Voluntary Sector Organisation Public Partnerships (IOPs) are a new form of collaboration for voluntary and public organisations, which aim to give financial support ta a welfare service provided by the voluntary actor. The aim of this study is to examine the importance of voluntary organisations in the modern welfare state. The importance they have as welfare producers. In this study i have chosen to look at how Karlstad municipality works with IOP cooperation. My theoretical starting point of this study have been the concept of social capital and how IOP collaboration works from a trust perspective. I have used both document study and interviews to answer my purpose. I have interviewed both officials in Karlstad municipality and representatives of the voluntary organisations that have IOP cooperation with the municipality in Karlstad. The conclusion I have found here is that Karlstad municipality and the three voluntary organisations I met, have a good collaboration with a high level of trust between them. But there is also some dissatisfaction that it is the municipality that benefits most from the cooperation. Another conclusion is that IOP collaboration has a great impact on the individuals who get help through the voluntary organisations. The study shows that many of these individuals would be completely helpeless unless the voluntary organisations improve their work.