How to enter the SP (Service Provider) unlock code for Pam Treo phones:
Palm Treo 600, 650, 680
1. Insert a SIM card from another network into the phone.
2. Wait until the phone boots (starts) completely and turn on the handset by pressing the Red button for 2 seconds. It will show "SIM card not allowed" or a similar message.
3. Input *#*#CODE# and press the Green dial button. CODE is the 8 digit unlock code you received. When you see "SIM lock has been removed from this handset". Your phone is unlocked.
Palm Treo 750
Insert a SIM card from another network and when prompted for unlock code, enter the code you recevied.