If you have this rare pound coin it could be worth thousands

Check ALL your pound coins before spending them

Drop everything and check all of the new £1 coins in your purse because, if they feature the below mistake, they could be worth as much as three grand.

You heard us right. Three thousand Great British pounds.

One lucky window cleaner from Hull noticed an error on one of the new pound coins and decided to check out how much money the unique find was really worth. As it turns out, it's worth quite a lot.

The faulty £1 coin – which, according to The Mirror, the Royal Mint has confirmed to be authentic – is engraved with both the years 2016 and 2o17 by mistake.

Of course, it's not the first time that Brits have cashed in on coin mistakes (or indeed rare five pound notes). For example, if you're lucky enough to have one of these rare 50p coins in your pocket or down the back of the sofa, it could also earn you thousands of pounds for a rainy day.

Fancy your chances? Here's how to spot how much your pound coins are really worth.

Window cleaner and coin collecting enthusiast Richard Bird, who has since had the coin valued and says it's worth £3,000, plans to sell the lucky find on rather than keeping it in his collection. We don't blame him, really.

It just goes to show that attention to detail pays off – in this case, literally.

We wish we could be so fortunate. Here's hoping one of the rare coins lands in our lap sometime soon.