Can I use the phone even if I plug the KT USIM into the SKT cell phone?

pu1. SKT and KT have the same communication frequency, so even KT-only phones can use SKT USIM chips

2017-12-21

OK

pu2. KT and SKT can use SK Telecom's USIM on KT's mobile phone because the USIM is compatible with each other

2017-12-21

OK