More than £19billion worth of paper banknotes are still in circulation, ahead of a cut off date that will see them lose their legal tender status.
Paper £10 and £5 banknotes have already been withdrawn, but old style £20 and £50 notes will be redundant from September 30, under a shake-up to tackle fake money.
The Bank of England said it will continue to swap old notes for their face value, but households are being warned to use up the 775million paper notes before the autumn deadline.
