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All about Hallmarking

Hallmarking is something that most people have heard of, but that many of us don't know much about, so in this blog post we thought it would be useful to take a closer look at it. What is hallmarking, why is it useful, how does it work and what does it look like?

A jewellery appraiser inspecting a piece of jewellery using a loupe
Taking a closer look!

What is hallmarking?

In the UK (as in a number of other countries), hallmarking is a process of marking or stamping the precious metal used in any piece of jewellery or other object before it is sold. This serves to give assurances to the customer that the piece they are buying is genuinely made of the precious metal that the maker claims has been used (and at the level of purity that is being claimed), and is an important piece of consumer protection. Having jewellery hallmarked also makes it possible for the item to be traced in future and the provenance of it (including the identity of the original maker) demonstrated.

It is an offence to sell jewellery made of precious metals in the UK that has not been hallmarked and to still describe it as being made of the precious metal, unless the piece is under a certain weight. Selling un-hallmarked jewellery above the applicable weight threshold carries heavy fines and risks prosecution.

In practice what this means is that, for example, a piece of silver jewellery that should have been, but hasn't been, hallmarked cannot be described as being made from silver and can only be sold as ‘white metal’ or 'silver-coloured' metal and will therefore be indistinguishable from pieces made from cheaper materials. This will significantly affect the price that can be charged for that piece of jewellery, and will make it uneconomical to produce, which is an important element of the protection afforded to consumers.

All individuals or companies selling jewellery or other objects made from precious metals must also carry a statutory dealers' notice on their website or at events such as craft fairs: you may have seen this on jewellery stands in stores; you can find ours here.

A pile of gold jewellery
Hallmarking helps customers to differentiate between valuable pieces and cheaper imitations

Does all jewellery need to be hallmarked?

Not necessarily. Pieces made from base metals (copper, brass, aluminium and a number of other metals) do not need to be hallmarked, and pieces made from precious metals (silver, gold, platinum or palladium) are only legally required to be hallmarked if the amount of precious metal used is over a set weight threshold (7.78g for silver, 1g for palladium or gold, 0.5g for platinum). Although these weight thresholds might look quite low, the silver threshold is actually fairly generous - even a chunky solid silver ring is likely to be under 7.78g: all Tawbis Studios chunky rings are around 5-6g, for example, even in the largest ring sizes. There are also some other exemptions, for example for vintage jewellery over a certain age.

Can jewellery that is under the weight threshold still be hallmarked?

Yes, absolutely. The weight thresholds help to identify those pieces which must be hallmarked but the assay offices (see below) will happily hallmark any piece that can be assayed to prove its composition. The process of hallmarking adds to the timescales and cost of producing a piece of jewellery and for that reason with some of the underweight pieces we’ve made to date (particularly where they were made with an upcoming craft fair in mind) we opted not to send them off for hallmarking at the time. However, we are in the process now of getting any remaining pieces, particularly those made of solid sterling silver such as our textured rings, sent off for hallmarking.

How does hallmarking work?

Hallmarking is undertaken by an ‘assay office’. Assaying is the process of testing the purity of the metal in order to determine its qualification for hallmarking.

There are only four assay offices in the UK that can legally carry out hallmarking (London, Birmingham, Sheffield and Edinburgh), and the hallmarking work they carry out is done under the supervision of the British Hallmarking Council and enforced by trading standards. All four offices also offer other services in addition to hallmarking but their hallmarking work in particular is tightly regulated.

All of the assay offices offer two basic types of hallmarking: laser and punch struck. Laser hallmarking is exactly what it sounds like: a powerful laser is used to etch away an area of the metal to leave the imprint of the hallmark on the item of jewellery. A punch struck hallmark is the more traditional method and involves the use of a metal ‘punch’ being placed on the metal and then struck with a hammer to leave an indentation in the metal.

What does the hallmark tell me as the consumer?

The hallmark itself consists of a number of separate elements that together give important information on the history and composition of the piece of jewellery: three elements are required by law and tell the buyer:

  • who made the item, or at least who submitted it for hallmarking (the sponsors mark: each sponsor’s mark is unique)

  • what metal and purity level it is made from (the millesimal fineness mark)

  • which assay office tested and hallmarked the piece (the assay office mark)

In addition, many hallmarks will also include two previously-compulsory marks which are now optional: the date letter mark (which indicates the year in which the piece was hallmarked) and the traditional fineness mark (which serves a similar purpose to the millesimal fineness mark but is generally more recognised by consumers as it has a longer-standing tradition of being used).

Occasionally additional commemorative marks may be used to mark a specific year (for example, in 2012 an additional commemorative mark was used to mark the Queen’s Diamond Jubilee) but for the most part hallmarks will comprise the three compulsory marks, plus the date letter and traditional fineness marks.

Which Assay Office does Tawbis Studios use?

We are registered with the London Assay Office, which was the first hallmarking office in the world. The London Assay Office is also known as the Goldsmiths’ Company Assay Office and the Goldsmiths' Company has been hallmarking since 1300 and operating a dedicated assay office since 1478 so it has quite a pedigree and an impressive track record of world-leading expertise!

The Goldsmiths’ Company is one of the Great XII Livery Companies in the City of London and gained its royal charter in 1327, although it was recognised by King Edward I as early as 1300 in a statute passed by the King that specified that gold and silver of ‘a defined standard’ had to be marked with a leopard’s head and that the Goldsmiths’ Company was to supervise this process.

This leopard’s head symbol remains the Assay Office mark of the London Assay Office to this day.

London assay mark - a leopard's head in white on a black background
The London Assay Office Leopard. He's quite a fierce-looking fellow, isn't he?

