The London Assay Office — Complete Guide

The Worshipful Company of Goldsmiths has been assaying silver in London since 1300, making it the oldest continuously operating assay office in the world. Its leopard's head mark is the most widely recognised English silver hallmark — struck on Royal plate, Georgian tea services, Regency salvers and twentieth-century presentation pieces alike. Understanding the London hallmark is the single most useful skill for anyone valuing British silver.

This guide explains exactly what the London Assay Office is, what each of its punches means, how the date-letter system works, how to read the standard, duty and convention marks, and the most common pitfalls when attributing London silver. Throughout, we link to the relevant pages on our site so you can value or sell what you have.

A Brief History — Goldsmiths' Hall and the Leopard's Head

The 1300 statute of Edward I required every silver article offered for sale in England to be struck with the King's mark, a leopard's head, at Goldsmiths' Hall in London. Until 1478 this was the only assay mark required. The Goldsmiths' Company was granted its Royal Charter in 1327, which formalised its assay function. From 1363 silversmiths were obliged to add their own maker's mark beside the leopard, and from 1478 a date-letter was added — establishing the four-mark sequence (town, maker, standard, date) that has defined English silver ever since.

The leopard wore a crown from 1478 until 1821, when the crown was removed. Outside the City the office is still referred to by the trade simply as "London" or "the Hall" — and the leopard's head, crowned or uncrowned, is the single mark that confirms a piece was assayed there.

How to Read a Full London Hallmark

A complete London hallmark is a row of small punches struck on a discreet area of the piece — under the base of a teapot, on the rim of a salver, on the bezel of a snuff box. From left to right, the standard sequence is:

1. Maker's (sponsor's) mark — the silversmith or retailer's initials in a shaped shield.
2. Standard mark — a lion passant (sterling, .925) or Britannia figure (Britannia, .958).
3. Town mark — the leopard's head (crowned to 1821, uncrowned thereafter) confirming London assay.
4. Date letter — a single letter in a shaped shield indicating the year of assay.
5. Duty mark (1784–1890 only) — a sovereign's head, struck to show duty had been paid.

A full row of London hallmarks: maker's mark, lion passant (sterling), leopard's head (London) and date letter.

The Leopard's Head, Up Close

The leopard's head is the giveaway. On Georgian and earlier pieces it appears crowned, often within a slightly squared shield; on Victorian and later silver it sits uncrowned within an oval or shaped surround. The detail of the face, the mane and the punch outline are the easiest features to read on worn pieces — even when the date letter has rubbed flat, the leopard usually survives because of how its die was struck. Counterfeit pieces are routinely betrayed by an over-uniform, "printed" leopard with no relief.

London town mark: the leopard's head — crowned to 1821, uncrowned thereafter.

The Date Letter System

London changed its date letter every May (St Dunstan's Day, 19 May, was the trade's traditional turn-over). Each cycle runs through 20 letters of the alphabet (J is skipped), then the shield shape, letter style and case all change for the next cycle. That triple combination — letter, shape, font — is what dates a London piece exactly. Some well-known cycles:

A letter in isolation is rarely enough. You must match it to the shield shape and font cycle to date a London piece correctly — the same "A" appears every 20 years. Send us photographs of the marks and we'll date them for you.

Sterling and Britannia Standards

England has two recognised silver standards, both still assayed in London:

• Sterling — .925 (92.5% silver), marked with a lion passant. The dominant standard from 1300 onward.
• Britannia — .958 (95.84% silver), marked with a seated figure of Britannia. Compulsory in England from 1697 to 1720 to prevent silversmiths melting coinage; optional thereafter and still in use for high-quality presentation pieces. Britannia London silver also replaces the leopard's head with a lion's head erased.

Britannia-period (1697–1720) London silver is highly collectable — both for the higher fineness and the period craftsmanship of names such as Pierre Platel and the young Paul de Lamerie.

Duty Marks — The Sovereign's Head

Between 6 December 1784 and 30 April 1890, the British government levied a duty on hallmarked silver. The Assay Office added a fifth mark — a small profile of the reigning sovereign — to confirm the duty had been paid. Spotting which monarch on a London piece will pin its period instantly:

• George III — incuse and small to 1786, larger from 1786 to 1820.
• George IV — 1820–1830.
• William IV — 1830–1837.
• Victoria (young head) — 1837 to early 1890.

From May 1890 the duty mark vanishes. Post-1890 London silver therefore shows four marks, not five.

The Modern London Hallmark

The 1973 Hallmarking Act unified UK procedure, and from January 1999 the date letter became optional (most makers still use it). The 1999 Convention introduced an additional common control mark (a balance with scales) on silver intended for international trade. Since 2007 the millennium "M" mark has appeared on commemorative items. The London leopard's head remains the constant.

Notable London Silversmiths — A Specialist's Short List

The London Assay Office served the country's finest silversmiths. A few whose marks add significant value:

• Paul de Lamerie (1712–1751) — the finest rococo silversmith working in England. Anything by Lamerie is exceptional.
• Pierre Platel (Britannia period — Lamerie's master).
• Hester Bateman (1761–1790) and the wider Bateman dynasty — graceful, beautifully judged Georgian flatware and hollowware.
• Paul Storr (1793–1838) — the great Regency silversmith. Storr silver is consistently the top of the London auction market.
• Robert Hennell dynasty (later 18th to mid-19th century) — fine domestic silver.
• Garrard & Co — the Crown Jeweller; presentation pieces.
• Omar Ramsden (early 20th century) — Arts & Crafts hand-raised silver.

If your London piece carries any of these maker's marks, do not melt it — the maker premium is usually many times the silver value.

Pitfalls and Forgeries

• Cast hallmarks — a real London hallmark is struck with a steel punch and shows displaced metal at the edges. Cast or transferred marks look soft and recessed without surrounding metal flow.
• Re-let-in marks — a tiny disc bearing a genuine hallmark, soldered into a new (often plated) piece. Look for a faint solder line in a circle around the mark.
• Wrong cycle / letter mismatch — a leopard's head with a maker's mark that did not register until decades later is a clear giveaway.
• EPNS, silver plate, "EP", "A1" — these are not London marks at all. They are electroplate and contain no solid silver.
• Worn marks — wear is normal on antique pieces but the leopard usually survives because of the depth of the punch. If only one mark is legible, it is almost always the leopard.