The most common form of registered member-owned institution is a cooperative. Although cooperatives vary in type and membership size, all are formed to meet the specific objectives of members and are structured to adapt to members' changing needs. Thus cooperatives are formed by individuals who coordinate among themselves (horizontal coordination) to achieve vertical integration in their business activities. Specialised financial service cooperatives are most widely known as credit unions or savings and credit cooperatives. However, financial services may also be provided by multi-purpose cooperatives or marketing cooperatives.

Newer forms of member-owned institutions such as Financial Service Associations and Village Banks will also be addressed in this topic.