The sponsor's mark, fineness mark and the assay office mark are compulsory marks. The crown on gold, the lion passant for 925 silver, the Britannia mark for 958 silver and the orb for 950 platinum and the date letter in all cases are voluntary additional marks.
Date Letters Explained
January is always an exciting month as it's the time that we mark the New Year with a new date letter.
The same date letter is used by all four UK Assay Offices, changing on the 1st January each year since 1975, with the date letter becoming a voluntary mark from 1999.
A new typographic alphabet is also issued every 25 years. To avoid confusion letters that look similar are not used, which in the last set meant the omission of i and j. Each set features a new typeface, case and shield shape to ensure that each letter can only indicate one specific year.
When Sheffield Assay Office first marked articles back in 1773 the first date letter stuck was an E (after the Earl of Effingham) and were then varied irregularly each year until 1824, after which year they were arranged in alphabetical order, and at that time, the date letter changed in July. By 1824 the sequence of alphabetical letters and the change of cycle from lower case to upper case was also implemented.
The date letter is a non-compulsory mark but is very useful for dating objects and marking special occasions and is recommended by all of the UK Assay Offices.
Bradbury's Book of Hallmarks
If you want to find out more about date letters then the Bradbury’s Book of Hallmarks is an excellent guide. The new updated editions - 2023 in hardback and 2024 in paperback, are a great place to start, and available to purchase from Sheffield Assay Office. The current editions display the new date letter series until 2028
Get your copy of the Bradbury Book of Hallmarks here
Dealers Notice
With the new series of date letter marks introduced in January 2025, the dealers notice has also been updated to reflect the change.
As part of the Hallmarking Act of 1973, all retailers selling items of precious metal in their shops, instore or online, are required by law to display a Dealer’s Notice in a position where customers can easily see it, so they can understand what the different hallmarks mean and what to look out for when purchasing items made of precious metal.
The latest Dealer Notice can be downloaded as a PDF from the Resources section on our website.
Download the latest Dealer Notice here
A hard copy of the Dealer Notice can also be purchased from us by contacting Sheffield Assay Office on 0114 2312121.