices. The European Union requires a VAT (value-added tax) identification number for official VAT invoices, which all VAT-registered businesses are required to issue to their customers. In the UK, this number may be omitted on invoices if the words "this is not a VAT invoice" are present on the invoice. Such an invoice is called a pro-forma invoice, and is not an adequate substitute for a full VAT invoice for VAT-registered customers. In Canada, the registration number for GST purposes must be furnished for all supplies over $30 made by a registered supplier in order to claim input tax credits. Recommendations about invoices used in international trade are also provided by the UNECE Committee on Trade, which involves a more detailed description of the logistics aspect of merchandise and, therefore may be convenient for international logistics and customs procedures. European Union EU VAT union invoice definition Within the European Union Value Added Tax directive, Article 226 gives a concise definition of invoices within the European Union's member-states. Without prejudice to the particular provisions laid down in this Directive, only the following details are required for VAT purposes on invoices issued pursuant to Articles 220 and 221: the date of issue; a sequential number, based on one or more series, which uniquely identifies the invoice; the VAT identification number referred to in Article 214 under which the taxable person supplied the goods or services; the customer's VAT identification number, as referred to in Article 214, under which the customer received a supply of goods or services in respect of which he is liable for payment of VAT, or received a supply of goods as referred to in Article 138; the full name and address of the taxable person and of the customer; the quantity and nature of the goods supplied or the extent and nature of the services rendered; the date on which the supply of goods or services was made or completed or the date on which the payment on account referred to in points (4) and (5) of Article 220 was made, in so far as that date can