When people buy their iPhone from any service provider with a service plan, they find themselves unable to use it on other networks. This happens due to the GSM locked service of the iPhone. You must do GSM unlock to use it over the network of your choice.
But most do not know what is the difference between a factory unlocked and GSM unlocked iPhone.
To understand it assume you bought an iPhone from an Apple Store, then this handset is called factory unlocked. You can use it over any network you desire.
On the other hand, when you buy a GSM locked phone it can work with only some selected network carriers. You cannot switch your carrier just by switching sim cards.
To GSM unlock your phone use the steps given below:
1. Your network operator is your savior, they can unlock your iPhone.
2. Request them to unlock your iPhone, if your account is compatible, they will do it. But you may have to wait for some days.
3. When they confirm unlock from their side, it is your turn to jump into the battlegrounds.
If you want to change carrier and have a sim card for the same purpose use the steps given below:
1. Say bye to your old sim and allow your new sim card to intimidate with iPhone.
2. Set-up your iPhone to use it like before.
So, by following these simple steps you can switch your network carriers anytime.
You need to understand that it can happen with any phone or handset as many assume that this condition is restricted only to iPhones.
All iPhones are factory unlocked if you buy them from Apple Stores. Only handsets bought from a network provider are generally GSM unlocked.