UK Gold Hallmark Guide
How to identify real gold by its hallmark stamp.
What is a hallmark?
A hallmark is a set of tiny stamps on a piece of gold or silver that guarantees its purity. In the UK, the Hallmarking Act 1973 requires all gold items weighing over 1 gram to be hallmarked before they can be sold as gold.
A UK hallmark typically contains: the sponsor's mark (who made it), the fineness number (purity), the Assay Office mark (who tested it), and optionally a date letter.
The fineness number is the most important part for valuation — it tells you exactly how much pure gold is in the item.
Gold purity numbers
Most common UK gold. Used in everyday jewellery — chains, rings, bracelets, earrings. Harder and more durable than higher carats due to higher alloy content.
Standard in Europe and the USA. Less common in UK but found in imported jewellery. Good balance of purity and durability.
Fine jewellery and high-end pieces. Rich, warm colour. Softer than 9ct so scratches more easily. Common in engagement rings and luxury brands.
Traditional in Asian and Middle Eastern jewellery. Very soft and rich in colour. Gold Sovereigns and many gold coins are 22ct.
Pure gold. Too soft for jewellery — used for investment bars, coins (Britannias, Buffaloes), and some specialist items.
UK Assay Offices
Four Assay Offices in the UK test and hallmark precious metals. Each has a unique symbol stamped alongside the fineness number.