There are just over three weeks left to use paper £20 and £50 notes before the Bank of England withdraws them for good.

After September 30 the old-style paper notes won't be accepted by shops or businesses as legal tender and so people are being encouraged to spend or deposit them as soon as possible.

Millions of the old-style notes are still thought to remain in circulation - many tucked away in people's homes, pockets and piggy banks where they've been forgotten about.

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.

The old 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.

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.

What happens after September 30?

After September 30 anyone who finds a forgotten paper note and has a UK bank account will be able to ask to deposit it at their branch.

Some Post Office branches may also still choose to accept the withdrawn notes as a deposit to any bank account you can access with them.

The Bank of England will always exchange any withdrawn notes, and this includes paper notes that have been taken out of circulation in the past. However this is most usually done through the post and so that exchange is done at someone's own risk.

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."