Ebay sellers can often been found listing coins for thousands, claiming that they are rare.
Often these coins are not truly as valuable as sellers claim.
However, according to experts there are a number of 50p coins that really can make you hundreds.
The authors of book Spend It? Save It? What Should You Do? have created a guide to which coins are rare and worth more cash.
This includes two of the 2011 Olympic 50p coins.
Look out for these coin in your change:
Aquatics 50p (head with lines under water)
This coin is a true collectible, according to experts, and it worth in the region of £750.
The number of coins in circulation is not known, but a change in the design of the coin is credited for its rarity.
Initially, the coin had lines across the swimmer’s face representing water.
However, it was later decided that these lines obscured the face and that the design was better without.
The version of the coin with the head unobscured it worth only £4 in comparison.
Athletics 50p (Blue Peter edition)
A special edition of this coin, with a child’s drawing on it, was created dated 2009.
Only 19,751 of these coins exist and they can net you £100.
2009 Kew Gardens 50p
This coin is widely thought of as one of the rarest coins in circulation.
There are 210,000 of them in circulation, and they are worth £100.
Which are the rarest £1, £2, 50p, 20p, 10p and 2p coins?
Rarest £2 coins
The rarest £2 coin is the 2002 Commonwealth Games NI coin with 485,500 in circulation. This is followed by the 2002 Commonwealth Games Wales which has 588,500 in circulation.
Next up is the 2015 Navy, and there are 650,000 in circulation.
Rarest £1 coins
The most rare £1 coins are all part of a series celebrating the British capitals.
The rarest of these is the 2011 Edinburgh coin, with 935,000 in circulation. Of the 2011 Cardiff coins there are 1,615,000 in circulation, while the 2010 London coin has 2,635,000 in circulation.
Rarest 50p coin
The rarest 50p coin is the Kew Gardens coin, which is also the rarest coin in circulation. It there were only 210,000 minted.
The football Olympic 50p coin has 1,125,500 in circulation, and the wrestling coin has 1,129,500 in circulation.
It is not so easy to evaluate the rarest 20p coins, 10p coins and even 2p coins as exact circulation figures are not known.
However, various versions of the coins are known to sell for large sums.
These include the dateless 20ps, which are actually part of a run from 2008. There may be between 50,000 and 200,000 of these coins in circulation.
The 1983 ‘New Pence’ 2p coin can also sell for a huge sum, up to £650.