How to find out if your £1 is worth £30 as round coinage is phased out

The Royal Mint prepares to roll out more than a billion 12-sided £1 coins

The rarest £1 coin currently in circulation is the Edinburgh £1 (ChangeChecker)

More than a billion brand new £1 coins are being struck in time for its launch in March, the Royal Mint said in its New Year’s Day announcement. The new 12-sided coin, described as “the most secure coin in the world", will replace the traditional circular £1.

However, before spending or exchanging your round pounds it’s worth noting that some are worth much more than their face value.

The rarest £1 coin currently in circulation is the 2011 Edinburgh £1 which was part of the series depicting the capital cities of the UK, according to ChangeChecker.

The website allows users to quickly identify coins and their scarcity as well as find information on those which have become popular with collectors.

The Edinburgh design is the only £1 coin with a mintage below 1 million and is currently selling for up to £30 on eBay.

The 2011 Cardiff coin and 2010 London £1 coins - issued as part of the same series as the Edinburgh design - can also command up to £30, according to the latest eBay listings.

While, the 2008 Royal Arms £1 with 3,910,000 in circulation, is the fourth rarest £1 coin in the UK.

This was followed by the the 2014 Thistle £1, which features the thistle and bluebell for Scotland. The coin is currently was selling for nearly £12 on eBay.

(eBay (eBay)

Last year, a 2p coin sold for almost £1,400 at auction because it was silver instead of copper.

Meanwhile, the Bank of England’s first ever plastic note were selling for up to £800 on eBay or more than 160 times their face value.

The new-look 12-sided £1 coin features the national flora of the UK’s four countries emerging from a coronet.

Dr Kevin Clancy, director of the Royal Mint Museum, said: “This year we also mark the achievements of Jane Austen, Sir Isaac Newton and The Royal Flying Corps – all pioneers in their own field.

“The British public should start to see these coins appearing in their change from spring 2017.”

A new £2 coin has been created that displays a First World War biplane and is marked, “The War In The Air”.