Believe it or not, there are millions of coins in circulation right now that are worth far more than their face value. We've rounded-up some of the most valuable examples to give you an idea about what to look for. Study them well and make sure you double- and triple-check your change in future.

Decorated with the iconic WWF panda and 50 other animals, this rare 50p was released as a special collectors edition in 2011. Special versions of the coin are up for grabs for around £1,000 on eBay, but even just any old version is worth a lot, with some coins selling for more than £10.

Only 485,500 of these special edition Commonwealth Games Northern Ireland £2 coins were minted – a relatively tiny run in coinage terms – and as a result, each one can fetch £25 or more these days.

The rarest sterling coin in circulation, the 2008 Kew Gardens 50p piece had a limited run of just 210,000. The shiniest, most pristine examples can command prices up to £120, so keep a keen eye out for these coins.

Thousands of undated 20 pence pieces fell through the net in 2008 following a mistake in the minting process. Be sure to check your change because these dateless coins go for up to £200 each on eBay.

All 2p featured the words 'New Pence' up to 1981 and 'Two Pence' thereafter. However, a batch in 1983 was accidentally minted with the 'New Pence' lettering. These coins are worth up to £700 each.

Several 1971 'silver' 2 pence pieces have been discovered lurking in small change and have fetched up to £1,350 at auction. A cupronickel rather than copper blank was left inside the minting machine in error, creating a small number of coins that quality control overlooked.

In 2012, the Royal Mint released a 50 pence piece to commemorate aquatic sports at the London Olympics. The original design (pictured on the left) showed the swimmer with water obscuring the face. This was tweaked to make the face more visible (pictured on the right) but not before 600 coins with the original design were released. These coins are now worth up to £3,000 each.