“And you can see on the Tudor rose coin the date is actually on the front, so there was no need for a date on the obverse head side of the coin.
So the Royal Mint accidentally minted the shield coin with this obverse by mistake and this is what led to the mule error being produced.
He then explained that you are looking for a shield design 20p coin with no date on the head side.
The Coin Collector continued: “As with any error the exact numbers produced are known but it's estimated between 50,000 and 250,000 of these coins managed to make their way into circulation.”.
“The main reason why this error was produced in the first place was because in 2008, the 20p definitive design changed from the Tudor rose to the shield.
