How to get an item hallmarked in the UK: the sponsor rule and the four assay offices

The four UK Assay Offices

The UK has four Assay Offices, each with its own town mark. All four are independently regulated, all four apply the same national fineness standards, and any UK-struck mark is legally equivalent to any other. The differences are geography, throughput, and specialisation.

• London Assay Office, Goldsmiths' Hall, London. Town mark: a leopard’s head. The oldest of the four: leopard’s head marking dates from a statute of 1300, and the permanent assay office at Goldsmiths’ Hall from 1478. thegoldsmiths.co.uk.
• Birmingham Assay Office, Moreton Street, Birmingham (relocated from Newhall Street in 2015). Town mark: an anchor. Established 1773. On its own published figures the largest by volume, serving the Jewellery Quarter trade. theassayoffice.co.uk.
• Sheffield Assay Office, Beulah Road, Sheffield. Town mark: a rose, used on gold from 1904 and on all metals from 1 January 1975; the crown was the Sheffield silver mark from 1773 until 31 December 1974. Established 1773 alongside Birmingham. Strong tradition in silver flatware. Assay Office Sheffield.
• Edinburgh Assay Office, Broughton Street, Edinburgh. Town mark: a three-towered castle. The only Assay Office in Scotland; Scottish hallmarking dates from an Act of 1457 and the castle mark from 1485. edinburghassayoffice.co.uk.

What legally has to be hallmarked

The Hallmarking Act 1973 makes it an offence to describe or supply an unhallmarked precious-metal item above the statutory threshold in the course of trade. The thresholds are per item, by metal.

Below those weights, hallmarking is not compulsory but is often still done. Above them, an unhallmarked item cannot lawfully be sold, offered for sale, or supplied as precious metal by a trader.

The sponsor rule: why you can’t walk in off the street

Every hallmark starts with a sponsor’s mark, a set of initials in a shield that identifies who submitted the piece for assay. The Act only permits Assay Offices to strike hallmarks on items presented by a person or company with a registered sponsor’s mark on file. Registering a sponsor’s mark is not difficult, but it means registering with an assay office on its own terms and fees. A private individual making a single ring for a wedding is not the target user.

In practice this means one of two routes:

• Go through a registered jeweller. Many working goldsmiths and bench jewellers are registered sponsors. They will submit your item under their own mark and usually add a handling charge to the Assay Office fee, so ask for the total before they send it.
• Register yourself as a sponsor. Sensible only if you are producing more than a handful of pieces a year. Registration terms and fees are set by each office.

What it costs, and where to check

Each assay office sets and publishes its own charges, and they change, so this page does not quote figures. Check the current list at the office you plan to use before anything is sent:

• Sheffield Assay Office hallmarking charges, with the current price list to download.
• Birmingham Assay Office hallmarking, which links its current price list.
• Assay Office London hallmarking steps: registration, the hallmarking note, delivery and payment.
• Edinburgh Assay Office, which you can contact directly for its charges.

If a jeweller submits the piece for you, their handling charge sits on top of the office’s fee.

When you actually need to arrange this

• You made the piece yourself and want to sell it as gold, silver, platinum or palladium in trade, through your own shop, at a fair, or online.
• You imported bullion or jewellery from outside the UK and want to sell it as precious metal in the UK. Foreign hallmarks may or may not be recognised under the International Convention on Hallmarks, check whether the origin country is a signatory before assuming.
• You had an old, unmarked piece tested and confirmed as precious metal, and you want to give it a legal mark before selling it on. This is uncommon but valid, a jeweller who is a sponsor can submit it on your behalf.
• You are commissioning a bespoke ring above the weight threshold and want it hallmarked for provenance and future resale.

You do not need to arrange hallmarking to sell inherited jewellery to a scrap or postal buyer, a scrap purchase is not a supply as precious metal in the Hallmarking Act sense, and the buyer will assay the piece on arrival regardless. If that is your situation, the practical route is on sell gold by post UK rather than the Assay Office.

What the marks look like once struck

A UK hallmark applied in 2026 will show, at minimum, three punches in a row: the sponsor’s mark, the fineness in its shaped surround (375, 585, 750, 916, 990 or 999 for gold; 925 for sterling silver; 950 for platinum; 500 or 950 for palladium), and the assay office mark (leopard, anchor, rose or castle). Many items also carry a date letter and the traditional metal mark, a crown for gold, a lion passant for sterling silver, an orb for platinum, a Pallas Athena head for palladium.

The full walkthrough of what those marks mean, with photos and shield shapes, is on the gold hallmark guide. A quick-read version is on how to read a gold hallmark in 60 seconds.

The one shortcut worth knowing

If the question underneath "should I get this hallmarked?" is really "how do I prove this ring is 18ct so a buyer doesn’t underpay me?", hallmarking is the slow expensive answer. The fast free answer is XRF: any reputable buyer will assay each item on arrival and put the fineness in writing on the offer. A hallmark makes that assay easier to trust before it is done, but it does not change the number. See XRF testing explained for the physics of it. If you want the metal checked without selling, a paid XRF metal test by post gives a written report and marks nothing.