As the Royal Mint prepares to roll out its brand new design of pound coin, the old one in your pocket could be rising in value.

With the new 12-sided coin set to be introduced in March this year, shoppers will have until October 2017 to spend the old pound coin.

However, before parting with your pound, you may want to take a closer look, as it could be worth a little more than you first thought.

The pound coins to look out for

The rarest pound coin currently in circulation is the Edinburgh £1, according to ChangeChecker, with only 935,000 around.

This £1 coin is the rarest in circulation

It is the only £1 coin with a mintage below 1 million and if you have one, you could get around £35 for it online.

It currently has a reserve bid of £35 on eBay, or you can "buy it now" for £100.

The reserve price is £35

The coin is part of a capital cities series which also features Cardiff, the second rarest one pound coin.

The standard Cardiff coin is currently selling for around £25 on eBay.

Look out for these coins

Also worth more than just a few coins is the 2014 Thistle design, which comes in as the 5th most rare coin with just over 5 million in circulation.

On eBay, the Thistle £1 is currently listed at £11.99.

So check your pockets and purses, you could get more than you bargained for out of your old round pound.

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