Everything you need to know about Polymer Banknote Serial Numbers

The new King Charles III banknotes entered circulation on 5th June 2024, and whilst the reverse designs remain unchanged, this is the first time we’ve ever seen a King feature on UK banknotes – as they were introduced well into Queen Elizabeth II’s reign.

King Charles III £10 banknotes
The new King Charles III banknotes will enter circulation on 5th June 2024
Image credit: Bank of England

It’s not that long ago, however since we last saw a major change in our banknotes, with the introduction of the first polymer banknotes in 2016. The polymer notes were issued to replace paper banknotes with a cleaner, safer and stronger alternative, and by 2022, all banknote denominations had been replaced with a new polymer version and the older paper notes were withdrawn from circulation.

£5, £10, £20 and £50 Polymer Banknotes
£5, £10, £20 and £50 Polymer Banknotes
Image Credit: Bank of England

The new polymer notes caused quite a stir, with collectors rushing to secure the notes with the lowest serial number. But what happened to the very first notes of each denomination?

£5 Polymer Banknotes

Whilst collectors were on the hunt for polymer £5 banknotes with low serial numbers when they first entered circulation in 2016, the very first ones never actually made it into circulation.

The Bank of England always hold back some of the notes with the earliest serial numbers, donating them to people or institutions that were involved in the development of the note, or who traditionally receive a note when a new series is issued.

Serial number Recipient 
AA01 000001 – Her Majesty The Queen 
AA01 000002 – Prince Phillip 
AA01 000003 – Prime Minister 
AA01 000004 – Chancellor of the Exchequer 
AA01 000005 – The Governor (for the Bank) 
AA01 000006 – Deputy Governor (responsible for Notes) 
AA01 000007 – The Chief Cashier 
AA01 000008 – Bank of England Museum 
AA01 000009 – British Museum 
AA01 000010 – Churchill family 
AA01 000011 – Permanent Secretary of the Treasury 
AA01 000012 – Chair of the Bank’s Court 
AA01 000013 – Chris Salmon (former Chief Cashier) 
AA01 000014 – De La Rue 
AA01 000015 – Innovia 
AA01 000016 – Royal Mint 
AA01 001704 – Blenheim Palace 
AA01 001874 – Lord King (former Governor) 
AA01 001910 – The Home Secretary 
AA01 001924 – The Chair of the Treasury Select Committee 
AA01 001929 – George Osborne (former Chancellor of the Exchequer) 
AA01 001940 – The Governor 
AA01 001941 – The US Ambassador to the UK 
AA01 001942 – The Foreign Secretary 
AA01 001945 – Churchill War Rooms 
AA01 001951 – David Cameron (former Prime Minister) 
AA01 001960 – Churchill Archive, Churchill College Cambridge 
AA01 001965 – Chartwell 
AA01 002016 – Andrew Bailey (former Chief Cashier) 

Polymer £5 banknote
Image Credit: Bank of England

The Bank of England also conducted an auction of low serial numbered £5 notes on 3 October 2016, which raised £194,500 to be split between three charities – The Myotubular Trust, The Lily Foundation and Bliss. 

The lowest polymer £5 note with the serial number AA01 000017 sold for £4,150!

It’s also worth looking out for banknotes with serial numbers that could be considered collectable, such as AK47 due to the machine gun connotations, and 007 which could be desirable to James Bond fans.

£10 Polymer Banknotes

The UK’s first polymer £10 note, featuring Jane Austen on the reverse, entered circulation on 14th September 2017, and, similarly to the £5 note, the first ones printed were donated.

In October 2017 some of the first Jane Austen Polymer £10 notes were auctioned and raised a staggering £260,900 for charities Candelighters, Haven House Children’s Hospice and Macmillan Cancer support.

The £10 note with the lowest serial number AA01 000010 sold for an incredible £7,200.

The polymer £10 note with the serial number AA01 000010 sold for a staggering £7,200

Other notes that fetched hefty sums were AA01 000011 and AA01 000014, selling for £5,200 and £3,500 respectively.

