What UK Gold Hallmarks Tell You About Your Jewellery's Value
Every piece of precious metal jewellery sold in the United Kingdom carries a set of tiny marks that reveal its purity, origin, and authenticity. These hallmarks are not merely decorative — they are government-backed guarantees, verified by independent assay offices, that tell you exactly how much pure gold your jewellery contains.
If you have ever wondered what that "375" stamped inside a ring means, struggled to find the marks on a necklace, or questioned why two gold items look similar but have very different values, understanding hallmarks provides the answers. For anyone thinking about selling gold jewellery, this knowledge is the foundation for understanding what your pieces are truly worth.
Britain's 700-Year Hallmarking System
Britain's hallmarking system is one of the oldest consumer protection schemes in the world, dating back to 1300 when King Edward I established the first regulations at Goldsmiths' Hall in London — the origin of the word "hallmark" itself.
Today, four assay offices continue this tradition: London (marked with a leopard's head), Birmingham (anchor), Sheffield (Yorkshire rose), and Edinburgh (castle). When you find a hallmark on your jewellery, you are looking at marks applied after independent testing by one of these institutions, guaranteeing the precious metal content to legal standards.
This matters directly when selling. Hallmarks provide the foundation for transparent, fair pricing. They eliminate guesswork, ensure you receive accurate valuations based on verified purity levels, and protect you from undervaluation. At South Coast Jewellers, our specialists have over two decades of experience reading and interpreting hallmarks — including rare maker's marks and historical assay office stamps that many generalist buyers simply cannot recognise. To understand how counterfeits try to replicate these marks, see our guide to spotting fake gold.
Gold Purity Numbers Explained
The most important marks on your jewellery are the purity numbers. These directly determine value because they tell you exactly what proportion of the metal is pure gold. For a deeper dive into how gold valuation works, see our complete guide to valuing gold jewellery.
375 — 9 Carat Gold (37.5% Pure Gold)
The 375 hallmark indicates 9ct gold, the minimum legal standard for gold in the United Kingdom. It contains 37.5% pure gold mixed with other metals such as copper, silver, and zinc, making it durable and affordable. This is the most common carat in British jewellery and is popular for everyday wear. Its market value is approximately 37.5% of the pure gold price per gram.
585 — 14 Carat Gold (58.5% Pure Gold)
Less common in the UK than in continental Europe and North America, 14ct gold offers a good balance of purity and durability. You will often find this hallmark on imported pieces or modern designs influenced by international trends. Its market value is approximately 58.5% of the pure gold price per gram.
750 — 18 Carat Gold (75% Pure Gold)
The 750 hallmark indicates 18ct gold, the premium standard for fine jewellery. Prized for its rich colour and excellent balance between purity and wearability, it is the standard choice for engagement rings, designer pieces, and high-end jewellery. Its market value is approximately 75% of the pure gold price per gram.
916 — 22 Carat Gold (91.6% Pure Gold)
22ct gold is a high-purity standard particularly popular in South Asian and Middle Eastern jewellery, especially wedding bangles and ceremonial pieces. It is softer than lower carat golds and more prone to scratching, but its high gold content makes it excellent from an investment perspective. Market value is approximately 91.6% of the pure gold price per gram. If you are considering selling higher-carat gold, our guide on the best time to sell gold can help you decide when to act.
999 — 24 Carat Gold (99.9% Pure Gold)
Virtually pure gold, 24ct is very soft and rarely used for everyday jewellery. It is the standard for investment bars, coins, and some speciality East Asian jewellery. Market value tracks the pure gold price almost exactly.
The Four Elements of a Complete UK Hallmark
A complete British hallmark typically includes four distinct marks, each providing different information about your piece.
1. The Fineness (Purity) Mark
The numbers described above — 375, 585, 750, 916, or 999. This is the mark that most directly determines value when selling.
