How do I get my SIM Card from International iPhone to work in USA iPhone?
I lived in Switzerland for 5 years and purchased an (unlocked) iPhone 6 from a local Mobile Service Provider and set up my account. I used this as my main work phone and for e work mails, etc. I had also been issued a work iPhone (iPhone 5) with a USA number while living abroad that had some security encryptions on it since it came straight from my Company. So I had 2 iPhones, one was an iPhone 6 unlocked with a Swiss Number and one was a more secure iPhone 5 with a USA number. I recently moved back to the USA and still have both phones. I preferred the iPhone 6, so before I moved, I switched SIM cards while in Switzerland and the iPhone 6 worked perfectly with the USA SIM in it. Cell signals, Phone calls, Wifi, etc all worked. Once my Swiss contract ran out, I was just going to switch the SIM Cards and use my iPhone 6 with the USA SIM in it as my only iPhone. Now I am back in the USA and when I switched the SIM cards, the USA SIM does not pick up any mobile signals at all in the iPhone 6, but still works normally in the iPhone 5.
Does anyone have any suggestions?
Thanks very much in advance