Unlocking 101

First, you should understand why phones are locked in the first place. Networks/providers/carriers lock phones so that that you are forced to use their network at their rates. No other SIM card will work in their phones. You cannot take advantage of better rates from other providers. A locked phone is subject to roaming charges and you have no choice.

When you unlock your phone, you are free of these restrictions. There is no more restriction placed on the phone by a network carrier.

After a phone is unlocked, you are free to use any network and any SIM card of your choosing. You can insert and use SIM cards purchased while abroad that allow you to take advantage of better rates for calls and SMS messaging.

Basic advantages are that you no longer pay roaming charges, and you can switch back and forth between carriers/networks. Other advantages are the increased resale value of your phone, locking is a guaranteed safe procedure for your phone and cannot harm it.

A SIM stands for a 'subscriber information module'. It is a chip which inserts into a GSM handset and is what allows the phone to work within a given network. Non-GSM phones, on the other hand, are based on an ESN basis, which mean it has a unique serial number that the provider supplies to it. It identifies who you are, knows to send calls to you when your number is dialed and also controls your calling rates according to your contact or pay-as-you go plan that you signed up for with the carrier.

That's a simple one. Just borrow a SIM card from a friend that comes from a alternate carrier from yours. If the phone works, your phone is unlocked. If you get an error message, it means you've got a locked phone.

No. Once unlocked, your phone stays unlocked unless you reprogram it to become locked again.

Yes. While you will still be paying your provider the usual monthly rate, you can save money by using other SIM cards for other regions or countries if you are traveling. You can avoid roaming charges and you can search around for better rates wherever you are.

None at all for code unlocking. In the case of cable unlocking, being familiar and comfortable with computers and cables is necessary for success using this mode. In the case of code unlocking, the instructions are easy to follow and requires only that you be able to enter the code unlocking number on your keypad. If you can dial a telephone number, you can unlock via code.