2. The Assay Office Mark
A symbol identifying which office tested and verified the metal. London's leopard's head, Birmingham's anchor, Sheffield's Yorkshire rose, and Edinburgh's castle each have centuries of history. For antique pieces, recognising the assay office can help date the item and establish its provenance.
3. The Sponsor's Mark
Unique symbols — typically initials in a distinctive shape — identifying the manufacturer or the company that submitted the item for hallmarking. For items by renowned makers, the sponsor's mark can add significant value above the metal content alone.
4. The Date Letter
A letter indicating the year of hallmarking. Date letters follow specific alphabetical cycles that vary between assay offices, making precise dating possible with the right reference materials. This is particularly valuable for antique and vintage pieces, where age contributes to collectability and value.
Where to Find Hallmarks on Your Jewellery
Hallmarks are deliberately small and discreet, placed where they do not interfere with the appearance of the jewellery. Knowing where to look saves considerable frustration.
Rings
Check the inside of the band. This is the most common location. Use a torch to illuminate the inner surface and a magnifying glass or smartphone macro mode to read the marks clearly. Marks may also appear under decorative elements or on the shank near the setting.
Necklaces and Chains
Look near the clasp or fastening mechanism. Hallmarks are often stamped on the jump rings that connect the clasp to the chain, or on the clasp itself. Check both ends of the chain, as marks can appear on either side.
Bracelets
Examine the area near the clasp mechanism, on safety chains or extensions, and inside expandable sections. Flexible bracelets may have marks on individual links.
Earrings
Stud earrings typically have marks on the post or butterfly back. Hoop earrings may be marked inside the hoop, and drop earrings on the finding (the part that goes through the ear).
Brooches
Check the back of the brooch, near the pin mechanism, and along the edges of decorative elements. Victorian and antique brooches may have marks in unexpected locations.
Tools for Hallmark Hunting
An LED torch provides directional lighting for shadowed areas. A magnifying glass (ideally a 10x jeweller's loupe) makes small marks legible. A smartphone camera set to macro mode can capture marks for closer examination on screen. Gentle cleaning with warm soapy water and a soft cloth can reveal marks obscured by tarnish or dirt, but avoid aggressive cleaning methods.
What If Your Jewellery Has No Hallmark?
Not all jewellery is hallmarked, and the absence of marks does not necessarily mean an item is not gold.
Legal Exemptions
UK law exempts certain items from hallmarking requirements. Gold items weighing under 1 gram, silver items under 7.78 grams, and platinum items under 0.5 grams are all exempt. Pieces predating current hallmarking laws, items imported before modern regulations, and certain categories including some wedding rings are also exempt.
Foreign Jewellery
Jewellery made outside the United Kingdom may carry different marking systems. Many countries use purity numbers (750, 585) without the additional British assay marks. Some foreign jewellery carries no marks at all, despite being genuine gold.
Professional Testing for Unmarked Pieces
When hallmarks are absent, worn away, or illegible, professional testing becomes essential. Acid testing uses a touchstone and acids of known strength to determine purity. Electronic testing measures electrical conductivity to estimate gold content without damaging the item. XRF (X-ray fluorescence) analysis provides the most precise composition readings.
Unmarked pieces typically receive slightly lower valuations due to the additional testing required and the uncertainty factor, but genuine gold is genuine gold regardless of markings. A reputable buyer will test thoroughly and share results transparently. South Coast Jewellers brings professional testing equipment — including acid testing kits, electronic gold testers, and specialist tools — to every home-visit appointment, ensuring even unmarked or worn pieces receive an accurate assessment at no cost. You may also have hidden value in broken or unwanted gold that a specialist eye can uncover.
Red Flags
Be cautious of large, heavy pieces that carry no marks at all — items above the weight exemption should be hallmarked if made in the UK. Poorly formed or irregular stamp marks, markings that seem inconsistent with the item's apparent age or style, and claims of high purity without verification are all reasons to seek professional assessment.
