A UK gold hallmark is independent evidence of the precious-metal fineness of an item. For gold articles above the legal exemption weight, hallmarking provides an important consumer-protection check when an item is being sold or described as gold.
If you’re trying to identify a hallmark on a ring, chain, bracelet or other piece of jewellery, don’t look at the fineness number alone. A complete UK hallmark contains several separate marks that tell you more about the item.
Quick guide to UK gold hallmark numbers
The number inside a gold hallmark represents the minimum proportion of pure gold in the alloy, expressed in parts per thousand.
| Mark | Carat | Minimum gold content |
|---|---|---|
| 375 | 9ct | 37.5% |
| 585 | 14ct | 58.5% |
| 750 | 18ct | 75.0% |
| 916 | 22ct | 91.6% |
| 999 | 24ct | 99.9% |
So, for example, 375 means the alloy contains at least 375 parts gold per 1,000, or 37.5% gold. This corresponds to 9-carat gold. The remaining metal is made up of other metals in the alloy, which can affect colour, hardness and other characteristics.
What are the three compulsory parts of a UK hallmark?
- Sponsor’s or maker’s mark. This identifies the person or organisation responsible for submitting the item for hallmarking. It should not automatically be interpreted as the jewellery brand or original manufacturer.
- Millesimal fineness mark. This identifies the precious metal and its minimum fineness. On gold you may encounter numbers such as 375, 585, 750 or 916.
- Assay Office mark. This identifies the UK Assay Office that tested and hallmarked the article.
Additional optional marks, including a date letter, can also appear.
What does 375 mean on gold?
375 means 9-carat gold: 375 parts of pure gold per 1,000 parts of alloy, equivalent to 37.5% gold. This is particularly common on jewellery sold in the UK. However, finding 375 stamped onto an item isn’t the same thing as identifying a complete UK hallmark. Look for the other hallmark components as well.
If you’re comparing different gold purities, see our 9ct vs 14ct vs 18ct gold guide.
What does 585 mean on gold?
585 represents 14-carat gold, containing at least 58.5% pure gold. Although 14ct gold is widely used internationally, UK shoppers may encounter 9ct and 18ct particularly frequently.
What does 750 mean on gold?
750 represents 18-carat gold, containing at least 75% pure gold. A 750 fineness mark therefore indicates a substantially higher proportion of pure gold than 375/9ct gold. That doesn’t automatically make a piece of jewellery “better”: durability, construction, design, weight, workmanship and intended use matter as well.
What does 916 mean on gold?
916 represents 22-carat gold, with a minimum gold content of 91.6%. Because of its high gold content, 22ct gold has different physical characteristics from lower-carat alloys and is commonly associated with a richer yellow appearance.
UK Assay Office marks
The Assay Office mark tells you which UK Assay Office applied the hallmark.
| Assay Office | Mark |
|---|---|
| London | Leopard’s head |
| Birmingham | Anchor |
| Sheffield | Rose |
| Edinburgh | Castle |
London gold hallmarks
If you’re trying to identify a London gold assay mark, look for the leopard’s head. That is the current London Assay Office mark. It should be read alongside the sponsor’s mark and millesimal fineness mark rather than treated as proof of gold content on its own.
Older jewellery requires more care because hallmark designs and conventions have changed over time. Use an official hallmark reference before assigning an age solely from the appearance of a mark.
What is the sponsor’s or maker’s mark?
The sponsor’s mark identifies the registered person or organisation responsible for submitting an article for hallmarking. It’s sometimes casually called a maker’s mark, but you shouldn’t automatically assume it identifies the person who physically manufactured the jewellery. This distinction becomes particularly important when researching vintage and second-hand jewellery.
What do gold date letters mean?
A date letter can provide additional information about when an article was hallmarked. However, date letters are optional in the modern UK hallmarking system, so the absence of one doesn’t mean a hallmark is incomplete. Historical date-letter systems also need to be interpreted carefully: the surrounding shield, typeface, Assay Office and period can all matter.
How to read a UK gold hallmark step by step
- Find the fineness mark. 375 indicates 9ct gold fineness; 750 indicates 18ct.
- Identify the Assay Office mark. A leopard’s head points to London, an anchor to Birmingham, a rose to Sheffield and a castle to Edinburgh.
- Look for the sponsor’s mark. This identifies the registered sponsor responsible for submitting the article.
