With over a century of history, the precious metal assay and marking service is performed by accredited laboratories and specialised marking technicians, who apply the assay office marks and sponsor’s mark.
1248-1279 Reign of King Afonso III
Gold fineness was set at 9 dinheiros (18 carats or 750 parts per thousand), and silver fineness at 11 dinheiros (917 parts per thousand)
The reign of King Afonso V saw the liberalisation of metals prices, established in the Afonsine Orders of 1446.
Silversmiths were set up in the city of Lisbon, with a hallmark of a ship with crows;Orders of 1460
Legal fineness was redefined to 18 carats for gold and 11 dinheiros for silver.
1502-1557 Reign of King João III
Gold fineness was increased to 24 carats (999 parts per thousand)
1689Lisbon Senate Chamber Statute, of 13 July
The metal assay function passed to local government officers, who marked pieces with stylised letter L for the Municipality of Lisbon
1691Municipal Assay Offices
The Lisbon Senate Chamber Statute, of 13 July, was extended to the entire kingdom
1881The standardisation of hallmarks for the whole country was decreed during the reign of King Luis.
1882Municipal assay offices were closed on 27 July 1882
Creation of the Lisbon and Porto Assay Departments, under the remit of the Mint and Stamped Paper Office
1886The Braga Assay Department was created.
1911The Braga Assay Department was closed.
1913Creation of the Gondomar Assay Department.
1932The three assay departments were re-dimensioned by the 1932 Assay Office Regulation (Decree 20740, of 11 January).
1938The designation of “Department” was removed from the Assay Offices on 8 August 1938, by Decree-Law no. 28902
1972The Convention on the Control and Marking of Articles of Precious Metals was signed in Vienna.
It was approved for ratification by Decree No. 56/82, of 29 April
1979Entry into force of the Assay Office Regulation: Decree-Law no. 391/79, of 20 September
New series of official punches is introduced
1986The INCM Assay Office Department
was created, including the Lisbon and Porto Assay Offices and the Gondomar Branch
Withdrawal of white gold and jewellery punches. Introduction of new finenesses. Provisions allowing for the recognition of European Economic Area assay offices
2015Approval of the Legal Regime for Goldsmiths and Assay Offices (RJOC)
Law no. 98/2015, of 18 August
2017First amendment to the RJOC
Decree no. 120/2017, of 15 September