Gold hallmarks explained for charity shops.

A UK gold hallmark is the official record of what an item actually is. It tells you the purity (9ct, 14ct, 18ct, 22ct), it tells you which assay office certified it, and on items hallmarked between 1855 and 1998 it also tells you the year. Once you can read three small parts of a hallmark (the purity stamp, the assay-office mark, and the optional date letter), you can identify almost any UK gold item you'll see in a donation. The rest is detail. This guide is written for charity shops, which means it focuses on the marks that turn up most often in donated jewellery, not the full history of UK hallmarking.

A hallmark is not a manufacturer's stamp. The manufacturer's stamp is called a sponsor mark or a maker's mark, and it's separate. The hallmark is the official, government-backed certification that the metal in the item is what it claims to be. UK hallmarking has existed in some form since 1300 and is administered by four assay offices: London, Birmingham, Sheffield and Edinburgh.

Items below a small weight threshold (currently 1g for gold) are exempt from compulsory hallmarking, which is why some genuine gold items, particularly small modern pieces, may not carry a UK hallmark. Imported items often carry their country-of-origin marks instead.

For charity-shop purposes, you don't need to memorise the history. You need to recognise three things on a mark:

1. The purity stamp.
2. The assay office mark.
3. The date letter (where present).

Get those three and you've identified the item.

The most useful purity stamps to recognise.

9ct gold (375)

9ct is the most common gold purity in UK jewellery. The "375" is the same thing in numerical form (the metal is 375 parts per thousand gold, or 37.5%). On older items you'll see the words "9ct"; on newer items the number "375".

Most 9ct pieces in charity donations are British post-war jewellery: wedding bands, signet rings, chains, brooches.

Note: 9ct is sometimes called "low-purity gold" in international markets, but it is genuine gold and has scrap value calculated from its 37.5% gold content. Don't dismiss 9ct because it isn't 18ct.

14ct gold (585)

14ct is less common in British-made jewellery but common in imports from continental Europe and the US. The mark is "585" (58.5% gold) or "14ct".

14ct pieces in UK charity donations are often US or European imports, or older British items from the inter-war period.

18ct gold (750)

18ct is common in higher-value British jewellery: wedding bands, engagement rings, signet rings, branded pieces. The mark is "750" (75.0% gold) or "18ct".

18ct is the most-asked-about purity in our charity inbox, partly because it's more visually obviously "gold" in colour and prompts charity teams to flag it.

22ct gold (916)

22ct is high-purity gold, common in South Asian wedding jewellery and traditional British wedding bands. The mark is "916" (91.6% gold) or "22ct".

22ct in charity donations often arrives via house clearance from South Asian families. The pieces can be substantial in weight and value.

Other purities you may see

• 24ct (999.9 or "fine gold"): pure gold, rare in jewellery, occasionally in bullion or modern fine-jewellery items.
• 10ct (417): a US standard, occasionally in donations of US-origin items.
• 15ct (625) and 12ct (500): historical British standards no longer used. Older Victorian and Edwardian items occasionally carry these.

If you see a purity stamp you don't recognise, photograph it and ask. We can identify most marks from a clear close-up.

The four UK assay offices each have a recognisable symbol. The symbol is stamped alongside the purity mark on hallmarked UK items.

London, the leopard's head

A small image of a leopard's head (technically a heraldic leopard, which is what you and I would call a lion with a face-on stare). London is the oldest UK assay office and the leopard mark has been used since 1300.

Birmingham, the anchor

A small anchor. Birmingham is the largest UK assay office by volume and stamps a huge proportion of British jewellery.

Sheffield, the rose (for gold)

A Tudor rose. Sheffield is best known for cutlery but assays both gold and silver. (For silver, Sheffield used a crown until 1975, and now uses the rose as well.)

Edinburgh, the castle

A three-towered castle. The Scottish assay office. Items hallmarked in Scotland carry the castle mark.

Recognising the four symbols allows a charity shop volunteer to identify the assay office at a glance. This is useful for two reasons. First, the assay office mark confirms the item is genuinely UK-hallmarked (rather than imported or unmarked). Second, certain assay offices are associated with certain item types, which can help estimate where and when an item was made.

