Since 2009, Open Government Data initiatives have been launched worldwide and the concept of open data is gaining momentum. Open data are often associated with realizing ambitions, such as a more transparent and efficient government, solving societal problems and increased economic value. However, between proposing an open data policy and successful implementation are some practicable obstacles, especially for government agencies required to generate sufficient revenue to cover their operating costs, so-called self-funding agencies. With lost revenue due to open data, there is a real risk that the update frequency and the quality of data may suffer or that the open data policy may even have to be reversed. This article has researched the financial effects of open data policies for self-funding agencies on their business model. The article provides some hands-on proposals for self-funding agencies having to implement an open data policy whilst ensuring their long-term sustainability.