The Electronic Guide to Assay Offices in the UK

Even the most experienced jeweller or chemist cannot tell how much precious metal there is in an alloy, just by looking at it, nor whether a thick plating of gold is covering a base metal interior. Due to the high price of precious metals, this offers a huge opportunity for fraud and there has therefore always been a need to protect the public, and honest suppliers, from those who are tempted to cheat them.

Subject to the provisions of the Hallmarking Act 1973, it is an offence to describe articles sold in the U.K. as being wholly or partly made of GOLD, SILVER, PLATINUM or PALLADIUM unless they are hallmarked or exempt. The hallmarking can either be a British Hallmark or a Convention Mark.

British Hallmarks after 1998 consist of a Registered SPONSOR'S Mark, a Standard Mark, and an Assay Office Mark. The complete range of finenesses that the U.K. Assay Offices can hallmark is as follows:

Metal	Traditional Description	Fineness (parts/1000)	Standard Mark	Convention Mark
Gold	9 Carat	375
	14 Carat	585
	18 Carat	750
	22 Carat	916
		990
		999
Silver		800
	Sterling	925
	Britannia	958
		999
Platinum		850
		900
		950
		999
Palladium		500
		950
		999

British Hallmarks prior to 1999 consist of a Registered SPONSOR'S Mark, a Standard Mark, an Assay Office Mark and a Date Letter.

There are four independent Assay Offices in the U.K. - London, Birmingham, Edinburgh and Sheffield. The British Hallmarking Council is the co-ordinating body. The Ministry responsible for hallmarking regulations is the Department of Trade and Industry (DTI).

For more information about Assaying in the U.K. we have articles that deal with the historical background to Assaying and a brief description of the Assay Office's Operations.