Multiple classification systems for ecosystem services (ES) make comparison and integration between studies and assessments very difficult. With the fast-growing number of ecosystem services assessment and valuation studies, there is a need to identify general agreed definitions and to design a ‘common base’ that enables comparisons between ecosystem services assessments at different places. The recently developed ‘Common International Classification for Ecosystem Services’ (CICES) is aiming to fill this gap. One of the advantages of the CICES approach is that it allows adjustment to local conditions. Via an iterative consultation round with Belgian experts - from administrations, policy support units and research centres - CICES has been adapted to the needs of a highly populated country where multi-functional land use is very common. The goal of CICES-Be is to introduce a common reference base for ecosystem services in Belgium, which is locally adapted and compatible with an international standard.