Perfect hallmarks every time

As an Assay Office, our primary service is to guarantee the purity of precious metals by assaying and hallmarking articles of gold, silver, platinum and palladium in compliance with National and International regulations.

We’ve been hallmarking for more than 550 years, and our clients trust us to produce perfect hallmarks every time. Our technology and innovative approach have made us world leaders in hallmarking.

We have the equipment and systems to meet our clients’ needs and are able to apply perfect hallmarks by hand, automated press machine, or non-contact laser. We use non-destructive testing technologies, so you know your items will be returned in flawless condition.

Find out more about the purpose of hallmarking here

Hallmarks of a perfect hallmark


A hallmark should be clearly and evenly applied, with all detail legible. Under magnification, marks should be clearly readable, with no doubling or blurring. Laser marks should be clean with no traces of burn.


A hallmark should be in a logical position on jewellery or silverware, and look like it belongs there. It should run parallel to lines of the item and appear centred.


Good technique and consistent routines should produce excellent repeatability in both position and quality of hallmarks across a range of identical articles. Marks should be in the same position every time.


The tools used to support unfinished items during hallmarking should minimise distortion. On finished items, marking should leave no trace of distortion or bruising, even when applied with a punch. Good handling routines should maintain product finish.


If a product is unfinished and requires polishing, the hallmark should be deep enough to withstand the finishing process. If the item is finished, the hallmark should be deep enough to survive the everyday wear, leaving a permanent and enduring hallmark.

Why our clients choose us again & again

The Edinburgh Assay Office understands silversmiths and works closely with them to minimise production problems where hallmarking is concerned. My work comes back in such a good state that little needs to be done to tidy it up; a huge help. The EAO is an example of how to conduct a thriving business in a helpful and courteous manner.

Malcolm Appleby, Silversmith

Over the years I have dealt with the Edinburgh Assay Office, I have experienced exceptional service. The staff members are efficient, friendly and always willing to help.

A service that we request regularly is the next day turnaround, which is quick and hassle free. I would not hesitate to recommend this service to other organisations!

Sara Keegan, SWAG

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