How to read gold hallmarks

Where to find the hallmark

Hallmarks are struck where they will not spoil the design and will not wear away quickly. On rings, look on the inside of the band, usually opposite the stone. On chains, check the clasp, the jump ring next to it or a small flat tag. On earrings, look on the post, the butterfly back or the hook. On pendants, check the bail and the back. On bracelets and bangles, check the clasp or the inside edge. On watches, look inside the case back.

The marks are small, typically half a millimetre to a millimetre tall. A 10× jeweller's loupe is ideal, but a phone camera with zoom in good side lighting also works well. If you photograph the mark you can also upload it to our AI hallmark checker, which reads the stamp and explains it.

The fineness mark

The most important part of any hallmark is the fineness, which states the purity of the gold. In Europe it is a three-digit number: 333, 375, 417, 585, 750, 875, 916 or 999. In the US and Asia you more often see karat marks: 10K, 14K, 18K, 22K or 24K, sometimes written KT or ct. Both are equivalent. Our karats and purity guide has the full conversion table.

Once you know the fineness, you know the price per gram: open the matching karat page, for example 14k (585) or 18k (750), to see today's figure.

UK hallmarks

British hallmarking is among the strictest in the world. Any gold item over 1 g sold as gold must carry a hallmark applied by one of the four Assay Offices. A full UK hallmark has three compulsory parts: the sponsor's mark (the initials of the maker or importer in a shield), the fineness mark (a number such as 375 in a shaped shield) and the Assay Office mark. The Assay Office symbols are a leopard's head for London, an anchor for Birmingham, a rose for Sheffield and a castle for Edinburgh.

Optional traditional marks include a crown for gold and a date letter. Before 1999 the date letter was compulsory, so on older British jewellery it lets you date the item to the year. Common British scrap is 9 carat, so see the 9 carat gold price in pounds for current values.

European and international marks

Many EU countries have state assay offices with their own symbols: France uses an eagle's head for 18 carat gold, Poland a woman's head with a number, the Czech Republic a stylised animal head, and so on. Countries that signed the Vienna Convention on hallmarking also use the Common Control Mark (CCM): a pair of scales with the fineness number between them. A CCM is recognised in all signatory countries without re-testing.

In Italy every item carries a maker's code: a star, a number and a two-letter province code such as AR for Arezzo or VI for Vicenza, alongside the fineness. In Germany marks are applied by the manufacturer under the law, so you usually see only the fineness and a maker's mark. In the Middle East and India, 21K, 22K and 916 marks are common, often with the BIS logo on Indian jewellery.

Marks that mean little or no gold

These stamps indicate plating or cladding rather than solid gold:

• GP or GEP — gold plated or gold electroplated: a microscopic gold layer over base metal.
• HGE or HGP — heavy gold electroplate: a slightly thicker layer, still negligible value.
• RGP — rolled gold plate: a thin sheet of gold bonded to base metal.
• GF or 1/20 12K — gold-filled: a thicker bonded layer; 1/20 means 5% of the weight is 12 carat gold.
• Vermeil — gold plating over sterling silver; valued mainly as silver.
• 925 on a yellow item — sterling silver, possibly gold plated.

Fake and misleading hallmarks

Stamps can be faked, especially on items sold online or abroad. Warning signs include marks that look shallow or blurred while the rest of the item is crisp, numbers that do not match any legal standard, a 14K stamp next to signs of plating wear at the edges, and an item that feels too light for its size. Magnets are a useful quick check: gold is not magnetic, so if a piece snaps to a strong magnet, it contains iron or nickel. A magnet test does not prove an item is gold, though, because many base metals are not magnetic either.

Any serious buyer will test the metal, either with acid on a touchstone or with an XRF analyser. If you are buying gold, insist on hallmarked items from reputable sellers. If you are selling, ask the buyer to show you the test result.

Hallmarks on coins and bars

Coins do not carry a hallmark in the jewellery sense; their weight and fineness are guaranteed by the issuing mint and are often written on the coin itself, for example '1 oz fine gold 999.9' on a Maple Leaf. Bars from accredited refiners show the refiner's logo, the weight, the fineness and a serial number. Our gold coin melt values list the gold content of every common coin.