[eastbayrae]

How do I fix this? The phone worked fine overseas and now here in the states I have bought 3 SIM cards from T-Mobile and all give the error. The phone was bought in the states unlocked and sent to me overseas.

[sinlessearth]

Hate to say it but is sounds like it isnt really unlocked. Mine use to say invalid sim until I got the unlock code from the carrier and now any sim works. If it was bought in the states what carrier is it branded to. Did you buy this from a reputable store?

[roaddash]

Hi, your phone seems to be locked to certain network..so you need to unlock the network..for unlocking , you can use unlock codes..it is very easy..this unlock code is available at many unlock providers . here you need to check for your phone model and the locked network..if it is available you can get the unlock code easily..

[eastbayrae]

The problem was I needed to do a soft reset. Once that was done the AT&T SIM worked.