The Singapore Assay Office (SAO), a division of Singapore Test Services Pte Ltd, is an independent certification body in Singapore that tests and certifies precious metal articles such as gold, silver, platinum and palladium for purity and content. In 1978, SAO achieved recognition as an Acceptable Assayer by the London Gold Market (now known as London Bullion Market Association). This award is only given when the highest levels of assaying expertise is attained.  

SAO provides the following services:

• Assaying of precious metals  
• Hallmarking Scheme for Jewellery Industry