By Rocco Clayfield, trading as GoldPaid; the business incorporated as GOLDPAID LTD (company 17382540) on 5 August 2026 · Published · updated
Found a stamp on your piece? Send us a photo of it
Photograph the number stamped inside the ring or on the clasp, then the whole piece, and send both on WhatsApp. We will reply with what the mark means and a rough estimate of what we would pay. No obligation, and nothing needs posting.
No WhatsApp? Call 07944 014111, 8am to 9pm.
Not sure what the mark says? Use the hallmark lookup. Final offers depend on inspection, item weight, purity, hallmarks, stones, non-gold components, condition and the live precious-metal market.
What a hallmark is for
A hallmark is the oldest form of consumer protection in Britain. A statute of 1300 required silver to be marked with the leopard’s head, and the Goldsmiths’ Company in London has carried out that work for centuries, as its history of hallmarking sets out. The system that followed grew across the kingdom and is now governed by the Hallmarking Act 1973. The marks tell you that an independent assay office tested the metal and confirmed it meets the standard claimed.
Without the assay office mark, a stamped "750" on a chain is a manufacturer’s assertion, not a legal certification. For a chart of the gold fineness numbers, including the 575 and 373 stamps that are not UK standards, use the UK gold hallmark chart and fineness table.
What are the three compulsory marks?
1) Sponsor mark. This is the maker, importer or sponsor of the piece. It is a unique punch registered with one of the assay offices. Usually two or three initials inside a shield or shaped cartouche.
2) Standard mark. The three-digit number that shows the parts per thousand of precious metal in the alloy. 375, 585, 750, 916, 990 and 999 for gold. 800, 925, 958 and 999 for silver. 850, 900, 950 and 999 for platinum. 500, 950 and 999 for palladium.
3) Assay office mark. The town mark of the office that tested the piece. The four UK offices are London (leopard’s head), Birmingham (anchor), Sheffield (a rose; Sheffield silver carried a crown until 1975), and Edinburgh (three-towered castle).
| Assay office | Town mark |
|---|---|
| London | Leopard’s head |
| Birmingham | Anchor |
| Sheffield | Rose (a crown on silver until 1975) |
| Edinburgh | Three-towered castle |
The optional fourth and fifth marks
Traditional fineness symbol. The crown for gold, the lion passant for sterling silver (a lion rampant on Edinburgh sterling), Britannia for Britannia silver, the orb for platinum and the head of Pallas Athene for palladium. Since 1999 these symbols have been optional extras struck beside the compulsory number, so a modern piece may not show one.
Weight thresholds you should know
The 1973 Act sets minimum weights below which an item is not legally required to be hallmarked. Gold below 1 gram, silver below 7.78 grams, platinum below 0.5 gram and palladium below 1 gram fall outside compulsory hallmarking. That is why tiny stud earrings, infant signet rings and thin charms may genuinely be solid gold but carry no assay office mark. The XRF report fills that gap.
A piece sold as precious metal that is above the threshold and is not hallmarked is either older stock made before the 1973 Act took effect in 1975, a foreign piece that has not been re-assayed for sale in the UK, or not actually the metal claimed.
Where to look on the piece
- Rings: inside the shank, near the bottom (the point of the ring opposite the stone). On heavy bands, on the inside surface where it sits against the finger.
- Chains: on the bolt-ring or lobster clasp, and sometimes on a small tag soldered next to the clasp.
- Earrings: on the post just below the back, or on the back of a stud.
- Pendants: on the bail (the loop at the top), or on the back face.
- Bracelets: on the clasp, or on the bar of the figure-of-eight safety catch.
- Pocket watches: inside the case-back, often with a separate sponsor mark for the case maker.
Common stamps that are not full UK hallmarks
"K", "Kt" or "KT" written after a number is a carat designation often used on US-imported pieces. "750" alone with no assay mark is a foreign or unhallmarked claim. "GF", "GP", "GEP", "RGP" and "HGE" are plating or rolled-gold abbreviations and not full standard marks. Numbers outside the British list, such as 333, 417, 583 and 875, are foreign standards that no UK assay office can strike: what 417, 333, 583, 585 and 875 mean on gold explains each one. A complete UK hallmark always has three punches: sponsor, standard, assay office.
What a postal buyer does with the hallmark
A hallmark is the starting point of the valuation. The XRF test is then used to confirm the alloy still matches the stamped standard. Mismatches happen, usually because a chain has been repaired with a different-carat solder, or because a counterfeit stamp has been applied to a base-metal piece. The XRF result is what the offer is paid against. If the metal does not match the stamp, the offer is calculated honestly against the metal that is actually there.
Your parcel travels on Royal Mail Special Delivery Guaranteed, tracked and signed for. Royal Mail cover may be available up to £2,500 depending on the postal method and cover level used. GoldPaid can confirm the appropriate postal option before you post. If the lot may be worth more than £2,500, tell us first and we can split it across more than one prepaid label at no charge. Final offers depend on inspection, item weight, purity, hallmarks, stones, non-gold components, condition and the live precious-metal market. See the full sell gold by post method.
Ten minutes with a loupe
You can do a lot with a 10x loupe, a kitchen scale and 10 minutes. Read the standard mark, locate the assay office mark, find the sponsor and date letter if present. The remainder is the metallurgy, which is what the XRF report exists for. Once you have both, you are negotiating with information, not guesswork. How the tested purity and weight are turned into an offer is the last step.