 Any organisation could become an Approved Society, as long as it was registered under the Act, and complied with the Act's obligations, including to operate on a not-for-profit basis.As well as societies created by the Trade Unions, and friendly societies, commercial insurers also established Approved Societies, such as the National Amalgamated Approved Society (created by Pearl Assurance and others); the largest Approved Societies were the four operated by Prudential, which collectively looked after 4.3 million members.Many Approved Societies were nominally profitable, contributing more to the National Insurance Fund than they took out.