"Invalid SIM" on my iPhone 5, how do I fix it?

[Kabob]

Last night I tried making a phone call and it never connected, ever since my phone starting saying "Invalid SIM." I power cycled it several times and then I backed it up and did a factory restore, the issue remains. I also popped the SIM card out, there doesn't seem to be any physical damage or dirt accumulation. Popped it back in and I was getting a normal Sprint signal for about 4 minutes, then the error message reappeared.

Is this something I can fix on my own or do I need to take my phone in? Also, since it's a SIM card do I need to take this to an Apple store or to my cell provider?

Thanks!

 

[TheStu]

I would take it to the Sprint store (see if you can find an official one rather than a kiosk) and see if they can help you.

 

[Kabob]

I would take it to the Sprint store (see if you can find an official one rather than a kiosk) and see if they can help you.

There's one on my way home, I can swing by and inquire.

 

[mobilelover]

Try this guide ==> http://support.apple.com/kb/TS4148 if it does not work then may be Your phone is locked to a carrier and when you put in a SIM from a different carrier you will get the message that you got