Households could be facing a race against time to get rid of old paper bank notes which won't be accepted by shops after this summer.

Millions of the old-style paper £20 and £50 notes remain in circulation but the Bank of England is withdrawing them later this year in favour of those with a more plastic-like feel which are harder to copy.

With just six months to go until the paper notes won't any longer be valid on the high street and accepted as legal tender, people are being encouraged to spend or deposit them as soon as possible.

When the plans were first announced last October there were estimated to be around £9 billion worth of paper £20 and £15 billion worth of paper £50 notes still in circulation.

Notes are being returned steadily to the Bank of England as they are replaced with the new polymer notes, which allow for more security features that make them harder to counterfeit.

But with six months to go until the September 30 deadline millions of the paper notes still reportedly remain in circulation, potentially tucked away in people's homes, pockets or piggy banks where they have been forgotten about and risk only being discovered once the cut-off point to spend them has passed.

The new £20 notes, first issued in February 2020, feature Margate's JMW Turner, and the £50 notes, which arrived in June last year, a picture of mathematician and scientist Alan Turing.

Alongside being harder to fake, the new style notes are also resistant to dirt and moisture so they should remain in a better condition for longer despite the amount of time they pass between different hands.

After September 30 the notes won't any longer be accepted by shops and businesses.

However, people with a UK bank account will still be able to deposit any withdrawn notes into their account.

And some Post Office branches may still choose to accept the withdrawn notes as payments for its services.

Bank of England chief cashier Sarah John said: “In recent years we have been changing our banknotes from paper to polymer because this makes them more difficult to counterfeit, and means they are more durable.

"The polymer £20 featuring the artist J.M.W. Turner, and the polymer £50 featuring the scientist Alan Turing are now in wide circulation, and we are in the process of withdrawing their paper equivalents."