The organisation is the national coordinating body for Social Service Agencies (SSAs) in Singapore. SSAs are non-profit organisations that provides welfare or social service to vulnerable or disadvantaged groups in Singapore, and in 2018 were renamed from the term Voluntary Welfare Organisations (VWOs).
SSAs are members of NCSS. A SSA is therefore not a legal structure (they can be registered as societies or companies limited by guarantee), but a classificatory category used to describe a subset of voluntary organisations in the business of providing direct welfare services.
The Social Service Institute and the Community Chest are part of the National Council of Social Service.