  The public collider phenomenology computing tool CheckMATE (Check Models at
Terascale Energies) was originally designed to allow theorists to quickly test
their favourite BSM models against various existing LHC analyses performed by
ATLAS and CMS. It offers an automatised chain of Monte Carlo event generation,
detector simulation, event analysis and statistical evaluation so that it can
automatically determine whether a given parameter point of a BSM model is
excluded or not. Currently, it contains more than 50 individual ATLAS or CMS
analyses whose several hundred signal regions target various final states as
they typically appear in theories beyond the Standard Model. In this study, we
extend this functionality to allow sensitivity studies for the International
Linear Collider. As an example, we implemente a dark matter monophoton search
and use it to analyse three benchmark scenarios with different assumptions
about the interaction between dark matter and Standard Model particles. We
determine the ILC sensitivity expected for a $\sqrt{s} =$ 500 GeV, $L = 500$
fb$^{-1}$and compare the results for the cases of completely unpolarised beams
and for individual lepton polarisation settings.
