Hallmarks & Carats

London Assay Office: Goldsmiths’ Hall and the leopard’s head mark

The London Assay Office is run by the Goldsmiths’ Company at Goldsmiths’ Hall, and its town mark is the leopard’s head, which the statute of 1300 required on silver. The head was crowned from 1478 and has been uncrowned since the early 1820s. This page covers the office’s history; a separate guide covers identifying the mark on a piece.

By Rocco Clayfield, trading as GoldPaid; the business incorporated as GOLDPAID LTD (company 17382540) on 5 August 2026 · Published · updated

What does the London assay office mark look like?The London assay office mark is a leopard’s head. The statute of 1300 required it on silver; the head was crowned from 1478 until the early 1820s and has been uncrowned since. The mark is struck inside a shield-shaped punch alongside the sponsor mark, the standard mark and (optionally) the date letter. The Goldsmiths’ Company runs the office at Goldsmiths’ Hall in Foster Lane, where the permanent assay office dates from 1478.

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A short history of the mark

In 1300 a statute of Edward I required silver to be marked with the leopard’s head, called the king’s mark in early statutes. The earliest pieces show a striking, slightly snarling head facing forward. Through the 14th and 15th centuries the mark stayed forward-facing. It picked up a crown in 1478, the year the date letter was introduced, and lost it in the early 1820s. The Goldsmiths’ Company history of hallmarking gives 1822 and says the change was made without public announcement; other references give 1821.

Since the early 1820s the leopard has been uncrowned. Between 1697 and 1720, when the higher Britannia standard was compulsory, the leopard’s head was replaced by a lion’s head erased and the figure of Britannia. To read a leopard’s head on a piece in front of you, the London leopard’s head hallmark guide covers the variants and the marks beside them.

The Worshipful Company of Goldsmiths

The Goldsmiths' Company is one of the twelve great livery companies of the City of London. The permanent assay office at Goldsmiths’ Hall in Foster Lane dates from 1478. Today the office is a working laboratory: pieces submitted for assay are tested by XRF, fire assay or cupellation, then punched by hand or by laser if specified, then returned to the sponsor.

A London-assayed piece tells you the metal passed through that lab.

Reading the modern London hallmark

On a modern piece you will see four or five punches in a row: the sponsor (initials), the standard (a three-digit number), the leopard’s head, the date letter (optional from 1999), and a traditional pictorial mark if applicable. The leopard’s head sits inside a shield-shaped cartouche.
  1. Find the cluster of punches on the inside of the ring shank, the clasp of the chain, or the back of the pendant.
  2. Identify the three-digit standard mark first. It anchors the rest.
  3. Look for the leopard. It is small, in profile or facing forward, inside a shield. On worn pieces, look for the distinctive ear and crown line.
  4. Read the date letter if present. London uses a Roman or italic letter inside a shield that changes shape every 25 years on the current cycle. Since 1975 that letter has been shared with the other three offices, so it can be read straight off the table in hallmark date letters explained.
  5. Read the sponsor mark last, usually two or three letters in a rectangular punch.

Crowned versus uncrowned

The simplest dating cue: a leopard with a crown was struck before the early 1820s. Without the crown it is from the 1820s or later. Within those eras the head shape, the style of the cartouche, and the date letter narrow the year down further. A 15th-century forward-facing leopard is unmistakable next to a Victorian profile leopard, even on a tiny ring.

Where to look on common pieces

On rings, inside the shank at the bottom. On chains, on the bolt-ring or hidden tag. On pocket watches, inside the case-back, usually grouped with the case maker’s sponsor mark. On Edwardian and Georgian boxes, on the lip of the lid where it meets the body. On older flatware, on the back of the stem near the bowl.

What it means for postal valuation

A London hallmark gives a buyer two pieces of information at once: the metal was independently assayed by a major UK office, and the maker (sponsor) is a registered entity. The XRF test on arrival confirms the alloy still matches the standard. The offer is paid on the test result. Final offers depend on inspection, item weight, purity, hallmarks, stones, non-gold components, condition and the live precious-metal market.

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. The method is set out on the sell gold by post page.

Seven hundred years of one punch

The leopard’s head has been continuously punched onto British gold and silver for over 700 years. On any tray of jewellery from antique to modern, it is the mark you are most likely to find. Knowing how to read it turns an unfamiliar inheritance into a piece you can value with confidence.

Next step: have the mark checked against the metal

A hallmark records the standard a piece was assayed at. It does not tell you what the alloy measures now, what the piece weighs once stones and non-gold parts are set aside, or where the market sits today. Send a photo of the punches on WhatsApp and we will tell you what can reasonably be read from an image. Post the piece and it is XRF-tested on arrival, with a written offer showing the purity found, the weight and the figure for each piece. Decline it and the tracked return costs you nothing. Accept it and we aim to pay by Faster Payments within one working hour of your acceptance.

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Common questions

When did the London leopard lose its crown?

In the early 1820s. The Goldsmiths’ Company gives 1822 and many references give 1821; from then on the head is uncrowned.

Was the leopard ever replaced?

Between 1697 and 1720, Britannia and the lion’s head erased replaced the leopard on silver during the higher Britannia standard period.

Does London assay only stamp the leopard?

No. London marks gold, silver, platinum and palladium with their respective standard marks, plus the leopard as the town mark.

Can I send a London-assayed item by post for valuation?

Yes. Same method as any other piece. The hallmark helps with the initial inspection.

Is a forward-facing leopard older than a profile leopard?

Generally yes. The earliest marks were forward-facing. The mark moved through several profile forms over the centuries.

Are modern laser-applied marks accepted?

Yes. UK assay offices can apply marks by hand punch or by laser at the sponsor’s request. Both are legal.

What does the date letter look like?

A single letter inside a shaped shield. The shield shape changes every full alphabet cycle so the same letter has been used many times.

Does London assay sit inside the Goldsmiths' Hall?

Yes. The office is in Foster Lane in the City of London.

Not the question you had? The full GoldPaid FAQ covers the rest, from postal cover and ID checks to what happens if you decline the offer.

Related guides

Reference pages

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