How do I remove the network lock restriction from my iPhone?
If you have purchased an iPhone 3G, iPhone 3GS or iPhone 4 from Telstra and would like to remove the network lock restriction, you need to contact Telstra Business on 13 2000.
When you call us, make sure you have the following details:
Your mobile number
Your iPhone serial number
Your iPhone IMEI number
You can locate these on your phone by pressing the Settings application, select General then press the About option.
To complete the unlock process make sure you have the latest iTunes software on your computer. Once the unlocking has been processed, the next time you tether your iPhone to your computer, iTunes will unlock the phone.