Authenticate your 1 oz Gold Britannia (2013-2025)

How to spot a fake Gold Britannia

The 1 oz Gold Britannia is The Royal Mint's flagship bullion coin. This guide covers the .9999 fine coins struck from 2013 to 2025. It is widely traded in the UK and abroad, which makes it a natural target for counterfeiters. No single check proves a coin genuine, but a handful of simple tests, done in order, will catch most fakes and tell you when a coin needs a closer look.

What fakes exist

• Gold-plated base metal. Brass, copper or steel with a thin gold layer. Usually the wrong weight or size, and the most common type.
• Tungsten-core fakes. Tungsten is almost as dense as gold, so a tungsten core wrapped in or plated with gold can come close to the right weight. These are the hardest to catch with a scale alone.
• Low-purity gold. Struck or cast in a lower-carat alloy. Often looks a little more orange or pale than pure gold.
• Cast copies. Made from a mould taken from a real coin. Details are soft and the surface may be grainy or pitted.

The checks, in order

1. Weight

A genuine coin contains one troy ounce of fine gold (31.10 g), and because it is .9999 fine, that is also its total weight. Use a scale that reads to 0.01 g and check it with a calibration weight first.

• A coin that is clearly light or heavy is a strong warning sign. Plated base-metal fakes are usually light.
• A correct weight doesn't prove the coin is genuine: a well-made tungsten fake can come close. Weight rules coins out; it doesn't rule them in.

2. Diameter and thickness

Measure with digital calipers and compare against the facts box on this page. To hit the right weight, a fake made of a lighter metal has to be thicker or wider than the real coin. A coin with the right weight but the wrong thickness is a fake. Measure the diameter in more than one direction; it should be perfectly round.

3. Design and strike quality

Look at the coin under good light with a 10x loupe, ideally next to a coin you know is genuine or high-resolution photos from The Royal Mint or a major dealer.

• Reverse: Britannia's trident, shield, helmet and drapery should be crisp, with clean edges and fine detail in the waves behind her.
• Obverse: the monarch's portrait should be sharp, with even, well-spaced lettering. Check that the portrait matches the date: Queen Elizabeth II through 2022, King Charles III from late 2022/2023.
• Warning signs: soft or "melted" detail, letters that are thick or uneven, a grainy or pitted surface, small bubbles, or a colour that looks too orange, too pale or too brassy for pure gold.

4. Security features (2021 onwards)

From 2021 The Royal Mint added anti-counterfeiting features to the Britannia reverse. Check them by tilting the coin under a single light source and with a loupe:

• Latent image: a small symbol near the shield switches between a trident and a padlock as you tilt the coin.
• Surface animation: fine lines in the background behind Britannia give the appearance of moving waves when tilted.
• Tincture lines: heraldic hatching on the Union Flag detail of the shield.
• Micro-text: tiny lettering ("DECUS ET TUTAMEN") around the design, readable under magnification.

On a coin dated 2021 or later, a missing, blurred or static feature is a serious red flag. Coins dated 2013–2020 don't have these features, so rely on the other checks.

5. Edge

A genuine coin has an even, milled (reeded) edge. Look at the whole edge under magnification. Uneven reeding, flat spots, or a line running around the edge, which can mean a cast coin or a two-part coin with a different core, are reasons to reject it.

6. Magnet

Gold is not magnetic. Hold a strong neodymium magnet against the coin. If the coin sticks or is pulled at all, it is a fake. Passing tells you less: tungsten, brass and copper are non-magnetic too, so this check only rules out fakes with iron or steel in them.

7. Ping test

A coin's ring depends on its metal, size and shape. A genuine Gold Britannia rings at a characteristic set of pitches, and a coin made of a different metal, or with a different metal inside, will usually ring differently. Use the ping test at the top of this page: balance the coin on a fingertip, tap it gently with another coin, and compare.

The ping test is one strong check among several, not a final verdict. Background noise, how you hold the coin, a capsule, or damage like a bend or rim knock can all affect the result, and some fakes may ring close enough to pass. If the result is unclear, take it out of the capsule, try again somewhere quiet, and combine it with the other checks.

8. Specific gravity, XRF and conductivity

If the coin passes the home checks but you still have doubts, or it is a large purchase:

• Specific gravity (weighing in air and in water) catches most base-metal and low-carat fakes. Gold and tungsten are too close in density for it to reliably catch a tungsten fake.
• XRF (offered by many dealers and assay offices) reads the surface composition and catches low-purity gold and plating over base metal, but it may not see a core under a thick gold layer.
• Conductivity testers such as the Sigma Metalytics read below the surface and can help with plated and core fakes.

Tips for specific dates

• 2013–2020: no 2021-style security features, so lean on weight, dimensions, ping and a professional test for anything you're unsure of.
• 2021–2025: check all four security features as well. A coin dated 2021 or later without them shouldn't be trusted.
• Special finishes and editions (proof, privy marks, special reverse designs): check the exact design for the year against The Royal Mint's records. A design on the wrong date is a fake.

If you suspect a fake

1. Stop. Don't add it to your holdings or pay any more for it, and keep the packaging and payment records.
2. Test further. Repeat the checks carefully, and compare against a coin you know is genuine if you can.
3. Get a second opinion. Take it to an established bullion dealer or an assay office for XRF or other testing.
4. Contact the seller and use your buyer protection or payment dispute process if you bought it recently.
5. Don't sell it on or pass it to someone else as genuine. If you confirm it is a fake, you can report it to the platform you bought it on and to Action Fraud (in the UK).

The best protection is buying from The Royal Mint or an established dealer, and being wary of any offer that is well below the usual market price.

For other Royal Mint bullion, see the Silver Britannia guide and the Gold Sovereign guide.