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Hallmarking Guide


Hallmarking Guide

Want to know about jewellery hallmarks? What is a hallmark? How do you identify hallmarked jewellery? All this and more is answered in our jewellery hallmark guide.



Contrary to popular belief, simply the numbers ‘925’ on a silver piece of jewellery or ‘375’ on 9kt gold jewellery do not classify as a hallmark. These are simply just stamps which can easily be replicated by bad players.

A full UK hallmark is made up of 3 compulsory symbols & additional symbols which are optional. Under the Hallmarking Act of 1973, all precious metal jewellery sold in the UK bar notable exemptions are required to be hallmarked by a government approved Assay Office.

What are Hallmarks? Video courtesy of the British Hallmarking Council

It is illegal to sell unhallmarked precious metal items in the UK. Only a government approved Assay Office can hallmark jewellery or any other precious metal item and there are now only 4 Assay Offices in the UK. These Assay Offices are located in London, Birmingham, Sheffield & Edinburgh. Each of these Assay Offices have their own Assay Office mark which is a compulsory part of a full UK hallmark.

As precious metal jewellery is often alloyed with other metals to give it the strength required to craft jewellery from, it is impossible to tell by sight or touch the actual gold, silver, platinum or palladium content of the piece. The Hallmarking Act of 1973 offers protection to customers, assuring that the jewellery they buy is of the purity described by the retailer and verified as being of the purity described by one of these government approved Assay Offices.

What hallmarks are and what they look like…



Pieces of jewellery that are below a certain weight are exempt from hallmarking. The exemption weight is based on the weight of the precious metal in the piece. This does not include diamonds and gemstones in the piece.

The limits for each of the precious metals are:

  • Silver – 7.78g
  • Gold – 1g
  • Palladium – 1g
  • Platinum – 0.5g

Where To Find A Hallmark On Jewellery

Finding the Hallmark on a piece of jewellery is relatively easy. The location of the Hallmark of course depends on the piece of jewellery that you are looking at.

  • For pieces of jewellery that feature a chain with a clasp, the Hallmark is usually found around the clasp or the chain’s end caps. This is usually the first place you would check when looking for the Hallmark on a chain. This usually also applies to necklaces, bracelets and anklets.
  • For pendants, the Hallmark is usually located either on the back of the pendant or on the pendant bail.
  • For rings, the Hallmark is mostly located somewhere on the inside of the band.

Compulsory Hallmark Symbols

Sponsor Mark

This mark indicates the maker or sponsor of the item and represents the manufacturer or retailer who submitted the item for testing. In the UK this consists of at least 2 letters within a surround.

Sponsor Mark

Metal & Fineness (purity) Mark

This mark indicates the precious metal content of the piece and that it is not less than the fineness of the piece indicated. The fineness is measured in parts per thousand and the metal is indicated by the shape of the surround.

Metal & Fineness Mark

Assay Office mark

This mark indicates the particular Assay Office at which the piece was tested and marked. There are 4 Assay Offices in the UK – London, Edinburgh, Birmingham and Sheffield.

Assay Office Mark

Optional Hallmark Symbols

Date Letters

Date letters show the year in which the piece was hallmarked. Up until 1998, this mark was compulsory as part of a full UK hallmark.

Date Letters Mark

Traditional Marks

These marks are the traditional standard marks. Traditional marks can still voluntarily be used on pieces today.

Traditional Marks

Commemorative Marks

Commemorative marks are special hallmarks which celebrate special events. They can also be used a rough guide as to when the piece was hallmarked.

Commemorative Marks