Ordinary membership is open to companies resident in, but with shareholders outside the region, whose business or professional activities contribute to the economic development of those countries.

Associate Membership is open to companies with their place of control within one of the countries covered by the Association but who also have an office or offices in one or more of the other countries in the region.

Subscription rates are assessed by the Executive Committee, but relate in general to the scale of a member's operations in the country or countries concerned.