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All precious metals supplied in the UK must be hallmarked to prove they are as sold. There are three compulsory hallmarks, and many other optional marks that you may find on your jewellery. Anything manufactured before 1998 will have a minimum of four marks, and anything made since then will have at least three (the date mark is now optional).
Each item will show a sponsor's (maker's) mark, a standard mark to show the metal and the mark of the Assay office which tested and stamped the metal.

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The main thing people look for in their hallmark is the Standard Mark - the mark which verifies the metal. This will contain a number encased in one of many different shapes. Both of these factors together tell you the metal. The Sponsor's Mark will be in the form of initials, and the mark of the Assay Office will be a symbol. Other symbols or letters can tell you more about the history of the item and the metal.

Items under certain weights don't require hallmarks. Those weights are 0.5g for platinum, 1g for gold, and 7.78g for silver.

The Standard Mark

The number in the metal mark represents the standard of fineness, i.e. the purity of the precious metal in parts per thousand. To relate this to the carat, think of the carat as the parts out of 24. For example, 18ct gold is 18/24 gold, which is 750/1000, meaning it gets stamped with 750.

(375)-9ct     (585)-14ct     (750)-18c     (916)-22ct     (990)     (999)

White gold, traditional yellow gold, and rose gold all have identical hallmarks, as each fineness level contains the same proportion of gold (the colour difference comes from the other metals added to the alloy). The Assay office only test the proportion of gold rather than the other metals in the mix.

Silver fineness is shows inside an oval, showing one of four different standards. Sterling silver is 925, meaning it is 92.5% pure.

(800)     (929)-sterling     (958)-Britania     (999)

As with silver, there are four standards for platinum. The most popular in jewellery is the Platinum 950.

(850)     (900)     (950)     (999)

Palladium is relatively new to the jewellery market, and its hallmark only became a legal requirement in 2010. Before that, it had an optional hallmark of a trapezoid - the compulsory mark is like three overlapping circles.

(500)      (950)     (999)

The Sponsor's Mark (Maker's Mark)

The Sponsor's Mark used to be known as the maker's mark, and shows the person or company responsible for sending the item to the Assay Office. The Sponsor's Mark will be in the form of initials and may be the manufacturer, retailer, or importer, not necessarily the name of the company you bought the ring from.

The mark of the Assay Office

There are only four British Assay Offices.






Hallmarking: About Us


Optional hallmarks include the year, commemorative marks, duty marks or additional standard marks.

The Year Stamp

is in the form of a single letter; distinct by its background shape, font, and whether it's upper or lower case.


marks include such things as the millennium mark and the Queen's Jubilees.


marks indicate that the item was stamped in a year when a duty was placed on gold or silver by the Crown.

Historically, marks have been added to show that an item was of foreign import.

Other standard marks than the simple number/shape combination have been in an out of fashion over the years. All metals have other marks that can be added to show what they are, e.g. palladium often has the stamp of the Pallas Athene. Stirling silver used to come with a lion mark and gold with a crown or a sun icon.

Hallmarking: About Us
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