Chosen Solution
my iphone 4 have aproblem with sim when i try to put sim on my phone on the same activation time it says sim not vaild try another carer sim i tyr many sim do you have asolution
Assuming you just got it, and have never used it before with your own SIM, I believe your iPhone to be carrier locked. You can use the IMEI number to try and find the carrier it is locked to, if it is possible to unlock, and the cost and time it takes. For an iPhone 4, the IMEI can be found A/ on the tray of the SIM card, or B/ in Settings>General>About, or C/ by dialing *#06# or D/ by pressing on the “i” that appears before the activation screen when you first start an unactivated iPhone. Services of this kind are available online on eBay and from independent websites. Just google something like “factory unlock service for my iPhone 4.”
