Going to the UK? Check your change

If you’re planning a holiday in the United Kingdom this year, check your coins. The Royal Mint at Llantrisant in Wales churned out tens of thousands of 20 pence coins with no date on them, the BBC reported. The mix up happened because on the new design for the 20p coin the date was switched from the tails to the heads, but when the coins were made, the mint used the new tails die and the old heads one.

So what? Well, here’s the kicker–coin collectors say they could be worth £50 ($83) each. This is because such slips are rare and no British coin has been issued without a date for more than three hundred years.

The mint estimates that between 50,000 and 200,000 coins were put into circulation, which means that not only are they lousy at quality control, but they don’t keep track of distribution either.