Verizon company really offers a possibility of unlocking your iPhone 4S using SIM unlock. That will allow user to use local SIM cards while traveling. However they don't comment on whether this will be working for T-Mobile and AT&T. That method has nothing in common with jailbreaking unlock method. The Verizon iPhone 4S SIM unlock works permanently and will not affect your phone's warranty.

Verizon iPhone 4S SIM Unlock

Here's a tutorial how to unlock your iPhone from Verizon's contract:

Step One: To get the unlock you need meet such requirements:
  • You must be a Verizon Wireless customer
  • The iPhone 4S you want to unlock must be active on Verizon Wireless service line
  • You must be on Verizon's contract at least for 60 days
  • The service line has to be in good condition for the last 60 days.
  • Verizon allows to unlock only one SIM per 10 months
If you don't meet all of the requirements, named above, you still can contact the company and get your iPhone 4S unlocked. Step Two: After that, put a foreign SIM card into your iPhone's SIM tray. That's required for successful confirmation of unlocking process. Step Three: Dial 1-800-711-8300 (that's Verizon's Global Support number). Ask Verizon's representative for a SIM unlock. If the support doesn't exactly understand what you're up to make sure that they aren't redirecting you to a different department. You have called the right number. Just explain them that there should be a tutorial on how to do that, that the operation allows to use the phone together with local SIM cards, non-Verizon ones, while travelling anywhere around the world. Verizon iPhone 4S SIM Unlock 1 Step Four: You should receive confirmation from the support that the unlock is applied to your account. Check your device, it should recognize your SIM card correctly and connects to the network. The phone will show AT&T roaming if you are inside US. You will see this message:
"Unlock Complete. Congratulations, your iPhone has been unlocked. To set up and sync this iPhone, click Continue."
Unlock message confirmation from iTunes won't appear as it works for factory unlocked phones only. Congratulations, enjoy your iPhone 4S with SIM unlock!