How Hallmarks Directly Affect Your Gold's Sale Value
The Purity-Price Relationship
Higher carat gold contains more pure gold per gram and commands proportionally higher prices. Compared to 9ct gold as a baseline, 14ct gold is worth approximately 56% more per gram, 18ct gold approximately 100% more, and 22ct gold approximately 144% more. This is why identifying your hallmark accurately before speaking to any buyer is so valuable — it immediately tells you the ballpark of what your gold is worth.
The Hallmark Premium
Hallmarked pieces typically receive a 5-10% premium over unmarked equivalents of the same purity, because the verified purity reduces risk for the buyer and speeds up the assessment process. Clear, legible hallmarks lead to faster, more confident valuations.
Historical and Collectible Value
Date letters and assay office marks can add value beyond the precious metal content. An 18ct gold bracelet hallmarked London 1892 may be worth significantly more than the same weight of modern 18ct gold, because the hallmark establishes it as a genuine Victorian piece with collector appeal. Our guide to antique Georgian jewellery explores how period and provenance can multiply a piece's value well beyond its metal content.
Calculating a Rough Value
The basic formula for estimating your gold's melt value is:
Weight (grams) x Purity (as a decimal) x Gold Spot Price (per gram) = Approximate Melt Value
For example, a 750-hallmarked (18ct) chain weighing 20 grams, with gold trading at around 60 pounds per gram, would contain 15 grams of pure gold worth approximately 900 pounds at melt. A reputable buyer typically offers 85-95% of melt value for standard items. For more detail on this calculation, see our guide to valuing gold jewellery.
Beyond the Numbers: What Hallmarks Reveal About Craftsmanship
Assay Office Choices
Different assay offices have historical associations. Birmingham handles the largest volume of contemporary hallmarking. London has traditionally been the choice for prestigious pieces. Sheffield is strongly associated with silver and cutlery. Edinburgh marks Scottish pieces and Celtic designs. These associations can provide context about a piece's origins and market.
Sponsor's Marks and Maker Attribution
For antique and vintage jewellery, identifying the sponsor's mark can unlock significant additional value. Pieces by renowned historical makers — from Georgian goldsmiths to notable Victorian and Edwardian jewellers — command premiums well above their gold content. A professional buyer with specialist knowledge will recognise these marks and factor them into the valuation. This is exactly why expertise matters: unlike generalist buyers who simply weigh gold, South Coast Jewellers assesses each item individually, looking for maker, age, and condition premiums that can significantly increase your offer. If you have inherited jewellery with unfamiliar marks, our estate jewellery guide for families can help you understand the process.
Date Letters and Period Identification
Hallmark date letters allow precise dating, which helps place pieces within specific design movements. Victorian (1837-1901), Edwardian (1901-1910), Art Deco (1920s-1930s), and mid-century modern pieces each have distinct collector followings and value profiles.
Get Your Gold Hallmarks Read by an Expert
Understanding your hallmarks gives you a powerful starting point, but professional assessment considers factors beyond the marks alone — condition, craftsmanship, design, gemstones, maker attribution, and current market demand all influence the final valuation.
At South Coast Jewellers, we use professional testing equipment including electronic analysis and acid testing during every home-visit valuation, giving you a reliable and verifiable reading of your gold's purity at no cost. Our pricing is transparent, based on live London Bullion Market Association (LBMA) prices, and we offer immediate payment by bank transfer or cash — no waiting. We explain every hallmark, show you test results, and walk you through exactly how we arrive at our offer. For a full breakdown of the calculation, see how we calculate gold cash offers.
Whether you have a single ring with a mysterious stamp or a collection of inherited pieces you have never had assessed, contact us for a free, no-obligation valuation. We serve clients across Bournemouth, Poole, Christchurch, Southampton, Portsmouth, and the wider South Coast — see our full areas we cover — bringing professional expertise directly to your door. You may also find our guide to selling gold in Bournemouth helpful if you are comparing local options.