Charged Higgs-boson pair production at hadron colliders yields information about the trilinear couplings involving charged Higgs fields in extensions of the Standard Model (SM). We consider the two-Higgs doublet model (2HDM) extension and obtain next-to-leading order QCD predictions for the charged-Higgs pair production ($H^+H^-$ production). All production modes, i.e. Drell--Yan-like production, gluon fusion and vector-boson fusion are included in the analysis. We determine uncertainties originating from the scale dependence, the parton-density functions and strong coupling $α_s$ at the LHC. We observe that the QCD corrections lead to a significant reduction of the relative scale dependences. These improved predictions will allow for a quantitative interpretation of experimental measurements, in case that charged Higgs states will be observed.
