  The production in association with a top quark is the most promising search
channel for charged Higgs bosons at the LHC. We review its theoretical
description including next-to-leading order corrections and the combination
with a parton shower. The latter allows us to for the first time answer
questions about the kinematics of all jets in the process. We then describe the
consistent subtraction of intermediate states and present new results about the
bottom mass uncertainty impacting the parton densisities.
