Compilation of data into secure and readily searchable databases ensures ease of use and is fundamental to the success of the programme. The [http://www.bodc.ac.uk/geotraces/ GEOTRACES Data Assembly Centre] (GDAC) is responsible for the compilation, quality control and secure archiving of data received from national data centers and from core international GEOTRACES cruises. It has as its main aims the integration of core GEOTRACES data into global data sets, and making this data accessible to participating scientist and the larger science community according to the GEOTRACES data policy. The GDAC is hosted at the British Oceanographic Data Centre and a dedicated committee with international representation oversees it.