How tiny error on your 20p coin could make it 300 times more valuable – is it worth digging through your loose change?

 A RARE error on your 20p coin means that it could sell for more than 300 times its worth

A rare Royal Mint 20p coin has sold on for more than £60 at auction.

The lucrative 20p piece is known as a “mule” coin, released into circulation in 2008 after a manufacturing error.

Traditionally, coins would be dated on the “tails” side. But in 2008, the Royal Mint decided to move the date to the “heads” side.

However, a minting error caused a small number of 20p coins to be released without any date on at all.

This was the first time in 300 years that British coins were released into circulation with no date on them.

As a result, the coins have become much more valuable than they are worth.

On an eBay auction, the rare 20p piece attracted 14 bids, eventually selling for £61.09.

There are said to be 250,000 20p coins minted in November 2008, all with no date on.

What other rare Royal Mint coins are in circulation?

This undated 20p piece isn’t the only rare – and valuable – coin in circulation.

The rarest is the Kew Gardens 50p, which was minted to mark the 250th anniversary of the gardens in West London.

There were only 210,000 of these collectors’ item minted and can sell for over £140.

Other rare British coins include special edition 50p coins minted for the 2012 Olympic Games.

Only 1.1 million of these limited edition coins were minted, with some selling at auction for over £10.

There have also been coins to celebrate British books, such as a Sherlock Holmes 50p coin and a Peter Rabbit coin.