UK Hallmarking ActCurrent hallmarking requirements come under the UK Hallmarking Act 1973 and subsequent amendments. The Act is built around the principle of description, where it is an offence for any person to apply to an unhallmarked article a description indicating that it is wholly or partly made of gold, silver or platinum. There is an exemption by weight: compulsory hallmarks are not needed on gold under 1g, silver under 7.78g and platinum under 0.5g. Also, some descriptions are permissible, such as rolled gold and gold plate.
The four assay offices at London, Birmingham, Sheffield and Edinburgh operate under the Act.