A COIN expert has revealed the exact details to uncover a faulty 20p piece worth almost £90.
Mining errors occur when coins are hacked, making them highly sought after by collectors.
That means the pieces of your daily change can grow to many times their face value.
Two pence coins have each sold for up to £1,000, while faulty 50p coins cost £100.
A 20p piece can also be worth almost £90.
TikTok user @coincollectoruk shared in a recent video how 250,000 “mule” coins were launched in 2008, but there is no date on them.
They explained: “On the back of the shield there is a date on the bottom.
“However, in 2008, the Royal Mint issued coins with no date by mistake.
“This is called the mule bug, estimated at 250,000.”
The Royal Mint’s website says the undated 20p coin is still legal tender, so you can use it in shops.
And that means it’s likely to show up in your spare change, so keep an eye out.
How to spot a rare coin
A coin is generally considered rare if it has a low mint – this is regulated by The Royal Mint.
The minting number is related to the number of coins generated, so the lower the number, the rarer the coin.
You can find out which coins are rare and what they look like on The Royal Mint’s website.
But some are also considered rare due to manufacturing defects.
They have been known to sell for hundreds of times their face value because there are so few.
If you want to find out if your coin is mishandled, you can check out our list of rare coins here.
Meanwhile, you can use sites like changechecker.org that regularly post about buggy coins.
How to sell a rare coin
You can sell a rare coin in a number of ways, including through Facebook, eBay, or auctions.
But be wary of the risks. Some people have been targeted by Facebook scammers.
Scammers say they are planning to buy the item and ask for money in advance to have it delivered to your home.
But you end up sending them free money and they never intend to take your item.
Face-to-face is always best when buying or selling on Facebook Marketplace and in public.
And most sellers prefer a face-to-face cash transaction to make sure it’s legit.
The safest way to sell a rare coin is most likely by auction. You can organize this with The Royal Mint’s Collector Service.
It has a team of experts that can help you validate and value your coins.
You can be reached by email and a member of the pricing team will get back to you.
However, you will be charged for the service – costs vary depending on the size of your collection.
Finally, you can sell rare coins on eBay – but it charges you 10% of what you make, including postage and packaging.
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