NEED a cash boost this spring? You could be sitting on a fortune if you've got a rare £1 coin hiding in your wallet.
With some of the most unusual coins fetching more than 10 times their face value on eBay, you could earn yourself a pretty penny.
Here are the coins you need to keep an eye out for if you want to be quids in...
What are the rarest £1 coins?
Here are the ten rarest £1 coins still in circulation as well as what they are currently selling for on eBay.
2011 Edinburgh £1
According to the blog , the rarest one pound coin currently in circulation is the Edinburgh £1.
The coin was part of a series depicting the four capital cities of the UK and is the only £1 coin with a mintage below one million.
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ChangeChecker's calculations suggest there are probably 935,000 Edinburgh City coins still in circulation.
On eBay, the highest price we've seen one of these coins go for recently
That means you could sell it for more than 10 times its face value.
2011 Wales Cardiff City £1
This coin was also part of the capital cities series, but it is slightly less rare, with an estimated circulation of 1,615,000.
Designed by Stuart Devlin, goldsmith and jeweller to the Queen, this coin depicts the circular Coat of Arms of Cardiff as the principal focus to represent Wales.
The highest price we could find on eBay recently for the coin
2010 London City £1
A third coin released as part of the capital cities of the UK series was the London £1.
The coin shows the portrait of the Queen and on the reverse side shows the four official badges of the capital cities of the UK, with a magnified image of the badge of London.
ChangeChecker estimates there are 2,635,000 coins left in circulation.
But you're unlikely to make a mint out of yours if you find one.
The highest amount we saw this £1 sell for was previously
2008 Royal Arms £1
There were 3,910,000 million of these £1 coins minted in 2008.
It features the Royal Shield of Arms coin, and shows various designs including lions and a heart on the shield.
It won't go for that much if you find one though.
We found one being flogged on eBay
2014 Thistle and Bluebell £1
In 2014, the Royal Mint launched two new £1 coins – one for Northern Ireland and one for Scotland.
This Scottish coin design features the thistle and bluebell, and is the fourth rarest coin in the UK.
There are an estimated 5,185,000 still in circulation.
You won't get too much for them though - we saw one previously being sold for .
2013 Daffodil and Leek £1
This daffodil pound coin was released in 2013 as a floral set alongside a rose pound coin.
The daffodil is the national flower of Wales, while the leek is also a national emblem of Wales.
The pair of coins marked the first release of a commemorative £1 since 2011.
On eBay, these coins are going for around
2013 Rose and Oak £1
The rose and oak coin was part of a floral set along that launched in 2013.
It's still fairly unusual with around 5,270,000 still in circulation.
Unfortunately, they're not selling for much at the moment, the highest recent price we could see was on eBay.
2014 Flax and Shamrock £1
The 2014 flax coin was released alongside the thistle coin, to complete the series of four coins that began in 2013.
It continues the tradition of honouring the home nations of Britain by featuring familiar floral emblems.
However in this series, the emblems are paired together with other less well-known floral symbols.
This design features the shamrock and flax for Northern Ireland.
It will fetch up to
2010 Belfast £1
There are more than 6.2million 2010 Belfast coins in circulation, meaning it is the ninth rarest £1 coin in the UK.
The design is part of the "City Series" collection, and you can get up to for circulated coins on eBay.
1988 Crowned Shield £1
This coin depicts one of the UK's heraldic emblems – the royal arms of the queen, topped by the crown of St Edward.
There are 7.11million in circulation making it the fifth rarest pound coin there is.
We saw one being sold for last month.
How can you check the value of a coin?
If you think you’ve got a coin that could fetch a few bob then it’s worth getting it verified.
The Royal Mint can tell if your coin is legit and not counterfeit, but doesn’t do valuations.
In the meantime, if you want a coin valued you could contact Sovereign rarities - a team of coin specialists, collectively with over one hundred years of experience.
Stanley Gibbons, which specialises in stamp collections, also offers a free valuation service through its rare coin division, called Baldwin’s.
For more common coins you could try selling them online, via a website like eBay.
Here are the most valuable 50p coins in circulation that could bring home £3,000 if flogged together.
Beatrix Potter 50ps, Suffragettes and Battle of Hastings designs are also considered rare and could fetch you a bit of cash.
Think you’ve got a rare coin? Here’s our guide to find out if it’s worth a mint and cash in.