The notes were among the first to feature the new King, and were some of the earliest to be issued after the new £5, £10, £20, and £50 notes entered circulation in June.

A rare £20 King Charles III banknote has sold for £7,000 at a charity auction held by Spink and Son on behalf of the Bank of England on Thursday (July 11).

King Charles will now feature on the five, 10, 20 and 50 pound notes. (Supplied: Bank of England ) The Queen first appeared on BoE banknotes in 1960.

He said: "A King Charles £20 note worth £12,000 - have you got a new Charles note? Before you lose all thought and think you are rich, pay attention.

Notes with Queen Elizabeth II's portrait will remain legal tender even as the Bank of England releases notes featuring the face of the new king.

A handout photograph released by the Bank of England in London shows the design of the new 5-, 10-, 20- and 50-pound polymer banknotes featuring a portrait of King Charles III. Bank of England/AFP ...

The first-ever banknotes to feature King Charles III were released earlier this month and some of the very first notes are selling for thousands of pounds at auction ...

Rare 'Charles' £20 note selling for whopping £12,000 - but only if you have correct serial number Both £5 and £20 notes are selling for thousands of pounds - here's how to check if you have one ...

The new £5, £10, £20 and £50 notes will be printed only to replace worn-out currency or to meet any increase in demand, so bank notes with the images of the late queen and the current king ...