I've done it on Verizon for several years and have had to pay their activation fee every time. Last year was an exception because the phones sent direct from China would not activate and I had to return them at an Apple store, cancel those loans on the IUP, get new phones, then activate. I had gone to Verizon store first and they could not activate them, so considering that they waived the activation fee ($35 per line if I recall correctly).