Reading hallmarks
How to read gold hallmarks
By the Sortwell team · Updated · 4 min read
Short answer: UK gold hallmarks show purity as a number in parts per thousand: 375 is 9 carat, 585 is 14 carat, 750 is 18 carat and 916 is 22 carat. Older pieces often show the carat instead, such as 9 and .375 or a crown and 18. The hallmark also has a maker's mark and an assay office mark, and often a date letter. Letters such as RGP or GF mean rolled gold or plate.
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Gold jewellery turns up in almost every home, and it's often worth more than people expect. To read the marks, you'll want a magnifying glass or your phone's camera. Look inside ring shanks, on the tag near a clasp, and on the inside of bangles and watch cases.
What the numbers mean
The Hallmarking Act 1973 sets out the legal standards. The number is the gold content in parts per thousand.
| Mark | Carat | Pure gold |
|---|---|---|
| 375 | 9 carat | 37.5% |
| 585 | 14 carat | 58.5% |
| 750 | 18 carat | 75% |
| 916 | 22 carat | 91.6% |
| 990 | Almost pure | 99% |
| 999 | Pure gold | 99.9% |
The shape around the number shows which metal it is, so a gold mark has a different outline from a silver one.
The full set of marks
A modern UK hallmark has three required marks:
- A sponsor's mark, usually initials, showing who sent the piece for testing.
- The fineness mark, which is the number.
- An assay office mark, which shows where it was tested. A leopard's head is London, an anchor is Birmingham, a rose is Sheffield and a castle is Edinburgh.
The crown is optional, a pictorial extra you may or may not find. The date letter is optional too, and has been voluntary since 1999. Our silver hallmarks guide explains how to use a date letter, and the same system applies to gold.
Older gold marks
Before the modern system, gold marks changed several times. According to published histories of British hallmarks:
| Period | How gold was marked |
|---|---|
| Up to 1844 | 22 carat carried a lion passant, with no number |
| From 1798 | 18 carat carried a crown and the number 18 |
| From 1844 | 22 and 18 carat carried a crown and the number |
| From 1854 | 15, 12 and 9 carat carried the carat and a decimal, with no crown, such as 9 and .375 |
| From 1932 | 14 carat, marked 14 and .585, replaced 15 and 12 carat |
| From 1975 | The number in parts per thousand became the requirement |
A piece marked 15 and .625 or 12 and .5 must be from before 1932, which collectors can find useful. And because 22 carat was once marked with a lion and no number, an old piece of silver gilt can look just like gold. If an item has a lion mark and is gold in colour, have it tested before you assume anything.
Birmingham could only assay gold from 1824, and Sheffield from 1904. So a piece with a Sheffield mark and a date earlier than that can't be gold, however yellow it looks.
Marks that don't mean solid gold
Some stamps look official and aren't. If you see any of these, the piece is plated or rolled, with only a thin layer of gold:
- RGP, for rolled gold plate
- GF, for gold filled
- GP or EP, for gold plated or electroplated
- "9ct front" or "9ct back and front", where only part of the piece is solid
- "Metal core" or "metal bound", often on older bangles and lockets
A number on its own, without an assay office mark, isn't a British hallmark. It may be foreign gold that's perfectly genuine, but it hasn't been tested in the UK. Pieces of gold weighing under 1 gram don't have to be hallmarked, so small items and older jewellery can be unmarked and still real.
What's it worth?
For much gold jewellery, the weight and the carat set the floor. To work out melt value, weigh the piece, multiply by the purity and use the day's gold price. A buyer will pay less than this figure, so ask more than one and compare.
Some pieces are worth well above their gold content. Look out for antique jewellery in original condition, signed work from known makers, and pieces with good stones. Those are worth getting valued properly before anyone melts them. Jewellery you think may be worth £1,500 or more should be listed individually if the estate needs a full Inheritance Tax account.
When you're ready, our guide to selling antiques and inherited items compares your options.
Common questions
What is the hallmark for 9 carat gold?
Modern 9 carat gold is marked 375, meaning 37.5% pure gold. Older pieces may show 9 and .375 side by side.
What does 750 mean on gold?
It means 750 parts per thousand are pure gold, or 75%. That's 18 carat.
Is unhallmarked gold real?
It can be. Gold items under 1 gram don't need a hallmark, and much older or foreign jewellery has none. An assay office or reputable jeweller can test it for you.
What does the crown mean on gold?
The crown is a traditional symbol for gold. It's optional on modern hallmarks, and older British gold from 18 carat upwards often carries a crown beside the carat number.
Sources
- Hallmarking Act 1973
- Goldsmiths' Company Assay Office: UK hallmarks
- Goldsmiths' Company Assay Office: FAQs
- Sheffield Assay Office: History
- Vintage Watch Straps: British hallmarks
This guide is general information for people in England and Wales. The rules in Scotland and Northern Ireland can differ. It isn't legal, tax or financial advice, and Sortwell isn't a law firm or a valuer. If an estate is complicated or there's a disagreement, talk to a solicitor. Figures were checked on the date above.
Related guides
How to read silver hallmarks
What the lion, the town mark, the date letter and the maker's initials tell you, and how to tell real silver from plate.
How to sell antiques and inherited items in the UK
Auction, dealer or online: what each route really costs, and the rules on ivory and tax you should know before you sell.
How to value house contents for probate
What open market value means, what you can estimate yourself, when you need a professional, and how to fill in form IHT407.