.
The polymer notes, which bear a portrait of Sir Winston Churchill, are 15 per cent smaller than the paper notes they are replacing and are said to last more than twice as long.
Because they are plastic, they are difficult to tear and can survive being put through the washing machine and other spills.
A smaller plastic £10 note featuring novelist Jane Austen will go into circulation next summer and a £20 polymer note, featuring the artist JMW Turner, is due by 2020.
The new notes went into circulation in September Credit: Steve Mould / Science Videos
Adapting bank cash machines, rail ticket machines, self-service tills and other vending machines across the country to cope with them has cost up to £236million, say consultants CMS Payment.
Other social media users have reported problems using the new plastic notes outside of London's public transportation network, including at pubs, in shops, bookmakers and in taxis.
Earlier this week we revealed that a number of people are attempting to raise big money by linking their new notes to the DEVIL .
One has been listed for a massive £300,000, with the seller explaining the 666 serial number is what makes it so valuable.
The online bidding frenzy comes after one person tried to flog their note with the AK47 serial number on it on eBay for £80,000 - only to find that the winning bidder wouldn't pay up.
And last week a Sun investigation revealed that while the new banknote was promoted as being twice as durable as previous bills, an experiment found that almost the entire note can be rubbed out with a normal pencil eraser .
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