How to Check If a Coin Is Genuine in the UK

Counterfeit gold and silver coins exist, and the most popular coins are copied the most. The good news is that most fakes can be caught with simple checks, and the expensive ones can be confirmed by experts without damaging the coin. This guide shows what you can check at home, what warning signs to look for and when to get an independent opinion.

Why authenticity matters

A coin that is not genuine is worth far less than you think, or nothing. Checking before you buy, and before you sell, protects you in both directions. It also shows buyers that you know what you have.

Checks you can do at home

1. Weigh it

Use scales accurate to 0.01g. A genuine full sovereign weighs 7.98g and a half sovereign 3.99g. Compare any coin with the published specification for that type and year. A coin that is off by more than a small amount deserves a closer look.

2. Measure it

Check the diameter and thickness with calipers. A sovereign is about 22mm across and a half sovereign about 19.3mm. A fake that matches the weight may not match the dimensions.

3. Look at the detail

Compare the design, the lettering and the edge with a known genuine example, using a magnifying glass or a clear photo. Warning signs include soft or blurred detail, uneven lettering, a rough or inconsistent edge, odd colour or a surface that looks too smooth or too bright.

4. Try a magnet

Gold and silver are not magnetic. A coin that sticks to a strong magnet is not gold or silver. But a coin passing the magnet test is not proof of authenticity, because many fakes use non-magnetic metals.

5. Check the price

A genuine gold coin cannot sell for less than its gold content. If a price is well below the gold value, something is wrong.

What not to do

• Do not scratch, file or drill a coin to see what is underneath.
• Do not use acid tests on collectable coins. They can mark the surface and destroy value.
• Do not clean it to see the detail better. See should you clean old coins.

When to get an expert opinion

Get an independent check when the coin is valuable, when the price looks too good to be true, when you are buying from a stranger or when something feels wrong. Dealers use professional equipment, including tools that analyse the metal without damaging the coin, and experience that matters a great deal.

Third-party grading

Services such as PCGS and NGC authenticate coins as part of grading and seal them in tamper-evident holders with a certificate number you can verify on their website. This is most useful for scarce or high-value coins. See graded gold coins.

A specialist dealer

A reputable dealer can check a coin quickly, often from photos first and then in person. We check every coin we buy, and we can give a free opinion on yours.

Buying safely

• Buy from a seller with a real address, a returns policy and clear terms.
• Keep your invoice and packaging.
• Be careful with online listings that use stock photos or sell at unusually low prices.
• Ask for clear photos of both sides and the edge.
• If a deal is urgent, slow down.

Selling safely

When you sell, expect the buyer to check your coins. That is a good sign. Be wary of a buyer who does not check, since they may be less careful about other things too. See where to sell old coins.

Frequently asked questions

Can I tell a fake just by looking?

Sometimes, but not reliably. Good fakes can look right, so weight, size and an expert opinion matter.

Are all old sovereigns genuine?

No. Fake sovereigns exist, so check the weight, size and details. See how much a gold sovereign is worth.

What should I do if I think I have a fake?

Do not sell it as genuine. Ask a dealer for an opinion.

Not sure about a coin?

Send clear photos of both sides and the edge through our free valuation form. We reply within 24 hours with no obligation. Or call free on 0800 978 8542.