UK Hallmarks Explained

A hallmark is a set of small marks struck or laser-engraved into a piece of precious metal, usually inside the band of a ring. It shows that the metal has been independently tested by an assay office and is at least as pure as it claims to be.

It is one of the oldest forms of consumer protection in the world. Standards for gold and silver in England date back to the year 1300, and the word itself comes from Goldsmiths’ Hall in London, where pieces were brought to be tested and marked.

The point is simple. You cannot tell 18k gold from 14k, or platinum from white gold, by looking. A hallmark means somebody independent has checked, so you do not have to take the seller’s word for it.

Under the Hallmarking Act 1973, it is an offence to describe an item as gold, silver, platinum or palladium when selling it in the UK unless it is hallmarked, or falls below the exemption weight for that metal.

Almost every engagement ring and wedding band weighs more than these thresholds, so in practice a gold or platinum ring sold in the UK should carry a hallmark.

A full UK hallmark has three compulsory parts:

The sponsor’s mark

Initials inside a shield, identifying the maker or the business responsible for sending the piece for hallmarking. No two sponsors share the same mark.

The fineness mark

A number giving the purity of the metal in parts per thousand, set inside a shield whose outline shows which metal it is.

The assay office mark

A symbol showing which of the four UK assay offices tested and marked the piece.

Optional marks may sit alongside them: a traditional symbol for the metal, such as a crown for gold or an orb for platinum, a date letter for the year it was marked, and occasionally a special commemorative mark.

The number is the one most people look for, because it tells you exactly what the ring is made of.

White, yellow and rose 18k gold all carry 750. The colour comes from the other 25% of the alloy, which the hallmark does not describe. Our gold vs platinum guide explains the difference between them.

There are four assay offices in the UK, each with its own mark:

All four test to the same legal standards. The mark tells you where the piece was tested, not where it was designed or made.

Look inside the band, usually at the bottom of the shank. On a fine ring the marks are tiny and often laser-engraved, so you may need a magnifying glass or a jeweller’s loupe and good light to read them.

If a ring has been resized, the hallmark may have been moved or partly lost in the process. A good jeweller works around it, and if a hallmark is ever removed, the piece can be re-marked by an assay office.

Shops that sell precious metal jewellery must also display the official Dealer’s Notice, which explains what each mark means. If you are buying in person, it should be on the wall.

Items imported into the UK must be hallmarked here before they are sold, or carry a Common Control Mark applied under the International Hallmarking Convention, which the UK recognises. A stamp of 750 or 18K on its own, without the other marks, is a manufacturer’s claim rather than an independent hallmark.

Hallmarking is one of the stages every Jabour ring passes through before it is finished, and the hallmark is recorded on the certificate that comes with your ring.