About Us


We’ve been helping you make your mark since 1300.

The Goldsmiths’ Company Assay Office is where hallmarking began, and we have been testing and hallmarking precious metals for over 700 years. 

Our reputation for excellence in hallmarking, service, and support is both revered and unparalleled.

Our integrity is part of our heritage and is renowned.  Truth and transparency in what we do is vital, reflecting our historic company motto “Justice is the Queen of Virtues”. integrity likes at the heart of everything we do.

Swan neck punch, top, straight punch, bottom

The Assay Office Today

The skill of our teams honed over our remarkable history, our continuous investment in training, apprenticeship schemes and state of the art technology and equipment has made the London hallmark revered for its quality.  Our service is unrivaled and being part of the Goldsmiths' Company means we are committed to supporting the jewellery and silversmithing trade. Read about our Support for the Trade here

Now, we regularly hallmark 3 million articles each year.

In addition to our Goldsmiths’ Hall headquarters, we operate at a range of different sites, each situated to make life as convenient as possible for our customers. These include premises at Greville Street, in the centre of the Hatton Garden jewellery quarter and at Heathrow Airport, which provides a premium fully insured door-to door service for imported goods.


We also have a dedicated facility on the premises of the manufacturer Allied Gold based in Dalston, North London, as well as at the workshop of luxury jewellery retailer Graff Diamonds in Mayfair.