Got a new SIM Card for my iPhone 3G and it says SOS Only?

I recently got a Next G Network SIM Card for my iPhone and after I put it in the phone it asks me to unlock the SIM Card which works okay and now it says "SOS Only" where the carrier name should be. This never happened when I used my Optus SIM Card until I got my account and everything moved to Telstra. How can I fix this?

There are 2 things we can try to get it working with the current SIM.

1. Sync with iTunes

2. A manual reset by turning the phone off then on again.

If that doesn't help then the next step I could suggest is popping into to your local store and getting the SIM swapped as it may be faulty.

If it is not unlocked to use other networks Sim cards. You should network unlocked it to use your Telstra Sim card.