This comes as the new £50 note, which features scientist Alan Turing, enters circulation for the first time, joining the £5, £10, and £20 polymer notes.
Both the £20 and £50 notes have a variety of security features that can help operators confirm their authenticity.
For the £20 note, this includes a hologram image that alters if it is tilted from side to side (the words should change between ‘twenty’ and ‘pounds’).
Other security features including a portrait of the Queen printed on the window with ‘£20 Bank of England’ printed twice around the edge.
It also shows a round purple foil patch containing the letter ‘T’ on the back of the note, directly behind the silver crown on the front.
To find out more things to know about the polymer £20 note, see here.
For the new £50 note, there are a couple of main security features. One is a metallic hologram that changes between the words ‘fifty’ and ‘pounds’ when the note is tilted.
The other is a largely transparent window with a gold and green foil on the front, showing a details metallic microchip image.
All notes now polymer
Another security point to note on the £50 note is that, under a good quality ultraviolet light, the number 50 appears in bright red and green on the front of the note, against a duller background as well as a portrait of the Queen printed on the window with ‘£50 Bank of England’ printed around the edge.
All polymer notes have two key security features – a hologram that changes image and see-through windows.
The polymer £5 note was the first to change from paper, which was issued on 12 September 2016 and features Sir Winston Churchill. The £10 note followed this in September 2017 and features Jane Austen.
The latest edition of the £50 note means all Bank of England banknotes are now available on polymer.