Step-by-step: how to read a hallmark
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.
Read the fineness mark
The fineness mark is the purity expressed in parts per thousand (e.g., 585 for 14K). Full karat/purity tables are kept on the main guide page.
See purity references on the main guideIdentify the assay office mark
The assay office mark shows which authorised Assay Office tested and applied the hallmark. Office symbol identification is kept on a separate page.
Go to Assay Office Symbols GuideCheck 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.
Chain / Necklace
Often near the clasp, on the tag, or on a flat section of the fastening.
Earrings
Commonly on the post, the back, or a small plate on the setting depending on the design.
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 “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