The 21st CGPM in October 1999 created a new category of Associate for those States and Economies not yet Members of the Metre Convention (see Introduction to the MRA).

This decision is embodied in Resolution 3 of the 21st CGPM.

The procedure for a State or Economy wishing to become an Associate is as follows:

Contact is first made made with the Director of the BIPM
(Prof. A.J. Wallard, BIPM, Pavillon de Breteuil, F-92312 Sèvres Cedex; fax: +33 1 45 34 86 70).

An application is made to the Director of the BIPM by the appropriate government or other official body, expressing the wish of the State or Economy to be added to the list of Associates; this application to the Director may be made directly or through the Embassy in Paris of the State or Economy.

The first payment of an annual subscription is made to the BIPM.

Since one of the principal purposes of a State or Economy becoming an Associate is to be able to participate in the MRA, the above procedure is normally followed by the signature of the MRA by the Director of the national metrology institute (NMI) of the new Associate. According to the MRA, signature requires the approval of the appropriate government or other official body in the State or Economy in question, which in this case is likely to be the same body that approved the application to become an Associate.