I am going to set my senior mom up with an iPhone this holiday. She has an LG flip phone with Consumers Cellular that does texting, and maybe some e-mail. Not sure about the e-mail. She would stay with Consumers for service which would work for her as a minimum sort of data user, probably use very little data beyond e-mail. Is a 4G or LTE SIM card different or would her current SIM work in a iPhone 7? What about form factor? I know she would have to upgrade her account to get data.