Currently there are only four British Assay Offices operating in the UK and these can be found in London, Sheffield, Glasgow and Birmingham. The Birmingham Assay office can be found at the Birmingham Jewellery Quarter sometimes misspelt as jewellry or jewelry, in Newhall Street, B3 1SB. A careful look, usually with a magnifying glass, at jewellery and items manufactured in special metals, like silver spoons, teaspoons, candlesticks, the numerous Georgian flatware patterns, cutlery sets, sugar shakers or shaker, antique Georgian teapot or teapots, teasets or teaset, thimbles or thimble, sugar tongs, caddy spoons, soup ladles or ladle, cruet sets, napkin rings, claret jug or jugs, inkwells, tea strainers, trays and tankards will quickly identify the hallmark and in turn the makers, such as Buccellati, Roger Brothers 1847, Georg Jennson, Hester Bateman, etc.

Hallmarking first came to fruition in the 1300 when Edward 1, through Statute, introduced the marking of precious metals, its objective being to protect the public against fraud and for the manufacturer, protection against unfair competition. Hallmarking is probably the earliest form of consumer protection as it is known today.  

The use of hallmark stamps provides information on the sponsor (manufacturer/makers, retailer, importer etc.) identified by the use of letters, the three numerical marks identify the purity and type of precious metal/metals used, gold, silver and platinum, the assay office where the item was tested, Birmingham testing is identified by the anchor, and the year when the item was actually tested and marked. Since 1998, however, the test year has been deemed as no longer obligatory.

Such markings cannot be carried out by the manufacturer, hence the need for Assay Offices. Such marks also provide great assistance when expert item valuation or valuations are carried out.

Items which are exempt from hallmarking are items which fall below the minimal weight requirement and these are items which are less than - gold 1 gram, silver 7.78 grams and platinum 0.5 grams.

Gold hallmark guide

.999 = 24 carat = 99.9% (Classed as Pure Gold)

.916 = 22 carat = 91.6%

.750 = 18 carat = 75%

.585 = 14 carat = 58.5%

.417 = 10 carat = 41.7%

.375 = 9 carat = 37.5%

.333 = 8 carat = 33.3%

Hallmarking is as important today as it has been since its initial introduction, mainly because precious metals are never totally pure when used in item manufacture as they are too soft and are always alloyed with copper or other metals to create a metal that is strong, workable and more importantly an attractive finished article. The alloyed metal must also meet with the requirements of the jeweller.  Due to the high value of the various precious metals there are serious profits to be made by reducing their content with base metals easily camouflaged by a thin coat of gold, silver or platinum, that is until the plating wears away and resilvering etc. is required. Even a jewellery expert or chemist would struggle to identify by eye, an items metal quality. 

There has, therefore, always been a need to protect the general public, honest retailers and suppliers from the fraudsters and deceptionists of this world. Hence the obvious reason for Hallmarking by assay experts who remove a tiny piece of the precious metal for testing and to determine if the alloys content meets the required hallmarking standard.

Other services provided by the assay office include laboratory or lab nickel testing, metal analysis, plating thickness determination, consultancy, loose gemstones, silver bullion and gold bullion certification. 

The Birmingham Assay Office opened on the 31 August 1773, following the petitioning of Parliament by Mathew Boulton, Birmingham's silversmiths and other great industrialists who joined forces with Sheffield manufactures to allow both Sheffield and Birmingham the right to assay sliver. At the time of the petition the only assay offices available to English manufacturers were in Chester and London and transporting items for assaying were costly with item damage along the rough and unsurfaced roads inevitable, plus thefts by the notorious highwaymen of the day.

Hallmarking today can be done by hand, by the use of hand or hydraulically operated presses and more recently by laser. It is obviously important that the hallmarking procedure is the most appropriate. This will be very much dependent on numbers, shape, size and material construction of the items being marked.

An assay office has its own jig making section which will produce hundreds of jigs to accommodate and support all shapes and sizes of articles received for marking purposes. This same section will also produce blank punches which are sent to accredited manufacturers to have the individual customers mark and the other required symbols machined into them.

Hallmarking has provided valuable protection for some 700 years plus. Such compulsory marking protects all parties, both wholesale & retail and more importantly provides the buying public with a guarantee of material quality.

The Birmingham Assay office is reputed to be the largest office in the World and in 2006 hallmarked in the region of 12,000,000 items, which was a slight drop from the 13,000,000 million figure recorded in 2003.