A credit union is a financial co-operative. Its origins can be traced to the co-operative movement and the Rochdale Society of Equitable Pioneers. There are many factors that have contributed towards their development - economic hardship, the co- operative movement, the influence of credit union pioneers and a credit union legislative framework. Commentators have suggested that a restrictive legislative framework has limited their impact in Great Britain. However, a favourable statutory framework has helped the development of credit unions in the United States and Ireland. The study suggests that, even when the laws are similar in facilitating credit unions, there are other factors which may encourage or impede their development. There are two models of credit union development, the old and new. Research illustrates that the new model assists their growth. Whilst adopting the necessary legal framework, the British Government has adopted the new model. Clearly, then, politics and policies as well as often social factors can crucially influence how effective the legal frameworks can be.