Understanding Hallmark Date Letters

The date letter is the part of a British hallmark that can fix a piece to a single year. Every assay office struck a letter that changed annually, running through the alphabet in cycles; each new cycle used a different typeface, a different case, or a differently shaped shield, so the same letter never means the same thing twice. Read correctly, alongside the right assay office mark, it gives the year the piece was tested.

How the System Works

The London office introduced annual date letters in 1478 so that the wardens responsible for a substandard piece could be identified. Other offices adopted the same principle. Three things identify a date letter:

1. The letter itself - A, b, C and so on.
2. Its style - Roman capitals, lower-case Roman, Old English (blackletter), italic, script and so on.
3. Its shield - the outline around the letter: square, rounded, pointed-based, cut-cornered and so on.

All three must match a published table for the correct office. A lower-case Roman “e” in one shield shape at London refers to a different year from an “e” in another shape, and from any “e” used by Birmingham.

Cycles Differed by Office

Each office ran its own cycles, of different lengths, starting in different years:

• London generally used cycles of 20 letters, A to U, omitting J.
• Birmingham (from 1773) and Sheffield (from 1773) ran their own sequences. Sheffield’s early letters, from 1773 to 1824, didn’t run in alphabetical order at all, so they can only be read from a table.
• Edinburgh, Glasgow, Dublin and Chester each had their own cycles.

This is why the assay office mark has to be identified first: without it, there is no way of knowing which table to use. See What Is an Assay Office Mark?.

Why London Letters Span Two Years

Until 1975, the London date letter changed on St Dunstan’s Day, 19 May - St Dunstan being the patron saint of goldsmiths. Each letter therefore covers the end of May in one year to the middle of May in the next, which is why reference books give London dates as “1896-97” rather than a single year. Other offices changed their letters at different points in the year. Since 1 January 1975 every office has changed its letter on the same date.

The 1975 Uniform Cycle

The Hallmarking Act 1973 introduced a single date-letter cycle shared by all British offices from 1975, starting with a capital “A” for 1975 and running to “Z” for 1999. For post-1975 jewellery, the date letter can be read without knowing the office. Since 1999 the date letter has been optional, though most pieces still carry one.

Common Misreadings

• Choosing the wrong office’s table. The most frequent error. Identify the office mark first.
• Ignoring the shield shape. Two cycles can use the same typeface; the shield is what tells them apart.
• Worn letters. Polishing and wear soften serifs and shield outlines, making blackletter capitals especially hard to tell apart. Use a 10x loupe and good, low-angle light.
• Reading a letter that isn’t a date letter. Makers’ initials, import marks and pattern numbers can all look like a letter in a shield.
• Damage from resizing. Ring hallmarks sit on the shank, exactly where rings are cut and resized, so a ring’s date letter is often partly lost or sometimes duplicated by later marks.

Using a Date Letter Table

Pocket references such as Bradbury’s Book of Hallmarks print date-letter tables for every British office, arranged by office and cycle. Find the office first, then the typeface and shield, and only then look for the letter. If the letter, style and shield don’t all match one entry, treat the reading as uncertain rather than choosing the nearest fit. How to Use Hallmarks to Date Jewellery shows how the date letter fits into reading a hallmark as a whole.