  We discuss the calculation of charged Higgs boson production in association
with top quark in the MC@NLO framework for combining NLO matrix elements with a
parton shower. The process is defined in a model independent manner for wide
applicability, and can be used if the charged Higgs boson mass is either
greater or less than the mass of the top quark. For the latter mass region,
care is needed in defining the charged Higgs production mode due to
interference with top pair production. We give a suitable definition applicable
in an NLO (plus parton shower) context, and present example results for the
LHC.
