Rare 20p coins worth 50 pounds

The Royal Mint has issued a batch of 20p coins without the year on either side by accident.

A private company is offering £50 for the first 10,000 dateless coins registered by their owners.

Somewhere between 50,000 and 200,000 of these coins were minted with a new 'tails' design on one side and the older 'heads' image on the other.

Nick Hart of the London Mint Office dealership said: "We believe this extremely rare error will certainly get the public looking at the coins in their pockets again and noticing the excellent new designs launched by the Royal Mint last year on our coinage."

A Royal Mint spokeswoman told The Daily Telegraph: "The fact of the matter is they are still legal tender but if people want to pay more it's up to them."