The 3 Mandatory UK Hallmark Symbols
Under the UK Hallmarking Act 1973, any gold item over 1.0 gram sold in the UK must bear a statutory hallmark. A complete traditional UK hallmark consists of three mandatory marks plus optional historical marks:
- Sponsor’s (Maker’s) Mark: The unique initials of the manufacturer or importer inside a shield shape.
- Fineness (Purity) Mark: A numerical symbol inside an oval shape indicating fine gold parts per thousand (e.g. 375 for 9ct, 750 for 18ct).
- Assay Office Mark: The symbol of the UK Assay Office that tested and stamped the item (Leopard head for London, Anchor for Birmingham, Rose for Sheffield, Castle for Edinburgh).
UK Fineness Number Reference Table
| Karat | Fineness Mark | Gold Purity % | Traditional Symbol |
|---|---|---|---|
| 9ct | 375 | 37.5% | Crown & 375 |
| 14ct | 585 | 58.5% | Crown & 585 |
| 18ct | 750 | 75.0% | Crown & 750 |
| 22ct | 916 | 91.6% | Crown & 916 |
| 24ct | 999 | 99.9% | Fine Gold Stamp |
The 4 Active UK Assay Offices
- London Assay Office (Goldsmiths’ Hall): Symbolized by a Leopard’s Head. Operating continuously since 1300.
- Birmingham Assay Office: Symbolized by an Anchor. Founded by Matthew Boulton in 1773.
- Sheffield Assay Office: Symbolized by a Tudor Rose (formerly a Crown prior to 1975). Founded in 1773.
- Edinburgh Assay Office: Symbolized by a 3-turreted Castle. Operating since 1457.
Common questions
Can gold be sold by post in the UK if the hallmark is worn away?
Yes. GoldPaid tests every item using non-destructive X-ray fluorescence (XRF) spectrometry. Even if the hallmark is completely worn, missing, or erased through sizing, our XRF analyzer measures the exact precious metal purity.
What does a 375 stamp mean on a ring?
A 375 stamp signifies 9ct gold, meaning 375 parts per thousand (37.5%) of the metal alloy is pure fine gold. The remaining 62.5% consists of copper, silver and zinc.