All items (over certain weights) sold in the UK and described as being made from gold, silver, platinum or palladium must have a legally recognised hallmark. The law is set out in the Hallmarking Act 1973 (which has been amended and updated on various occasions).
If a precious metal item weighs less than a certain amount it is not compulsory to apply a hallmark. The minimum weight thresholds are:
- gold 1 gram
- silver 7.78 grams
- platinum 0.5 gram
- palladium 1 gram