- Check for optional marks. A date letter or commemorative mark may provide additional information.
Reading the marks together gives you considerably more information than treating 375 or 750 as a standalone stamp.
Where are gold hallmarks found?
The location depends on the type and construction of the jewellery. You might find marks inside a ring, close to the clasp or end link of a chain or bracelet, on the reverse of a pendant, or on another discreet part of the article.
Hallmarks can be extremely small. Older pieces can also have worn or partially obscured marks. If you’re buying expensive jewellery online, ask the seller for a sharp close-up photograph of the actual hallmark rather than relying solely on the written product description.
What does a white-gold hallmark look like?
White gold uses the same gold fineness standards as yellow or rose gold. For example, 9ct white gold can carry a 375 fineness mark, while 18ct white gold can carry 750. The hallmark establishes fineness rather than simply describing the visible colour of the alloy.
The 1 gram gold hallmarking exemption
Gold articles weighing less than 1 gram are exempt from compulsory hallmarking in the UK. For articles consisting of precious and base metal, official guidance should be consulted regarding how exemption weight is calculated. Crucially, the exemption does not mean that every unhallmarked gold-coloured item weighing less than 1g is genuine gold.
Why a 375, 585 or 750 stamp isn’t necessarily a complete UK hallmark
A standalone number can provide useful information, but it isn’t equivalent to reading a complete British hallmark. When buying jewellery online, particularly higher-value pieces, ask for clear photographs showing all of the marks and make sure they are consistent with the seller’s description.
For additional checks, see our guide to how to tell if a gold chain is real.
375 vs 9CT, GP, GEP and GF
- 375 indicates 9ct gold fineness.
- 9CT/9K is another marking you may encounter referring to 9-carat gold.
- GP commonly refers to gold plated.
- GEP commonly refers to gold electroplated.
- GF commonly refers to gold filled.
These markings shouldn’t be interpreted in isolation when establishing whether an item carries a valid UK hallmark. A seller describing something merely as gold tone is also very different from describing it as solid gold. See our Gold Tone vs Gold Plated vs Solid Gold guide.
Gold-plated silver is different
Gold-plated silver is fundamentally different from solid gold jewellery. Where hallmarking requirements apply, the underlying precious metal is important. Read the complete material description rather than assuming that a gold-coloured surface means the article is solid gold.
Does a hallmark tell you how much gold jewellery is worth?
Not by itself. The hallmark can help establish the fineness, but intrinsic gold value also depends heavily on weight and the prevailing gold price. Two 9ct/375 chains can contain very different amounts of gold if one weighs substantially more than the other.
You can use the Touch of Midas Gold Value Calculator to estimate intrinsic gold value from weight and purity. Intrinsic metal value isn’t necessarily the same as retail, resale, antique or collector value.
Buying gold jewellery online: hallmark checklist
- Check exactly how the seller describes the metal.
- Look for the stated gold purity.
- Ask for clear photographs of the actual hallmark on higher-value items.
- Check gram weight as well as dimensions.
- Don’t treat a lone 375, 585 or 750 stamp as equivalent to a complete UK hallmark.
- Check returns and seller information before purchasing.
For the broader process, see our guide to buying gold jewellery online in the UK.
Frequently asked questions
Is 375 real gold?
375 represents a gold fineness of 37.5%, corresponding to 9ct gold. A standalone 375 stamp, however, should not automatically be treated as equivalent to a complete UK hallmark.
Is 750 gold better than 375?
750 contains a higher proportion of pure gold: 75% compared with 37.5% in 375 gold. Whether it is the more suitable choice depends on factors such as intended use, budget, construction and preference.
Does all UK gold have to be hallmarked?
UK hallmarking requirements include weight exemptions. Gold articles below the applicable exemption weight don’t require compulsory hallmarking solely because they’re being described as gold.
Can a fake item have 375 stamped on it?
A number stamped onto an item isn’t, by itself, the same as independent verification through a complete hallmark. Examine the complete set of marks and use appropriate professional testing when authenticity is uncertain or financially important.
Does white gold have a different hallmark?
White, yellow and rose gold use the same fineness system. For example, 9ct white gold can be marked 375 and 18ct white gold 750.
Editorial note: Hallmarking is regulated and requirements can change. For current legal requirements and historical hallmark identification, consult official UK hallmarking sources rather than relying solely on this guide.