Sterling banknote

Sterling banknotes are the banknotes in circulation in the United Kingdom and its related territories. They are issued in various denominations of pounds sterling (symbol: £ or GBP).
Sterling banknotes are official currency in the United Kingdom, Jersey, Guernsey, the Isle of Man, South Georgia and the South Sandwich Islands, and Tristan da Cunha. One pound is equivalent to 100 pence. Three British Overseas Territories also have currencies called pounds which are at par with (worth equal to) the pound sterling.
Banknotes are issued by the Bank of England, and also by seven other banks in the United Kingdom. Only the Bank of England notes are legal currency, meaning they "must" be accepted in retail tade, restaurants and so on. 
The other banks, mostly in Scotland and Northern Ireland issue notes which are always accepted in their countries. In London, where many people are of foreign origin, these notes may be refused in some places.