More than £9 billion in old bank notes and coins have not been cashed in.
Although £20 and £50 notes stopped being legal tender last October 445 million are still in circulation.
The Bank of England (BOE) said there was also £87 million of old £1 coins kicking around.
In a breakdown of sums the BoE said there were 111 million £5 notes, 65 million £10, 198 million £20 and 70 million £50 notes not returned.
Paper £5 notes were withdrawn six years ago.
While all the paper notes are no longer legal tender, a Bank of England spokeswoman said “all genuine” banknotes that have been withdrawn from circulation keep their face value.
They can be returned to banks and some Post Offices.
