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A beginners' guide to hallmarks


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Primary Item (H2)

Scrutinise any item of precious metal jewellery, and there's a good chance you will find a series of symbols stamped onto it. These hallmarks might as well be ancient Greek to the uninitiated, but once you understand them, they can tell you a great deal about the item you are holding.

Whether you're looking at engagement rings, wedding rings, or other items of jewellery, this article explains what hallmarking is, explores its history, its valuable role, and its drawbacks and limitations.

What is hallmarking?

Hallmarking is a form of consumer protection and quality assurance for precious metals, including gold, silver, platinum, and palladium. 

Different countries have different systems of hallmarking, but as a rule, hallmarking is performed by assay offices, which are authorised and regulated by national governments. 

These assay offices perform metallurgical tests (assay) of precious metal items to ascertain the purity of the metal in question before stamping or engraving the item to confirm the standard or fineness that it meets. 

This stamp or engraving is the hallmark, and it is this that provides assurance to consumers that the quality of the metal has been independently confirmed, therefore helping to protect against fraud and misrepresentation. 

A brief history of hallmarking

Hallmarking has a long and rich history. The word derives from Goldsmiths' Hall in London, where the Worshipful Company of Goldsmiths has their headquarters. Established in 1327, this guild of goldsmiths ensured the quality of gold and silver work produced within London and regulated the standards for the fineness of precious metals. 

However, there is evidence of rudimentary hallmarking dating back to the early centuries of the first millennium, before, in the middle ages, a degree of coherence (and bureaucracy) was brought to the process. 

Local governments began to take an interest in ensuring the quality of metalwork produced within their jurisdiction and employed authorised 'assayers' to inspect gold and silver goods before they could be sold. These Assayers would confirm that an article contained the minimum requirement of pure metal (initially, silver). However, they could not determine the precise purity of the metal due to the limitations of assaying techniques at the time.

In 1378, King Edward III of England passed the Statute of London, which required all gold and silver items to be tested and marked by the Worshipful Company of Goldsmiths to ensure their quality. This was the first time that hallmarking became a legal requirement, and it established the framework for a system of hallmarking that is still in use today.

Maker marks - an early example of corporate logos - were introduced halfway through the 14th century. A date-letter system followed in the 15th century, meaning that any piece could be dated at a glance.

Over the centuries, hallmarking has spread from England to other countries worldwide, with hallmarking laws and regulations being established in many countries to protect consumers and ensure the quality of precious metal items.

In the 19th century, hallmarking became more standardised with the introduction of international standards for fineness and the development of government-authorised assay offices to perform testing and certification. 

Despite the introduction of international standards for fineness, there is not a complete unified international set of hallmarking conventions, and so to interpret a hallmark, you need to know in which country the item was stamped. Full standardisation is unlikely in the short term because quality control varies widely between countries, and some countries are more rigorous at enforcing standards than others.

Hallmarking in the UK

UK hallmarking legislation

The Hallmarking Act 1973 and subsequent amendments and related legislation set out the legal framework for hallmarking in the UK nowadays and require that any items of silver, gold, palladium or platinum be hallmarked before sale to the consumer if they exceed the following weights:

Precious metalWeight
Maximum weight of precious metal allowed without a hallmark in the UK

UK assay offices

There are four authorised assay offices in the UK today:

However, in the past, there have been assay offices in several other UK towns and cities:

  • Norwich - closed in 1702
  • York - closed in 1858
  • Exeter - closed in 1883
  • Newcastle - closed in 1884
  • Chester - closed in 1962
  • Glasgow - closed in 1964

Components of UK hallmarks

A UK hallmark consists of four main components:

The Standard Mark

image 14
Left to Right: UK Standard Marks for sterling silver, 18ct gold and platinum 950

This indicates the fineness of the precious metal and is expressed as a number in parts per thousand. Set out below are the most common standard marks in the UK.

  • 375 (9ct gold)
  • 750 (18ct gold)
  • 925 (sterling silver)
  • 950 (platinum 950)

The Assay Office Mark

This symbol indicates the assay office that tested and certified the item. The office mark for the London Assay Office is a leopard's head, Birmingham is an anchor, Sheffield is a rose, and Edinburgh is a castle.

UK Assay Office Marks
UK Assay Office Marks

The Date Letter

UK hallmark date letters
UK hallmark date letters

in order to save space, a letter is used to indicate the year an item was hallmarked, and since 1975, all Assay offices have used the same date letter, which changes in January. The date letter for 2023 is y, and 2024 will be z.

Before 1975 it was more tricky to work out which year a date letter symbolised since different assay offices have used different lettering systems at various times and have not always run their hallmarking years concurrently. The Birmingham Office, for example, traditionally changed letters in July each year, while the London office used to change years in May.

The Sponsor's Mark

This is a unique symbol that identifies the manufacturer or sponsor of the item. The sponsor's mark for Ingle & Rhode is I&R.

Hallmarks on a wedding ring
A platinum ring stamped with the I&R sponsor's mark

In addition to the standard hallmarking components, other marks may be present on UK-hallmarked items, such as a national emblem or a design registration mark.

You can find out more about what a UK hallmark looks like here.

Pros and cons of hallmarking

Pros of hallmarkingCons of hallmarking
Consumer protection: Hallmarking provides assurance to consumers that the precious metal item they are purchasing is of the fineness or purity the seller claims.Cost: The hallmarking process adds to the cost of precious metal items due to the costs of testing and stamping.
Increased value: Hallmarked items can command a higher value as the buyer can be more confident that the metal is of the advertised quality.Bureaucracy: Hallmarking involves the involvement of government-authorised assay offices, which can lead to bureaucracy and delays in production.
Pros and cons of hallmarking


Hallmarking is the practice of testing the purity of precious metal items and then stamping or engraving them to confirm their purity. 

Rudimentary hallmarking emerged more than a thousand years ago, and was formalised in the fourteen century. Today, hallmarking continues to play an essential role in the precious metals market, providing assurance to consumers of the authenticity of precious metal items and protecting them against fraud and misrepresentation. 

Despite the clear advantages of having one unified international set of hallmarking conventions, no overarching standard exists.

In the UK, it is a legal requirement that all items of precious metal above certain minimum threshold weights are hallmarked, all hallmarking is performed at one of four assay offices (London, Birmingham, Sheffield and Edinburgh). The standard UK hallmark has four components: the standard mark (confirming the fineness of the metal), the date assay office mark (identifying where the items was hallmarked), the date letter (indicating when the item was hallmarked), and the sponsor's mark (identifying the manufacturer of the item).

David Rhode
Together with Tim Ingle, David created Ingle & Rhode to offer a better alternative to the traditional luxury brands. Since 2007, we’ve provided our customers with genuinely ethical engagement rings, wedding rings and fine jewellery – free from conflict diamonds, dirty gold and child labour. With more than 16 years experience in the jewellery industry, David has deep expertise in diamonds, gemstones and jewellery design and manufacturing.