Rare two-pence piece is set to fetch up to £400 at auction today

A rare two-pence piece is set to fetch up to £400 at auction today – and Brits have been urged to check their change in case they've got one too.

A rare two-pence piece is set to fetch up to £400 at auction today – and Brits have been urged to check their change in case they've got one too.

The coin, dated 1985, was found in a piggy bank in the late 1990s, and could now sell for up to 20,000 times its face value at auction.

Unlike other 2p coins, it's made from cupronickel, a metal alloy normally used for higher-denomination coins like 10 pence pieces.

As a result, it's got a unique silver colour, instead of the usual bronze tint, and will stand out in a handful of change.

The coin goes under the hammer at RWB Auctions in Royal Wootton Bassett at 11am today.

Coin expert and YouTuber Christopher Collects, who works with The Britannia Coin Company, sister firm to RWB Auctions, described how the coin may have come out in silver.

He said: 'It's been struck on the wrong metal disk.

'So somehow a cupronickel silvery-looking blank has managed to get into one of the striking machines and has filtered into the machine whilst they were striking two pence coins.

The rare silver 2p piece which is expected to fetch up to £400 at auction today

It is believed to have been created when the coin was struck with the wrong metal disk

'There's this great big metal bin that's full of all these blanks – because they're not a coin until they've been struck – and they just lift them up and tip them into a hopper.

'It all gets fed into the machine, and so one of these blanks has managed to get stuck in the machinery and has then dislodged while they're striking two pence coins.'

He continued: 'They can strike up to 16 coins a second in one of those machines, so you can imagine the sheer volume of coins that they produce when they're minting them for circulation.

'They can't check every single one, so normally they would grab a handful and check them over, and it's obviously not been in the handful of coins that they've pulled out to check.'

The coin features a crowned portrait of Queen Elizabeth II by artist Raphael Maklouf which was used on British currency between 1985 and 1997.

The reverse features the badge of the Prince of Wales – ostrich plumes within a coronet.

Its cupronickel composition has been confirmed using x-ray fluorescence (XRF) technology, and it's also been authenticated by a third party, the Numismatic Guaranty Company.

Auctioneers estimate it will fetch between £300 and £400 at auction.

Pictured: An ordinary 2p piece. It is not known how many of the rare coins are in circulation

It's unclear how many cupronickel 2p pieces are in circulation.

'It's anybody's guess,' said Christopher, 'there is no way to track back how many have been made.'

The coin expert says there could be one in your pocket right now.

He said: 'If you don't look, you definitely won't find, is what I would normally say.

'It does stand out if you've got a handful of two pence coins and you have a silver-looking one rather than a coppery-looking one.

'This one was found in a piggy bank, so there's every chance that there could be more out there, but they're not going to be in huge numbers.'

He added: 'This just sort of highlights the kind of treasure that you can find in your change, in your pocket, in your money jars.'