Hallmark Guide

How to Read a British Hallmark

A simple, step-by-step method for reading a UK hallmark on any piece of gold jewellery — the sponsor mark, the fineness (such as 585 for 14ct/14K), the assay office mark, and where to find them. On a Majestic Jewellery piece, the sponsor mark reads CMJ.

Step-by-step method Where to find it Main Hallmark Guide
Sponsor mark Fineness Assay office mark

Reading order

  1. Sponsor (maker's) mark
  2. Fineness mark
  3. Assay office mark
  4. Optional marks (if present)
Assay Office Symbols Guide Use this page to identify which Assay Office tested the piece

Step-by-step: how to read a hallmark

1

Find the sponsor mark

The sponsor mark identifies the company responsible for submitting the piece for hallmarking. It is usually a short set of initials in a shaped outline — for example, on a Majestic Jewellery piece it reads CMJ.

2

Read the fineness mark

The fineness mark is the purity expressed in parts per thousand — for example 585 for 14ct/14K, 375 for 9ct and 750 for 18ct.

What 14ct/14K purity means
3

Identify the assay office mark

The assay office mark shows which authorised Assay Office tested and applied the hallmark. Majestic pieces are hallmarked at the London Assay Office (leopard's head).

Go to Assay Office Symbols Guide
4

Check for optional marks

Some pieces include optional marks (for example, a date letter). Not all hallmarks include optional elements.

Where to find the hallmark on jewellery

Hallmarks are often placed where they are protected from wear but still accessible for inspection. Location varies by jewellery type.

Ring

Commonly inside the band. On slimmer bands it may be compact and shallow, so use angled light.

Typical placement
Inside the band

Chain / Necklace

Often near the clasp, on the tag, or on a flat section of the fastening.

Typical placement
Clasp / tag area

Earrings

Commonly on the post, the back, or a small plate on the setting depending on the design.

Typical placement
Post / back / setting plate

Tip: use a phone flashlight from the side and zoom in. Hallmarks are often easiest to read with angled light.

Common mistakes (what to watch for)

Confusing "numbers" with hallmarks

Some items have internal stock codes or size marks. A UK hallmark is a set of marks, not a single random number.

Assuming any stamp equals official hallmarking

Official UK hallmarks are applied by authorised Assay Offices. A lone "14ct" or "14K" stamp may be a description, not an official hallmark.

Expecting perfect readability on very small pieces

On small surfaces, marks can be compact and lighter. Use angled light and magnification before concluding it is missing.

Missing the office mark

The office mark can be the hardest to spot. Use the dedicated symbols page to identify it accurately.

Assay Office Symbols Guide

Related Hallmark pages

Main Hallmark Guide Hallmark overview, the three compulsory marks and full purity table Assay Office Symbols Guide Identify the leopard, anchor, rose and castle office marks