The techniques used for unlocking phones are different depending on the phone model or carrier. Here are the most commonly used techniques: phones can be unlocked with help from a specialized company, by means of special equipment and with help from your current operator.
As far as the first technique is concerned, most people choose it because it is easier, quicker and cheaper. These specialized companies will need your IMEI number, based on which they will be able to generate the unlock code. However, you must very careful as there are many fraudulent companies as well.
In other cases, phones can be unlocked by companies able to provide you with special equipment, which can vary depending on the type of phone. This is a less common technique and it is not as safe or cheap as the first one.
If you trust your operator, you can call him to ask for help for your phone unlocking. You may be required to give a two weeks’ notice. You may also be asked to pay an unlocking fee, but this depends on the terms and conditions stipulated in your agreement. For instance, you may be obliged to have used that network for 12 months if you were on a post paid plan. Your service provider will unlock your phone by means of a code, just like the specialized companies, but this service may turn out much more expensive.
Depending on your needs, situation or size of your budget, you can choose among these three methods the one which suits you best. Most people choose the specialized companies to unlock their phones, because it is the most convenient variant in terms of quickness, easiness and affordable prices.