The Bank of England warns that 460 million banknotes will soon become invalid

Old paper £20 and £50 notes may no longer be issued from September 30, the Bank of England has warned. That means you have 100 days to search your piggy banks for forgotten cash

Brits are being urged to check pots of money and piggy banks at home as there are just 100 days left to either spend or cash in £20 and £50 notes.

The old money has been replaced with more durable plastic cash, but the Bank of England estimates there are still more than £6 billion worth of £20 notes tucked away in wallets, piggy banks and even old trouser pockets.

And there are believed to be a staggering £8 billion worth of old £50 notes in circulation.

It has been a year since the bank first issued the polymeric £50 note featuring the Bletchley Park codebreaker and scientist Alan Turing to support the revision of the £5, £10, £20 pound and 50 pound notes.

His image replaced entrepreneur Matthew Boulton and engineer James Watt, while new £20 artist JMW Turner replaced economist Adam Smith in 2020.

Do you still have old paper bills in your piggy bank? Let us know in the comments below

Both banknotes will cease to be legal tender on September 30, the Bank of England said. After this date, you will no longer be able to spend them in stores.

The Bank of England encourages those who still have these to use them or have them deposited at your bank or post office within the last 100 days.

People can also hand in old banknotes to the bank on Threadneedle Street in the City of London to be deposited into a bank account by check or exchanged for novelty polymer banknotes if you have less than £50 to exchange.

Chief Cashier Sarah John said: “The switch from paper to polymer banknotes in recent years has been an important development as it makes them more difficult to counterfeit and more durable.

“The majority of paper banknotes have now been phased out but a significant number remain in the economy so we urge you to check you have any at home.

“These can still be used for the next 100 days or deposited with your bank as normal.”

It is believed that more than 300 million individual £20 notes and 160 million paper £50 notes are still in circulation.

Former Bank of England Governor Mark Carney, who spearheaded their introduction, said: “Polymer notes are more secure than paper notes and last more than twice as long.”

However, the polymer banknotes are not without problems.

Some bills can accidentally shrink to a quarter of their size when ironed in a pocket.