Understanding UK Hallmarks
How UK hallmarking protects buyers and what the compulsory marks tell you.
The Assay Office: guaranteeing trust since 1300
All our jewellery is hallmarked by the Assay Office: your guarantee of quality and authenticity. Understanding the hallmark, at a glance.
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Why Hallmarking Exists
Precious-metal content cannot be reliably judged by colour or feel. UK hallmarking provides independent verification that an article meets the legal standard for the precious metal description being used.
The Three Compulsory Marks
A complete UK hallmark normally contains a sponsor’s mark, fineness mark and Assay Office mark.
- Sponsor’s mark - identifies the registered sponsor who submitted the article
- Millesimal fineness mark - records precious-metal purity in parts per thousand
- Assay Office mark - identifies the UK Assay Office that tested and marked the article
Optional Marks
A date letter can show the year of hallmarking and traditional symbols can also appear. These can be useful, but they are not required parts of every modern UK hallmark.
When Hallmarking Is Compulsory
Subject to statutory exemptions, compulsory hallmarking applies when articles described as precious metal meet or exceed these metal-weight thresholds: gold 1g, silver 7.78g, platinum 0.5g and palladium 1g.
The threshold relates to the precious-metal content, and other exemptions can apply to particular categories of article. When in doubt, the current Hallmarking Act guidance and Assay Office information should be checked.
Recognised International Hallmarks
The UK also recognises qualifying Convention hallmarks from countries participating in the International Convention on Hallmarking. A recognised Convention hallmark can avoid the need for re-hallmarking in the UK.
Frequently Asked Questions
Does a hallmark tell me the retail value?
No. It verifies precious-metal fineness, not market value, design quality or stone value.
Does every gold item need a hallmark?
Not every item. Weight thresholds and other legal exemptions apply.
How many UK Assay Offices are there?
Four: London, Birmingham, Sheffield and Edinburgh.
Is the date letter compulsory?
No. It has been optional since 1999.
What are the three compulsory UK hallmark elements?
Sponsor’s mark, fineness mark and Assay Office mark.
Ask Gold Factory If you would like help applying any of this information to a real piece of jewellery, visit us at 294 Farnham Road, Slough, SL1 4XL, call 01753 536800 or contact us through www.goldfactory.co.uk. Jewellery can vary, so our team can explain the options for the actual item you are considering. |
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