A PIN is a personal identification number used for security purposes.
These are most frequently found on credit and debit cards, and were traditionally used at ATM machines for a user to confirm their identity.
However, since the advent of Chip & Pin, many retailers require cardholders to type their PIN when they make purchases in shops, restaurants and bars.
By the end of 2005 most credit and debit card transactions, where a consumer has been issued with a chip and PIN card and is present during the transaction, will be verified by PIN rather than by signing a paper receipt.
People will be required to use PIN, where possible, from February 2006.