The 20p piece is a “mule” coin dating from 2008 and was minted without a date on the coin due to an error.
The mistake means the 15-year-old coin is rare – and has become a real collector’s item, which sells for many times its face value.
What is a mule coin?
A batch of coins was accidentally issued without dates in 2008 due to an error in the minting process.
Before November of that year, the date on 20p coins would be found on the tail side. However, the Royal Mint switched it so that the date would now be next to the Queen’s head, but some were forgotten.
The old format was somehow used on the Queen’s side and the new format being used on tails side, and no-one spotted the mistake until it was too late.
As a result, the first batch of British coins with no date on them was released into circulation for the first time in more than 300 years.
Around 250,000 20p coins minted in November 2008 are believed to have entered circulation with no date.
And now this one, listed in Stonehouse, Gloucestershire, has sold on eBay, attracting a winning bid of £90, 450 times its face value.
Five incredibly rare and valuable British coins
What makes a coin valuable on eBay?
The 50 pence piece has become the most valued and collected coin in the UK, with many collectable designs appearing on its heptagonal canvas.
Its 27.5mm diameter makes it the largest of any British coin, and allows space for decorative pictures. It has often been used to celebrate big events over the past 50 years of British history.
Recommended reading:
The rarest coins tend to be of the greatest value, with the mintage (number of coins with each design made) being the fundamental attraction for collectors.
Along with the design, other aspects of the coin which increase value are the condition of the coin and whether it has an error in its design.
The way in which it is sold can also determine the coin’s value – while some coin collectors will bid vast amounts of money on eBay or at auction, others opt for more robust valuations by selling via a coin dealer.