£20 Polymer Banknotes

Issued in 2020, the £20 was the third polymer banknote denomination to enter circulation.

Did you know? The letters at the beginning of a banknote’s serial number indicate its position on the sheet on which it’s printed. The 6 numbers that follow the letters refer to the number on the sheet the note is printed on.

With the £20 note being larger than the £5 and £10 notes, less notes were printed per sheet, however there were still an incredible 59,940,000 notes with an serial number starting AA!

Polymer £20 Banknote sheet
Polymer £20 Banknote sheet
Image Credit: Bank of England

As the polymer £20 note featured JMW Turner on the reverse, some serial numbers matching key dates relating to the painter the became highly collectible.

For example, 23 041775 represents Turner’s date of birth, whilst 19 121851 relates to his death and 17 751851 would be his birth and death combined.

True Turner fans might also look for 18 381839 representing the date he painted ‘The Fighting Temeraire’ (which featured on the new £20 note) and the date the painting was exhibited at the Royal Academy respectively.

£50 Polymer Banknotes

On the day that would have been Alan Turing’s 109th birthday (23rd June 2021), The Bank of England issued their final banknote in the polymer series, celebrating the famous scientist and mathematician.

The Polymer £50 note features famous scientist and mathematician, Alan Turing
Image Credit: Bank of England

As is tradition, Queen Elizabeth II received the very first polymer £50 note printed with the serial number AA01 000001, however AA01 000010 was donated to the Turing family in honour of Alan Turing featuring on the reverse of the £50 note.

Again, certain serial numbers matching key dates relating to Alan Turing became collectable, such as 23 061912 which represents Turing’s date of birth, 07 061954 which relates to his death and 09 071941 which represents the date that the enigma code was cracked by Turing and his team at Bletchley Park during WW2.

Safely store your banknote collection

With the release of these new banknotes, now’s the perfect time to start your banknote collection, by owning the Change Checker Polymer Banknote Collecting Pack – with space to securely house all four of England’s polymer banknotes!

Secure yours for just £9.99 (+p&p) >>

How to spot a counterfeit banknote!

In 1725, printed banknotes were first introduced in the UK, with the purpose of fixed denominations. The £20 banknote came first and following a shortage of metallic currency during the Seven Years’ War in 1759, £10 and £15 notes were issued. 

The £5 note was the last to be introduced in 1793. But since their introduction, banknotes have been subject to fraudulent behaviour, so much so, additional banknotes have been executed partly to make forgery of such more difficult. 

Fraudulent notes are also called ‘counterfeit banknotes’ and although less and less are going into circulation — with less than 1 in 40,000 banknotes being counterfeit in 2021 — it’s still an important topic to discuss!

Although polymer banknotes are a lot harder to replicate than the traditional paper ones, you should still check your notes when you receive them. But the questions is, how do you spot a counterfeit banknote? 


For every polymer banknote, a good starting point is to look at its size.

The higher the value, the larger it is. Here we can see the approximate sizes of the £5, £10 and £20 polymer banknotes:

The sizes of the £5, £10, and £20 polymer banknotes in comparison to one another.
The sizes of the £5, £10, and £20 polymer banknotes in comparison to one another.

Security Features

Crucially, you should always check your polymer banknotes for the following key security features:

Changing hologram:

  • All polymer notes when tilted from side to side and up and down, should feature word changes within their holograms.
  • For the £5 banknote, the words should change between ‘Five’ and ‘Pounds’, the £10 banknote between ‘Ten’ and ‘Pounds’ and so on. 

See-through windows:

  • Each banknote of denomination has a metallic image over the see-through window on it.
  • Both the £5 and £10 polymer notes have gold foil on the front of the note within this part and silver on the back.
  • The £20 note has a blue and gold foil on the front of the note for the metallic image and silver on the back.
  • Lastly, the £50 note has gold and green foil on the front and silver on the back.

