There are two types of phones available in the market where one is sold by the manufacturer directly as unlocked phones and the other is sold through the network carrier that lock the SIM to their network services. When you buy a locked phone you should remember that you cannot change the SIM as other network carriers don’t work on the phone unless the phone is unlocked. To have the phone unlocked you can either contact the network services or a third party unlocking services who gets the job done for you. While the network carrier unlocks only if you meet their unlock terms and conditions, the third party does the job irrespective of your phone or network service carrier charging a fee and offering you the freedom to enjoy unlocked phone services.

 

 
You can unlock Vodafone iPhone by contacting the third party unlock services who can do this by two methods. One method is you have to send the IMEI no of the phone and they shall send you back the unlock code for your phone with the user instructions. You can also unlock the Vodafone iPhone through installing the latest version of iTunes. You can also unlock ZTE phone by following a few simple steps. You have to send the IMEI number of the phone which you can find by dialing *#06# and also send across the phone model number and mobile operator code. Within 24 hours you shall receive the unlock code from the third party unlocking services. You should then insert a not allowed SIM card and switch on the phone. It asks for the unlock code and you can enter the code sent to you and have the phone unlocked.
 

 
Similarly, you can also unlock Virgin phone of any model by sending the IMEI number and receiving the code by paying a few dollars. The code cost depends on the network carrier services and the phone model. To unlock Virgin iPhone the same process applies else you can install the latest version of iTunes through internet connectivity and connect the phone to iTunes with a non accepted SIM. You then wait till the iTunes detects the phone and then you have to disconnect the phone and connect it after 10 seconds to have the phone unlocked permanently. To unlock Verizon iPhone also the same process applies.  
 
You can enjoy many benefits by having the SIM unlocked. You can switch to local carriers when traveling abroad to avoid heavy roaming charges. You can also switch to GSM carrier of your choice offering cheaper rates and best services. The resale value of the unlocked phone increases tremendously. The best part is that you don’t need any technical knowledge or skills to unlock the phone other than following the instructions sent by the third party unlocking services.