The pound sterling (symbol: £; ISO code: GBP), commonly known simply as the pound, is the official currency of the United Kingdom, Jersey, Guernsey, the Isle of Man, South Georgia and the South Sandwich Islands, the British Antarctic Territory, and Tristan da Cunha. A number of nations that do not use sterling also have currencies called the pound. At various times, the pound sterling was commodity money or bank notes backed by silver or gold, but it is currently fiat money, backed only by the economy in the areas where it is accepted. The pound sterling is the world's oldest currency still in use and which has been in continuous usage since its inception.