When you buy an iPhone from a carrier, it is highly likely that your iPhone comes locked with the carrier's network. Simply put, you are bound by an agreement with your carrier to use your carrier's network till a specified time period. But you may still need to use other networks on your iPhone at different times (for example, when travelling to another country). In such situations, you need to unlock the iPhone. There are different methods available for Apple iPhone Unlock. Not so long ago, you could unlock or jailbreak your phone by installing a software. But you can no longer do that.
Still, you have the following methods available.
Contact your carrier
Your current telecom carrier could unlock your iPhone or migrate to office 365 if you have either completed your contract or you want to pay the contract termination fee, if there is any such clause in the agreement. Even if your contract has not expired, your carrier may at its discretion unlock the phone especially if you are travelling to a place where the carrier's network is not available.
Contact one of your carrier's rivals
Often, when you promise to switch over to one of your carrier's rivals, the rival may unlock the iPhone. But you need to note that even in this situation your iPhone may again be locked. So, you need to talk to the rival carrier and find out their unlocking policy. You can try to convince the rival carrier to unlock your phone for a fee instead.
Ensure that your phone is compatible with the carrier's network
This applies only if you are switching over to a new carrier. You need to ensure that your phone is compatible to the carrier's network. For example, if the carrier employs CDMA, your phone must be CDMA-compatible.
Find a paid unlocking service
A number of companies sell unlock codes online. However, you need to first find out phone unlocking laws in your country. Companies that sell unlock codes usually operate out of countries where unlocking is not deemed illegal. So, if you stay in a country where illegal unlocking is prohibited, you may want to first have a quick consultation with a lawyer, just to avoid problems later. Do research about such phone unlocking companies well before paying them for the unlocking code.
Retrieve your IMEI number
Prior to providing unlock codes for your phone the company needs to have the International Mobile Station Equipment Identity (IMEI) code. You can retrieve the IMEI number in any one of the following ways.
On the phone, dial *06 and the IMEI code will appear on the screen.
On the iPhone 5, the IMEI is engraved on the back.
The IMEI code is printed on the SIM card tray of iPhone 4, 3G and 3GS.
Activate the unlock
You need to activate the unlock feature after you have applied the unlock code. Usually, the unlock activity is successful when you insert the SIM card and the network becomes available. If the network is still not available, then you need to activate from the Settings option.