Our licensing mechanism implicates that every PC which is going to be controlled remotely must have a Radmin license. Therefore when you purchase single Radmin license you purchase a lifetime remote control of one PC. Radmin activation is hardware-bound and transfer of a license can only be possible in hardware replacement cases. For short-time remote control sessions you can use Radmin trial version.
Or you can include license price to your package and purchase Radmin license to the client's name. In this case you can leave Radmin on client's PC.