In the USA, 'mitigation banking' was introduced more than ten years ago. This is a scheme whereby large areas of 'reserve land' are accumulated. Developers can buy a compensation site once a project has been approved. Banking of credits in advance favours acceleration of the approval procedure, because the compensation site is available and of suitable quality. This lowers mitigation and compensation costs and increases the ecological value of compensation, as one large compensation site avoids the fragmentation associated with smaller sites. These arguments, and particularly the fact that land acquisition is already difficult in some regions, make it worth considering the application of mitigation banking in parts of Europe.