How do you read a UK hallmark on gold, silver or platinum?
Short answer
A UK hallmark carries three compulsory marks: the sponsor's mark, the millesimal fineness figure and the assay office mark. Under the Hallmarking Act 1973 it is legally required to sell an item described as gold above 1g, silver above 7.78g, platinum above 0.5g or palladium above 1g. Below those weights, and on many antiques, an unmarked piece can be entirely genuine.
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Why a hallmark is worth more than a stamp
A '750' scratched into a ring is a claim by whoever made it. A UK hallmark is the result of an independent assay office testing the metal and striking its own mark — which is why it is one of the few things on a second-hand piece that was verified by somebody with no interest in the sale.
It is also a legal requirement rather than a courtesy. Under the Hallmarking Act 1973 it is unlawful to describe an article as wholly or partly gold, silver, platinum or palladium at the point of sale, above the relevant weight, without a hallmark.
The weight thresholds
Below these weights, hallmarking is not compulsory — which is why fine chains, small earrings and light charms often carry no mark:
- Gold
- Compulsory at 1 gram and above.
- Silver
- Compulsory at 7.78 grams and above (half a troy ounce).
- Platinum
- Compulsory at 0.5 grams and above.
- Palladium
- Compulsory at 1 gram and above. Palladium was brought into the Act by a 2009 amendment.
The three compulsory marks
- Sponsor's mark
- The registered initials of the person or company that submitted the article for hallmarking, inside a shield. Two to five letters. It identifies who put it forward, not necessarily who made it.
- Millesimal fineness mark
- The precious-metal content in parts per thousand — 750 for 18ct gold, 925 for sterling silver — in a shield whose shape identifies the metal. This numeric format was introduced in 1999.
- Assay office mark
- Which of the UK offices tested and marked the piece.
The optional ones people mistake for compulsory
The date letter is optional, and has been since 1999. So is the traditional fineness symbol — the lion passant for sterling silver, the crown for gold — although some offices apply it as standard.
This matters when you are reading a modern piece: the absence of a date letter tells you nothing. On older pieces the date letter is usually there, and it is the part that lets you date the item.
The four UK assay offices
London (the Goldsmiths' Company Assay Office), Birmingham, Sheffield and Edinburgh. All four operate under the British Hallmarking Council, and a mark from any of them carries the same legal force.
Their town marks are the quickest way to place a piece: London uses the leopard's head, Birmingham the anchor, Sheffield the rose — Sheffield used a crown for silver from 1773 until the Hallmarking Act 1973 took effect, after which the rose applies to both silver and gold.
Marks from other signatory countries can also appear: a Convention Hallmark has four elements — the sponsor's mark, the Common Control Mark, the fineness figure and the assay office mark — and is legally recognised in the UK.
Checking a mark on something you are thinking of buying
Read it in four parts: who (sponsor's mark), what (fineness), where (assay office town mark) and when (date letter, where present). A photograph of the mark, sharp and straight on, is a reasonable thing to ask a seller for, and a seller who will not provide one has told you something.
The Goldsmiths' Company Assay Office in London will help identify marks: historic marks, pre-1975, through its Library team, and recent London marks through its registration team with photographs and a description.
One more signal: dealers are legally required to display the British Hallmarking Council's Dealer's Notice explaining approved hallmarks, including online. A trade seller who cannot point to one is not meeting a basic obligation.
When no hallmark is fine
Schedule 1 of the Act exempts a range of articles — items below the weight thresholds, articles manufactured before specified dates, coins, goods intended for export, raw materials and incomplete articles.
So a genuine antique or a very light modern piece can legitimately carry no UK mark. The absence of a hallmark is not evidence of a fake. What it does mean is that you have lost an independent check, and everything then rests on the seller.
Common questions
Does a hallmark prove the piece is by the brand it claims?
No. A hallmark certifies the metal and its fineness, not the maker. Brand attribution is a separate question, answered by the maker's own marks, serial numbers and paperwork — none of which is conclusive on its own either.
My pre-loved gold chain has no hallmark. Is it fake?
Not necessarily. Gold articles under 1 gram are exempt, as are various antiques. It does mean nobody independent has tested the metal, so on an expensive piece it is worth having assayed.
Are hallmarks from other countries valid in the UK?
A Convention Hallmark struck by a signatory country's authorised office is recognised in the UK. It carries four marks: sponsor's mark, Common Control Mark, fineness figure and assay office mark.
Where this comes from
Every figure and rule above is taken from the sources below. Rules, fees and brand practices change — check the source before you rely on it for a specific purchase.
- Hallmarking Act 1973
- Hallmarking Act 1973, Schedule 1 Part II — exempted articles and weight thresholds
- Goldsmiths' Company Assay Office London — What is a hallmark — 2026-09-19
- Goldsmiths' Company Assay Office London — Trace a hallmark — 2026-09-19
- Birmingham Assay Office — The Hallmarking Act 1973 — 2026-09-19
- Sheffield Assay Office — History and town marks — 2026-09-19
- Edinburgh Assay Office — Complying with the Hallmarking Act — 2026-09-19
- British Hallmarking Council — About — 2026-09-19
Put it into practice
Buying guides and live listings for the models this applies to most: