The official London website notes that the official currency in the United Kingdom is the pound sterling. The pound is denoted by Great British Pound (GBP). One GBP is equal to 100 pence. Paper bills come in denominations of 5, 10, 20 and 50 GBP.
The London website also notes that coins come in denominations of 1p, 2p, 5p, 10p, 20p, 50p, 1 GBP and 2 GBP. Colloquially, 1 GBP is called a "quid" while 5 GBP is called a "fiver" and a ten pound bill is known as a "tenner." Go Currency notes that the British pound is one of the most highly traded currencies in the world.