How to Unlock a G1 Phone for Free

1. Turn on your T-Mobile G1. Dial *#06# to display your handset’s unique international mobile equipment identity (IMEI) number.
2. Call T-Mobile Support. (See Resources) Ask for your free SIM unlock code for your T-Mobile G1. Give the representative the IMEI number to your G1. Give the representative a valid email address to which to send the SIM unlock code.
3. Turn off your T-Mobile G1 when you receive the SIM unlock code by email. Remove the back panel and battery from the phone. Replace the T-Mobile SIM card with one from another mobile service provider. Replace the battery and battery panel. Turn the G1 back on.
4. Click “OK” when the G1 displays a message that it does not recognize the SIM card installed. Enter the SIM unlock code on the next screen. Click “OK.” Use your T-Mobile G1 as desired after you get the confirmation message that the G1 has an unlocked SIM.