The International Association of Assay Offices (IAAO) is a forum for the exchange of information and promotion of technical co-operation between authorised state assay offices, with a view to provide a representative liaison body for communication with appropriate organizations.


Assay offices are bodies responsible for the assaying and hallmarking of precious metals, such as jewellery and silver ware.


The IAAO comprises 47 members from 37 countries. The IAAO works closely with the The Vienna Convention on the Control and Marking of Articles of Precious Metals. However, its membership is larger as not all members of the IAAO are members of the Convention.