The InterProScan software is distributed under the open source Apache License, as are the included scanning tools (except SignalP and TMHMM). Therefore, you do not need a special license for commercial use but please cite the resource and keep the Copyright statement with your installation.
Jones P, Binns D, Chang HY, et al. InterProScan 5: genome-scale protein function classification. Bioinformatics. 2014;30(9):1236-1240.