How do I set up personal hotspot on my iPhone 4 or 3GS?
If you have an iPhone price plan, you just need to turn on Personal Hotspot from the settings menu of your iPhone.
You can do this by tapping Settings > General > Network > Personal Hotspot and slide the switch to On.
If you do not see this option you may need to update your iPhone's software using iTunes.
If you are on another price plan and try to turn on personal hotspot, you will get a prompt advising you to set it up.
You will need to contact customer services to arrange for the service to be added to your price plan.
Contact your Customer Services team
More about personal hotspot set up