A small letter inside a shield-shaped stamp indicates the year of assay. The system uses a 20-letter alphabet (A to U, skipping J), and the font and shield style changes each cycle so that no two years look identical.

Reading date letters precisely requires a reference table. The major assay offices publish their date-letter tables online and in printed reference books. You don't need to memorise them. What's useful to know:

• A date letter means the item is fully UK-hallmarked.
• The letter, combined with the font style and shield shape, identifies the specific year.
• For charity-shop purposes, a date letter is usually less commercially important than the purity and the maker's mark, but it can matter for antique items.

If a charity has a particularly old item (Georgian, early Victorian) where the date might add value, photograph the marks clearly and we'll identify the year and flag if there's any period-specific premium.

The fourth stamp you may see is the sponsor mark: usually two or three letters in a small shield. This is the registered mark of the maker or sponsor who submitted the item for hallmarking. For famous makers (Hester Bateman, Liberty and Co, certain Birmingham firms), the sponsor mark adds collector value.

For charity-shop purposes, the sponsor mark is worth noting because:

• A recognisable maker can increase the item's value above its scrap floor.
• It can identify a piece as part of a documented set (some makers used distinctive design vocabulary).
• It can authenticate the item where the marks are partially worn.

If you see a clear sponsor mark, include it in the photo when you send to WhatsApp. We'll identify recognisable makers and flag any premium.

A complete UK gold hallmark on a modern item will typically show:

1. The sponsor mark (the maker, in a small shield).
2. The fineness mark (375, 585, 750, 916, etc., in an oval).
3. The standard mark (a crown for gold, a lion for silver, note that the gold crown mark is being phased out for newer items).
4. The assay office mark (leopard, anchor, rose or castle).
5. The date letter (optional after 1998).

These five marks are usually clustered in a horizontal or vertical row, often small enough that a phone camera macro shot is needed to read them.

On older items the arrangement and mix can differ. Some Victorian items have a different layout, some early 20th-century items omit certain marks. The principle is the same: the marks together tell you what the item is.

A few specific things that catch charity volunteers and managers out.

"K" marks instead of "ct"

US-made items use the "K" designation: 10K, 14K, 18K. Same meaning as 10ct, 14ct, 18ct. The "K" comes from "karat", which is the US spelling of carat.

Items marked "GP", "GF" or "RGP"

These are not solid gold.

• GP = gold plated.
• GF = gold filled (a thicker layer than plate, but not solid).
• RGP = rolled gold plated.
• HGE = heavy gold electroplate.

Treat these as costume for scrap purposes. Some gold-filled items can have small recoverable value if heavy enough, but the per-gram economics rarely justify processing.

Marks that look like hallmarks but aren't

Some costume jewellery carries decorative stamps that resemble hallmarks (a small symbol, sometimes a letter). If the stamp doesn't include a recognisable purity number (9ct, 14ct, 18ct, 22ct, 375, 585, 750, 916), it isn't a UK hallmark. Photograph it and ask.

Worn-down marks

Long-worn rings often have hallmarks worn almost flat. The marks are usually still readable under macro flash. If you can pick out even one element (a number, a recognisable symbol), photograph it and we can often identify the rest.

Asian gold marks

22ct South Asian gold may carry the 916 mark plus other regional stamps (BIS Hallmark in India, country-of-origin marks). Items often have multiple smaller marks rather than the British four-shield cluster. The 916 is the key identifier.

For a back-room volunteer or manager, the practical routine is:

1. Pick up the item, turn it over, look for marks.
2. Use phone macro mode and flash to photograph any marks you can see.
3. If you can read a purity stamp (9ct, 18ct, 22ct, 375, 585, 750, 916, etc.), the item is almost certainly gold of that purity. Flag.
4. If you can read an assay office symbol or a date letter, the item is UK-hallmarked. Flag.
5. If you see "GP", "GF", "RGP" or "HGE", the item is plated. Price normally.
6. If you can't read any marks but the item feels heavy and well-made, flag anyway.
7. Send the photos on WhatsApp 07375071158.

That's the entire workflow. Two minutes per piece.

Rocco Clayfield, Director, GoldPaid.