This paper examines the successes, challenges and modalities of the provision of financial services by trade unions. It is structured in two parts. The first examines the existing literature on the financial service experiences of unions through various institutional arrangements. The second part is a broad view of union-led financial service provision based on a survey of 166 unions representing 441.6 million workers worldwide, along with eight case studies that serve to illustrate the contextual factors influencing financial service provision by trade unions. The findings demonstrate that trade unions offer a range of financial services including loans, savings, insurance and retirement schemes through diverse modes of implementation. Mutuals and cooperative structures are popular models for union-led financial service provision. Others have sought for more knowledge and capital-intensive institutional models, such as setting up brokerage agencies or establishing banks.