We determine approximate higher-order QCD corrections to semi-inclusive DIS. They are derived using the threshold resummation formalism, which we advance to high perturbative order. Our numerical estimates suggest a very good perturbative stability of the semi-inclusive DIS process. We also explore the impact of the higher-order corrections on the determination of pion fragmentation functions in a global QCD analysis of e+e- annihilation and semi-inclusive DIS data.