The study analyses the vicious circle, which generates a typical market failure, between supply and demand of financing to the Social Economy Organisations (SEO). These organisations hardly find financing in the market adjusted to their needs and due to their organisational bottlenecks banks usually don't segment the financing market adressed to SEO. The stydy analyses the financing needs and types, as well as the constraints determined by the predominant business models in these organisations (demand analysis). The financing conditions offered by the banks and other financial institutions are also analysed, identifying the main reasons why the financing market is not segmented (supply analysis). The problem is analysed not only from the perspective of the more traditional SEO, but also from the point of view of the new trend of social entrepreneurship ventures, concluding that he financing models and types should be completely different, requiring debt instruments for the former and equity and quasi-equity instruments for the latter. The study also concludes that the evolution of public policies supporting SEO will also be crucial to consolidate the Access of SEO to financial instruments, either by supporting the management and organisational capacibilities or creating incentives to the banks in order to adapt their products to SEO needs.