The marks inside a UK hallmarked ring tell you who submitted it for testing, what precious metal it is and how pure that metal is, and which assay office tested it. Those three marks are compulsory, and you may also see optional extras such as a traditional symbol for the metal or a letter showing the year.
The marks are tiny, so a loupe or a phone camera on zoom helps. Here is how to read them one by one.
1. The sponsor's mark
This is usually a set of initials inside a shaped shield. It identifies the company or person who sent the piece to the assay office, often the maker or the retailer. Each sponsor's mark is registered, so it can be traced back.
2. The fineness mark
This is a number inside a shape, and it shows the purity of the metal in parts per thousand. The shape of the surround tells you which metal it is.
| Number | Metal | Also known as |
|---|---|---|
| 375 | Gold | 9ct |
| 585 | Gold | 14ct |
| 750 | Gold | 18ct |
| 916 | Gold | 22ct |
| 950 | Platinum | Platinum 950 |
| 950 | Palladium | Palladium 950 |
| 925 | Silver | Sterling silver |
Because platinum and palladium can both be 950, the shape around the number matters. Our 9ct vs 18ct gold vs platinum guide explains how those purities affect everyday wear.
3. The assay office mark
This symbol shows which of the UK's four assay offices tested and marked the piece.
- London: a leopard's head.
- Birmingham: an anchor.
- Sheffield: a rose.
- Edinburgh: a castle.
Optional marks you might see
Alongside the compulsory marks, some pieces carry extra symbols.
- Traditional fineness symbols. A crown for gold, an orb for platinum, the Greek goddess Pallas Athene for palladium, and a lion passant for sterling silver.
- Date letter. A letter in a shield showing the year the piece was hallmarked. It has been optional since 1999, so many modern rings do not have one.
- Common Control Mark. The UK has been part of the International Hallmarking Convention since 1972. Pieces marked by a member country with the Common Control Mark, a pair of scales, alongside the fineness and assay marks, are recognised in the UK.
- Commemorative marks. Special marks are sometimes offered for national occasions, such as a coronation or jubilee.
Photo: Walter Ipiña via Pexels.
Marks that are not UK hallmarks
Stamps such as "18K", "750" on its own without a surround, or "PT950" are often added by makers, especially abroad. They are a claim by the maker rather than an independent test. A UK hallmark means an assay office has tested the metal.
You may also see other engraving inside a band, such as a date or initials added for the wearer. These are personal, not part of the hallmark.
Does every ring have to be hallmarked?
In the UK, items sold as gold, platinum, palladium or silver generally need to be hallmarked unless they fall under the legal weight exemptions. The exemption weights are 1 gram for gold, 1 gram for palladium, 0.5 grams for platinum and 7.78 grams for silver, so pieces under these weights can be sold without a hallmark. Our guide to UK hallmarking covers the rules and the history.
Where to find the marks on a ring
On most rings the hallmark is struck or laser marked inside the band, usually at the bottom of the shank. On a very slim or fully set band it may be placed elsewhere, or marked by laser so it does not distort the metal.
Can a hallmark wear away?
Over many years, a struck hallmark can soften, and resizing near the mark can remove part of it. A good jeweller will try to keep the hallmark intact when working on a ring.
Hallmarked bespoke rings
Every ring we make is sent for UK hallmarking before it reaches you, so you can check the marks inside against this guide. Your design starts as a CAD render, and a 70% deposit starts the making once you approve it. Your ring is crafted by specialist goldsmiths, UK hallmarked and sent by insured tracked courier. Bespoke rings start from £600.
Read about the bespoke journey to see each stage, including hallmarking.
Frequently asked questions
What are the compulsory parts of a UK hallmark?
The sponsor's mark, the fineness mark showing metal and purity, and the assay office mark.
What does 750 mean inside a ring?
750 means the metal is 75% pure gold, which is 18ct gold.
What does an anchor mean on a hallmark?
An anchor is the mark of the Birmingham Assay Office.
Is 18K the same as a UK hallmark?
No. A stamp such as 18K is a maker's claim. A UK hallmark shows the metal has been independently tested by an assay office.