A country interested in becoming a Member or Associate Member of the International Mathematical Union is requested to read the IMU Membership Guidelines which provide general information about the IMU, details about IMU membership and associate membership, and explains how to apply for IMU membership or associate membership. Please contact the IMU Secretary General at secretary@mathunion.org for further information, if necessary.

Applications are supposed to be sent to the Secretary General of the IMU who will then present the case to the Executive Committee that will make a recommendation to the members of the Union. The IMU members will decide on the application by Postal Ballot or at a meeting of the General Assembly.

IMU has five groups of membership. Membership in Group n provides n votes in the General Assembly. The dues increase nonlinearly with the group number. For instance, the dues for group V are twelve times the dues for group I. The Statutes describe this more formally. The adherence of a country is in one of the five groups I-V with corresponding voting powers and contributions as set out in the Statutes. A country may change its classification with the approval of the members of the Union upon recommendation of the Executive Committee.