There are, as of 2025, 174 members of the International Organization for Standardization. Three types of membership status can be distinguished:
- Full member (member body): sets the course for ISO standards development and strategy: participates and votes in ISO technical and policy meetings; sells and adopts ISO standards nationally.
- Correspondent member: attends ISO technical and policy meetings as an observer; sells and adopts ISO standards nationally or within their membership territory.
- Subscriber member: keeps up to date with ISOβs work, but cannot participate in it; does not sell or adopt ISO standards nationally.