UK Post Offices are expecting a "last moment" influx of customers depositing paper £20 and £50 banknotes this week before they can no longer be used in shops.

Friday 30 September is the deadline that the Bank of England's paper notes will have legal tender status.

After that date, only polymer banknotes will be acceptable in shops or to pay businesses.

So far, £1.2bn of paper banknotes have been deposited at the Post Office's 11,500 branches - £372m of £20 notes and £820m of £50.

More than £100m of the notes have already been deposited this month.

Martin Kearsley, Post Office banking director, said: "We're fully aware that people lead busy lives and some may put off depositing their paper £20 and £50 banknotes until the last moment.

"Postmasters and their staff are on hand to provide that human reassurance that your old notes have been deposited into your bank account and will provide a receipt too. Most Post Offices are open long hours including on Friday."

However, even after the deadline if you have a UK bank account you will still be able to deposit old paper banknotes at your bank branch or at a Post Office.

The new £20 note features artist JMW Turner, whilst the new £50 note features Bletchley Park codebreaker Alan Turing.