Banknotes do not have to be classed as legal tender to be acceptable for trade; millions of retail transactions are carried out each day in the UK using debit cards and credit cards, none of which is a payment using legal tender. Equally, traders may offer to accept payment in foreign currency, such as euro, yen, or US dollars. Acceptability as a means of payment is essentially a matter for agreement between the parties involved. Where a transaction is subject to VAT, the transaction must be converted to sterling for tax purposes.