People have just a month left to spend or bank the 160 million paper fivers still in circulation before they lose their legal tender status.
From May 5, shops no longer have to accept the paper £5 note featuring prison reformer Elizabeth Fry as payment, and the new polymer banknote featuring Sir Winston Churchill will be the only Bank of England £5 note with legal tender status.
The Bank of England said more than 50% of "Fry fivers" have already been returned to be destroyed, leaving around 160 million in circulation.
Some banks and building societies may still accept paper £5 notes after May 5, but this is at their own discretion. The Bank of England will continue to exchange the old £5 notes for all time, as it would for any other Bank note which no longer has legal tender status.
The old paper fiver and the new £5 note have co-existed since the polymer banknote was first issued by the Bank in September 2016.
The new Bank of England fiver is stronger than its predecessor and boasts new security features making it harder to counterfeit. But it has been controversial as it emerged that traces of animal-derived additives were used in its production.
A public consultation has been launched by the Bank into how it produces new £20 polymer notes.
The Bank previously said it has held off signing supply contracts for the £20 polymer note, which is due to be released in 2020, in order to better understand "the range of public opinion" surrounding the use of tallow in banknote production and explore potential plant-based substitutes like palm and coconut oil.
In September this year, the Bank will issue a new £10 polymer note featuring author Jane Austen, recognising "her universal appeal and enduring contribution to English literature".