Assay offices are official and technical services that form part of the services offered by Imprensa Nacional Casa da Moeda. They are responsible for assaying and marking articles of precious metal, as well as for placing legal fineness hallmarks on these articles and carrying out other duties as set out in current legislation, with full independence from any other activities in the sector.
There are two assay offices in Portugal:
- Lisbon assay office;
- Porto assay office, which includes the Gondomar branch.
Interested parties may use the services of any assay office, regardless of their geographical location.