Gold Hallmarks Explained: The UK System

A hallmark is the oldest form of consumer protection in Britain. Long before advertising standards or trading law, it was the state's guarantee that a piece of gold was what it claimed to be. If you own a gold ring, chain or bangle made or sold in the United Kingdom, the small cluster of stamped symbols inside it is a legal record of its purity, where it was tested, and who was responsible for it. This guide explains how to read that record.

Seven centuries of a guarantee

The system began in 1300, when a statute of Edward I required that gold and silver meet a defined standard and be tested by the "Guardians of the Craft", who marked approved gold with a leopard's head. It is generally recognised as the earliest form of consumer protection in England (The Goldsmiths' Company, History of Hallmarking). In 1327 the Goldsmiths' Company received its first royal charter, giving it authority over the standard of the metal and over the goldsmiths themselves (Goldsmiths' Company Assay Office).

The word "hallmark" is itself a piece of London history. From 1478 items were brought to the Goldsmiths' own building, Goldsmiths' Hall, to be assayed and struck, so the marks applied there became known as the marks of the Hall, the hall marks (The Goldsmiths' Company). The modern legal framework is the Hallmarking Act 1973, which came into force in 1975 and still governs the marking of precious metals in the UK today.

The three marks that must be there

Under the current law a UK hallmark on gold is made up of three compulsory component marks (Goldsmiths' Company Assay Office, UK Hallmarks):

• The sponsor's mark. This is the mark of the person or company that submitted the item for hallmarking, registered with an assay office so that responsibility for the piece can be traced. It is often loosely called a "maker's mark", but the correct term is sponsor's mark: anyone may register one, maker, manufacturer or seller, and it is the sponsor who submits the piece. Its real purpose has always been to fix responsibility rather than to name the manufacturer (Assay Office London).
• The fineness (millesimal) mark. A number in an oval that states the purity of the gold in parts per thousand. Because no two precious metals share the same numbers, this single figure tells you both that the metal is gold and exactly how pure it is.
• The assay office mark. The town mark of the office that tested and struck the piece. Only four assay offices currently operate in the UK: London, Birmingham, Sheffield and Edinburgh (Assay Office London).

Two further marks are optional. The date letter, a single letter denoting the year of marking, was compulsory for centuries but ceased to be a required part of the hallmark from 1 January 1999; many pieces still carry one, and it remains the key to dating an item. The traditional fineness symbol for gold, a crown, may also be struck alongside the millesimal number as a decorative nod to the older system.

Reading the fineness: what the number means

Gold purity in the UK is expressed in parts per thousand, which maps directly onto the more familiar carat scale. The legal UK fineness standards for gold are set out below (Assay Office London, BullionByPost, Gold Hallmarks):

You may also meet two historic standards that were withdrawn in Britain in 1932: 15 carat (625) and 12 carat (500). A ring marked 625 or 15ct can therefore be dated with confidence to before 1932, which is one small example of how the marks tell a story beyond simple purity.

The four assay office marks

The town mark tells you where a piece was tested. The four working offices and their symbols are (Assay Office London, Sheffield Assay Office):

• London, the leopard's head, the mark of the Goldsmiths' Company and the oldest of them all.
• Birmingham, an anchor. Birmingham and Sheffield were both established as assay offices by Act of Parliament in 1773.
• Sheffield, a rose.
• Edinburgh, a three-towered castle.

Older pieces may carry the marks of offices that have since closed, among them Chester, Glasgow, York and Exeter, and those marks can help place an item in both time and place.

How to read your own gold

Take a piece of your own gold and a loupe or a phone macro lens. Look on the inside of a ring's band, the clasp or a link of a chain, or the pin or edge of a brooch. You are looking for the small line of stamps. Identify the number first, that is your purity and your proof it is gold. Find the town mark to see where it was assayed. If a date letter is present, it will pin the year. A genuine British hallmark is a legal statement, not decoration, which is precisely why it is worth understanding.

If your gold is unmarked, worn beyond reading, or foreign and unfamiliar, that does not mean it is not gold. It means it needs testing rather than reading, and testing is exactly what we do. If you would like a piece identified, valued, or you are thinking of selling it, Chapman Gold can help, and there is no better place to start than understanding the marks it already carries.

Sources: The Goldsmiths' Company; the Goldsmiths' Company Assay Office (Assay Office London); Sheffield Assay Office; the Hallmarking Act 1973 (legislation.gov.uk); BullionByPost. Full links throughout.