Domestic SIM Unlock (DSU)
A domestic SIM unlock allows a device owner to insert another domestic carrier's SIM card into the device in order to attempt to activate the device on that carrier's network.
Once you are told that you are unlocked. Go to your dial pad and dial "##873283#" Make the call and it will update your service and unlock your phone. No need to reset or restore your phone.
Also if you have a iPhone you don't have to call to get it unlocked, just do the above and you will be domestically unlocked. All iPhones from are automatically unlocked from a few days ago. You just have to perform the above.