What is unlocking?
Unlocking is the removal of SIM restrictions on the modem, allowing the use of the iPhone on any carrier.
The main reason to unlock your iPhone is if you want to use it with a different service provider (ie. switch from AT&T to T-Mobile).
Here are 2 articles you may want to look at:
1.what is unlocking an iPhone?
2.The difference between jailbreaking and unloc
There are two ways to unlock an iPhone. You can either do a software unlock, which usually requires some kind of hacking, or you can do a factory unlock.
Unlocking the iPhone 4 frees the device from its carrier and allows the user to choose a new network for the phone.
Locked and unlocked phones are available from carrier stores, electronics stores, and websites like eBay.
You can unlock your iPhone 4 using a number of different methods, including free methods.
To find out how to unlock your iPhone 4 yourself for free, take a look at the guide below first, you will need to know what firmware you’re running first as some basebands cannot be unlocked.
Jailbreaking and unlocking your iPhone can also cause issues as well as voiding your warranty.
Unlocking will allow you to use your iPhone 4 / 4s abroad or to get a cheaper deal with a different network at home.
In fact, it can be completed with one of the working unlocking services below in a very short spacer of time and for a reasonable price as well.
Before I go into detail about the best services to use I must warn you about two things first – software unlocking and also hardware unlocking.
How to unlock iPhone 4 ?
Network unlock for an iPhone 4 doesn’t use a code or unlocking sequence. The device is remotely unlocked on Apple servers.
1. Insert a simcard from a different network than the one working in your device.
* the unaccepted simcard cannot ask for a pin code at the start. Please use a simcard that doesn’t ask for a pin, or turn the request for a pin code off.
2. Start the device and turn on Wi-Fi
3. Small update should be downloaded.
iPhone 4 is ready to work in any network.
Second option (if the Wi-Fi option doesn’t work)
1. Connect iPhone 4 to the PC by cable with an unaccepted simcard insterted
2. Start iTunes application on your PC
3. Small update will be downloaded.
iPhone 4 is now network free.