Just wanted to try the coverage in my area for Tmobile with my Verizon iPhone 5S by just sticking in a temporary sim card and number. Will that work without doing anything with Verizon?
If the phone is unlocked it will work as soon as you pop the sim card in. I am not really sure how you will get a "dummy" sim that has cell service without starting a line with tmobile
A member borrowed a sim card from an AT&T or T-Mobile store to test the coverage. I think you can probably do the same, unless you already have an active one from a friend, etc.