My phone has worked for a year and now says INVALID SIM in the corner. Can't make/receive calls, texts, or use data. I've powered off and on. I removed the SIM card and put it back in. I've made sure that Airplane mode is off. Any suggestions?
I'd go by a corporate store and get a free SIM replacement.
try a soft reset (hold down power + home button until the Apple appears - no data loss), if that doesn't work try a software update. if that doesn't work try to get the SIM replaced (free at any corporate Verizon store). last resort - check if you have the manufacturer's warranty/insurance for replacement