There are 200,000 Â£1 coins worth up to Â£250 out there - and here's what to look out for if you get your hands on one.
The 'world's most advanced coin,' which was issued in March, was brought in to replace the old "round pound" which will be phased out in October.
But unlike the new Â£5 notes, coins do not feature serial numbers - so you'll have to dig a little deeper to catch the clues that make them worth more than a quid.
As with the current Â£2 coins, the 2017 Â£1 coin is bi-metallic - in this case an outer 'gold' coloured nickel-brass band with an inner 'silver' coloured cupro-nickel disc.
Because of this, any potential die errors during production, which occurs when the dies have become misaligned, could be worth a lot of money.
People should pay attention to both the floral crown on the reverse side for any rotations, as well as the Queen's head, which should sit directly above the new bevelled edge.