Britons are being advised to take a close look at any new banknotes they receive, as some featuring King Charles III could be worth thousands of pounds to collectors. An expert has revealed that the key to a potential windfall lies in the serial number printed on the note.
What Makes a Banknote Valuable?
According to a collector known as the Coin Collecting Wizard, who shared his insights in a TikTok video on 20th December 2025, notes with very low serial numbers are the most sought-after. This applies to the new £5, £10, and £20 notes bearing the King's portrait, which began entering circulation to replace worn-out older notes. The design of the notes remains otherwise unchanged, and notes featuring Queen Elizabeth II will remain legal tender.
The serial number is located on the back of the note in the bottom right-hand corner. While lower numbers generally command higher prices, certain patterns are also highly desirable to numismatists.
Serial Numbers That Could Make You Rich
The expert provided clear guidance on what collectors are hunting for. Notes from the very first printed batches, often indicated by serial numbers beginning with 'AA' or the digit '1', attract the most interest.
Other valuable patterns include:
- Repeating sequences like '123456' or '11 11 11 11'.
- Palindromic numbers (those that read the same forwards and backwards), such as '2002'.
- Numbers with historical significance, like the King's birthday.
He cited examples like 'AA01', '22222222', and '1000003' as being particularly sought after. The potential values are significant: a low-numbered £5 note could fetch between £250 and £500, while £10 and £20 notes with prized serials could be worth £500 and £1,000 respectively. Exceptional examples could reach up to £5,000.
Official Confirmation from the Bank of England
The Bank of England's own website confirms the importance of serial numbers to collectors. The central bank stated that it deliberately holds back notes with especially low or symbolic serial numbers when a new design is released. These are typically donated to individuals and institutions involved in the note's development and are often later auctioned for charity.
This practice was demonstrated in 2020, when an auction of newly released £20 notes raised a combined £143,420 for good causes. This official stance underscores the legitimate collector market for these unique identifiers, which many people overlook in everyday transactions.
So, before you spend that new £20 note, take a moment to check its serial number. You might just be carrying a small fortune in your wallet.
