Hallmarking in the United Kingdom dates back more than 700 years and represents the oldest form of consumer protection in the United Kingdom.

This is the authorised stamp from an Assay Office, which is found on items of gold, silver and platinum. The hallmark indicates the authenticity and standard of the precious metal and shows that the item has been independently tested by one of the UK’s four Assay Offices in London, Birmingham, Sheffield or Edinburgh.

Precious metals are rarely used in their purest form but are usually alloyed with other metals. It is not possible to detect an article's precious metal content by sight or touch, therefore it is a legal requirement under the UK Hallmarking Act (1973) to hallmark articles containing precious metals if they are described as such.

A hallmark essentially indicates Who, What, Where and When:

The Sponsor’s (or Maker’s) Mark shows who made the article

The Fineness Mark guarantees the precious metal content

The Assay Office Mark shows where it was hallmarked

The unique letter mark for each year shows when it was hallmarked (not compulsory)