Turn over a ring you’ve worn for years, or look at the back of a pendant you were given, and you’ll usually find a row of tiny marks. Most of us never look at them closely. They’re worth reading, because they’re an independent record of what the piece is made of, struck into the metal itself.
A UK hallmark is applied by an independent assay office. It has three compulsory marks: the sponsor’s mark, the fineness mark and the assay office mark.
If you’re still choosing between metals, start with our guide to how to choose a metal. If you have a piece in your hand, here’s how to read it.
What is a hallmark, and why does it matter?
You can’t tell 9ct gold from 18ct gold by looking at it or holding it, and you can’t tell sterling silver from a silver-coloured lookalike either. So the law steps in. Under the Hallmarking Act 1973, gold, silver, platinum and palladium above a small exemption weight must be independently tested and hallmarked before they can be described as such.
The hallmark is your assurance that someone other than the seller has checked the metal. That matters most when you can’t easily check for yourself: when you’re buying a ring, insuring a piece or sorting through jewellery you’ve inherited.
What are the three compulsory marks?
| Mark | What it tells you |
|---|---|
| Sponsor’s mark | Who is responsible for the piece: the maker or business that sent it for testing, shown by their registered initials |
| Fineness mark | How pure the metal is, as a number out of 1,000 |
| Assay office mark | Which of the UK’s assay offices tested and marked the piece |
What do the numbers on a hallmark mean?
The fineness mark is the purity in parts per thousand. A 750 means 750 parts in every 1,000 are pure gold: 75%, or 18ct.
| Metal | Hallmark number | Purity |
|---|---|---|
| 9ct gold | 375 | 37.5% gold |
| 14ct gold | 585 | 58.5% gold |
| 18ct gold | 750 | 75% gold |
| 22ct gold | 916 | 91.6% gold |
| Platinum 950 | 950 | 95% platinum |
| Palladium 500 | 500 | 50% palladium |
| Palladium 950 | 950 | 95% palladium |
| Sterling silver | 925 | 92.5% silver |
| Britannia silver | 958 | 95.8% silver |
So 916 is 22ct gold rather than 24ct; pure 24ct gold is marked 999.
The number tells you the purity, never the colour: 18ct yellow, white and rose gold all carry 750. Platinum 950 and palladium 950 share a number, which is why each metal has its own outline around it. Palladium is the newest metal in the system; hallmarking it became compulsory in the UK in 2010.
Which assay office mark is on my piece?
The UK has four assay offices, each with its own symbol.
| Assay office | Symbol |
|---|---|
| London | A leopard’s head |
| Birmingham | An anchor |
| Sheffield | A rose |
| Edinburgh | A castle |
A mark from any of them carries the same legal weight; it only shows where the piece was tested.
What are the optional marks?
Some pieces carry extra marks beside the compulsory three:
- A traditional fineness symbol. For sterling silver, a lion passant (a walking lion) from the English offices or a lion rampant (a rearing lion) from Edinburgh, which used a thistle before 1975; for gold, a crown; for platinum, an orb; for palladium, the head of Pallas Athene.
- A date letter, which shows the year the piece was hallmarked.
Both have been optional since 1999, so some modern hallmarks carry only the three compulsory marks. On older pieces the date letter is often there.
How do you find and read a hallmark?
On a ring, the hallmark is usually inside the band. On a chain or bracelet, look on or near the clasp; on a pendant, on the back or on the loop the chain runs through. Read the number first, because it tells you the metal and its purity. Then find the assay office symbol, with the sponsor’s initials beside it.
Hallmarks are tiny. Look in good light, with a magnifying glass or your phone’s camera zoom.
Does every piece need a hallmark?
No. Very light pieces are exempt. A hallmark is required above these weights:
- gold: 1g
- palladium: 1g
- platinum: 0.5g
- silver: 7.78g
A small pair of stud earrings or a fine chain can fall below the limit. For pieces like those we run our own checks too: periodic voluntary testing of the lighter items, so they still meet the minimum fineness.
What if a piece has a number but no hallmark?
A number stamped on its own, such as 925 or 750 with no assay office mark beside it, isn’t a UK hallmark. The piece may have been made abroad, or it may be light enough to be exempt. The number may well be right, but nobody independent has confirmed it.
If you need to know, an insurance valuation includes identifying the metal: the valuer examines any marks and carries out appropriate tests to establish the metal and its fineness. Jewellery valuations explained covers how it works and what it costs.
How we check what we sell
Everything we stock goes through our own confirmation check before it’s sent out. Our commitment to hallmarking has the detail.
Read your hallmark with us
If you have a piece you can’t make out, bring it in and we’ll look at the marks with you: book a time with us in Ashford.
If it’s white gold that has started to look warm, the hallmark still stands; it’s the rhodium plating that has worn, as why white gold turns yellow explains. For everything else on metals, see our metals and hallmarks guide.
Frequently asked questions
Is jewellery without a hallmark fake?
Not necessarily. It may be below the exemption weight, made abroad, or so worn that the mark has faded.
Why is my gold-coloured jewellery stamped 925?
It’s most likely sterling silver with a gold finish. The hallmark describes the metal underneath, not the plating, so a gold-plated sterling silver piece is hallmarked as silver. It should be described as gold-plated sterling silver, never as gold.
Does a hallmark tell you how old a piece is?
Only if it has a date letter. Each year has its own letter, and you read it against a date-letter chart for the assay office that marked the piece.
Can a hallmark wear off?
It can wear faint. On a ring worn every day for many years, the underside of the band thins, and the hallmark inside it wears with it. The metal itself hasn’t changed, and the mark can often still be read under magnification.
Are Scottish and English hallmarks the same?
They carry the same legal weight; the differences are the assay office symbol, such as Edinburgh’s castle rather than London’s leopard’s head, and the traditional sterling silver symbol, if there is one.
