One of the requirements of the Hallmarking Act 1973 makes it a legal requirement for persons who sell articles made of precious metals to display a notice explaining the approved hallmarks.

A hallmark is an official mark stamped on precious metal by British Assay Offices to certify its purity and origin. It protects the consumer by guaranteeing the metal content.

Designers who sell their work through Victoria Sewart Gallery each have their own hallmark, and it is applied where legally required.