Feel of polymer and raised print:

  • Polymer is a thin and flexible material so check that the material of your banknote feels this way.
  • On each denomination banknote as well, the words ‘Bank of England’ should feel raised.

Foil patches:

  • Each banknote denomination will have a different foil patch on it.
  • For the £5 note, this is a green foil patch — it is circular and spells ‘BLENHEIM’ to commemorate where Churchill was born.
  • The £10 note has a copper foil patch, and this is shaped as a book.
  • Check it contains the letters ‘JA’, in tribute to Jane Austen.
  • A purple foil patch shaped in a circle with a ‘T’ at its centre, to represent JMW Turner, is imprinted on the £20 note and lastly, a metallic red foil patch can be found on the £50 note and contains the letters ‘AT’ for Alan Turing.
  • The patches can all be located behind the silver crown on the front of the notes.

The queen’s portrait in the see-through window:

  • The Queen’s portrait which is printed within the see-through window can be found on all the banknotes with the respective denomination and the words ‘Bank of England’ printed twice.
  • For example, on the £5 note the inscription ‘£5 Bank of England’ will be printed twice around the windows edge.

This is a just a small selection of the security features that you can find on your polymer banknote. Can you name some of the other features? Let us know in the comments below!

Counterfeit banknotes have no monetary value and cannot be reimbursed. The best thing to do if you encounter a counterfeit banknote is take it to your nearest police station.

They will ask you to fill out a form and once taken from you, will send the suspect note(s) to the National Crime Agency and if found to be counterfeit, to the Bank of England for further examination. 

If you’re interested in coin collecting, our Change Checker web app is completely free to use and allows users to:

– Find and identify the coins in their pocket
– Collect and track the coins they have
– Swap their spare coins with other Change Checkers

Change Checker Web App Banner 2 Amends 1024x233 1 1024x233 - Your January 2019 Scarcity Index update!

Sign up today at: www.changechecker.org/app

£19bn in old UK banknotes and coins not cashed in!

£18.9bn worth of paper banknotes and round pounds remain in circulation, with over 113 million of these being £5 notes! Despite it being nearly five years since the paper £5 note lost its legal tender status*, it seems people are holding on them.

In fact, you might just have one in your pocket/wallet/down the back of the sofa right now!

Whilst the paper £10 and £5 notes have been withdrawn from circulation, the £20 and £50 paper banknotes will hold their legal tender status until 30 September 2022.

According to the Bank of England, 775 million paper banknotes remain in circulation:

  • Paper £5 notes in circulation: 113 million
  • Paper £10 notes in circulation: 73 million
  • Paper £20 notes in circulation: 360 million
  • Paper £50 notes in circulation: 209 million

That’s a lot of banknotes!

*Whilst the paper £5 and £20 notes are no longer legal tender, they will always be exchanged by the Bank of England for their face value.

There are also supposedly £105m of old round pound coins in circulation, according to the Royal Mint.

After more than 30 years in the nation’s pockets, the familiar round £1 coin was replaced with an all new, 12-sided £1 coin in 2017, in a bid to crack down on counterfeiting.

It lost its legal tender status at midnight on 15 October 2017 and the Royal Mint asked the public to return their round pounds as they phased in the new 12-sided coin.

However, out of 1.6 billion round pounds to be returned, about 1.45 million were counterfeits!

The UK’s 12-sided £1 coin is described by the Royal Mint as the ‘most secure in the world’, with a string of anti-counterfeiting details. Find out more about the security details of this coin here!

Round pounds can still be deposited at high street banks – but can no longer be spent in shops.

Have you held on to your round pounds or paper notes? Let us know in the comments below!

Never miss a UK coin issue!

Join the Change Checker UK CERTIFIED BU Subscription Service and receive new UK coins sent to your door without the hassle of placing orders on the day of release!

Don’t miss your chance to get ahead of the crowd and be one of the very first collectors to receive the latest UK new issue coins as soon as possible after their release.