The development of the seismic source model is a fundamental component in the modelling of seismic hazard on both a site-specific and regional scale. The characterisation of different source typologies (e.g. fault sources, area sources or grid sources) requires careful consideration of information from different fields of research, including geology, statistical seismology and geodesy. This presents many challenges in reconciling this information and a subsequent understanding and treatment of the respective uncertainties. To support both the regional programs and wider hazard modelling community, the GEM Model Facility is developing the Hazard Modeller’s Toolkit: a suite of tools for the preparation and development of seismogenic source models for earthquake hazard analysis. Functionalities include: i) algorithms for preparation of earthquake catalogues, ii) pre-processing of the earthquake recurrence model (e.g. declustering, statistical estimation of completeness), iii) earthquake recurrence for area sources and iv) earthquake recurrence from geological and/or geodetic slip data.