In 1478 the first assay office was established in Goldsmiths’ Hall of the Goldsmith's Company, and this is actually where the term ‘hallmarking’ comes from, giving the London Assay Office mark an incredible weight of history behind it!

Why London?

The decision-making process that led to us choosing the London Assay Office was not a simple one, but took in to account a range of factors, including likely cost and turnaround time for the range of jewellery we were most likely to be making.

By choosing the London office, we feel we have the ability to get pieces hallmarked with minimal impact on cost or timescale for you, our lovely customers.

While Edinburgh may have seemed like a more logical choice, as it's our closest assay office and the only one in Scotland, we are not based close enough to any of the assay offices to be able to take items in personally, so whichever assay office we were going to use, we would have been sending items by post, making geography a less important consideration.

And we will admit, while not the primary factor in our choice of assay office, the incredible history of the London office is a nice added bonus!

What does a Tawbis Studios hallmark look like?

As outlined above, the exact hallmark will vary from piece to piece, particularly as regards the date letter mark. Most of our jewellery is .925 sterling silver, but is often combined with copper or brass, which will also change the nature of the hallmark that will be used.

The first symbol on our hallmark will be our sponsors mark, which as mentioned above is unique to us. Our mark consists of my initials (ACB) inside a rectangular shield with inverse rounded corners.

The next mark will be the traditional fineness mark. For sterling silver, this will be a lion facing to the left inside a rectangular shape with bevelled corners.

The third mark will be the millesimal fineness mark. For sterling silver (often referred to as .925 sterling silver as it is made of 92.5% pure silver and 7.5% base metal, usually copper) this will be the number 925 inside an oval shield.

The fourth symbol will be the Assay Office mark, in this case the leopard’s head symbol of the London Assay Office, which is shown inside a square shield with bevelled corners.

The fifth symbol will be the date letter mark. Each calendar year is assigned a unique letter/font/shield combination to form a unique and traceable mark. The 2020 mark is a lower-case 'v' in a sans-serif font contained in a rounded square shield (the example below shows the date letter mark for 2017).

Finally, for pieces that consist of a mixture of a single precious metal and one or more base metals, which is the case for a number of our pieces, provided the base metals are clearly distinguishable (usually by their colour) the word ‘metal’ will be stamped after the hallmark to indicate that the piece of jewellery contains elements made of a metal other than that being hallmarked.

If a piece of made of more than one precious metal or more than one standard of the same metal, then the lowest purity/preciousness of metal will form the basis for the hallmark.

Precious metals are categorised by the assay office, starting with the least precious, in this order: silver, palladium, gold and then platinum, and then by the degree of fineness within each metal. For example, in a silver piece which contains both sterling (.925) and fine (.999) silver, the piece will be marked as sterling silver; in a piece containing both gold and platinum, the piece will be hallmarked as gold, and so on. However, what’s called a ‘part mark’ may also be added to confirm the fineness rating of the more precious metal, alongside the hallmark of the lower rated metal.

More information on the various elements of a hallmark can be found on the assay office website.

I have a piece of Tawbis Studios’ jewellery that is underweight and has not been hallmarked. Can it be hallmarked retrospectively?


The way that the cost of hallmarking is calculated is based on the number of pieces that are sent off at any one time to the assay office (the cost consists of a one-off ‘packet fee’ for each batch sent, plus a cost per piece), so the fewer pieces sent off at any one time the higher the cost for each individual piece. This contributed to the decision not to send some of our one-off underweight pieces for hallmarking in the early days of Tawbis Studios, even though we've been registered for hallmarking from the start, as the cost per item would have been prohibitively expensive.

However, we have recently started creating larger pieces that legally require hallmarking, and have also now built up a stock of underweight pieces which can be included in the same packet for hallmarking, thus reducing the price per item.

Therefore, if you do not have a particular need to have a quick turnaround on getting the item hallmarked, it can be included in the next packet to be sent off: simply email us at to discuss your requirements.

If you do have a particularly quick turnaround in mind, it’s still worth getting in touch in case we have a packet almost ready to send off. If we don’t, we can then discuss what other options might be open to you.

Going forward, all of our new silver rings will be hallmarked as standard, as will most of our other sterling silver pieces, and as mentioned above we are now in the process of working back through our existing underweight pieces to have them hallmarked.

Unfortunately, we are unable to have pieces hallmarked that were not made by Tawbis Studios: as each sponsors' mark is unique it is important that this correlates to the maker of the piece, and without having been involved in its creation we would not be able to verify the fineness of the metal used in order to be able to send it for hallmarking.

When I buy a sterling silver necklace from you on a sterling silver chain, will the chain also be hallmarked?

Going forward, that will be the case, but we are currently in discussion with the assay office about the best way to do this. As we hand-cut all of our chain to length, we want to retain the ability to be able to offer you a choice of chain length, but this obviously impacts on our ability to get the finished chain hallmarked along with the pendant in advance of it being sold, and may have an impact on our timescales for getting a purchased item in to your hands. We have a number of options open to us, and are just exploring which is the best method for getting the chains hallmarked.

The pendants that we already have for sale are not yet hallmarked as they are underweight and in many cases have gemstones set in them already, which will need careful handling, but as far as is possible our aim is to also get these pieces hallmarked. In the meantime, we will clearly mark in the online shop which pieces are hallmarked as we start to get them coming back from the assay office.

If you see a piece you like in our store that is not hallmarked but which you would like to be hallmarked, please contact us at we may be able to re-make the piece for you in such a way that hallmarking can be easily undertaken (eg before the stone is set) or may be able to send the existing piece for hallmarking as part of the process of you purchasing it.

Any other questions?

Hopefully this blog post will have answered all of the questions that you didn't know you had about hallmarking, but we love hearing from you, so if you do have any others just drop us an email to and we'll answer them as best we can!

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