The ISI aims to facilitate collaboration among diverse groups of ISI members, statistical societies and other national and international organisations with statistical interests. 

The ISI provides two types of membership to cater to different individuals and organisations: 

1. Individual membership
   1. Regular Membership: Any individual can apply for regular membership in the ISI.
   2. Elected Membership: Regular members or potential new members can be nominated for elected membership. Elected members should have made significant contributions in statistical research, practice, education, administration of statistical service, or promotion of the profession. The nomination and election processes are specified in the By-laws.
   3. Ex-officio Membership: Each organisational member (described in the next section) is entitled to designate one person as an ex-officio member, who will have all the rights of individual membership. The details of ex-officio membership are not explicitly mentioned but can be inferred to apply to organizational members.

All individual members, regardless of the membership type, have voting rights. Regular and elected members are required to pay annual dues determined by the Council.

2. Organisational membership
   1. Institutional Membership: National, regional, and international statistical institutes/agencies, central banks, and private organisations may become institutional members of the ISI.
   2. Affiliate Membership: Any non-profit organisation, including national or regional statistical societies, may become an affiliated member of the ISI, subject to approval by the Executive Committee.

Each organisational member is entitled to designate one person as an ex-officio member (as mentioned earlier), who will have all the rights of individual membership.

The Executive Committee is responsible for making all final decisions on applications for membership.

Please note that the specific details and requirements for membership may be further elaborated in the ISI's By-laws or other official documents governing the organisation.

General Assembly

The General Assembly which is the highest authority within the ISI is composed of all individual members of the ISI.