A SIM lock is a restriction that makes your phone only usable for a specific network provider.
It is the subsidization of the cost of the handset by the operator, as the network limitation is something that you have to put up for in buying the phone at a lower than market price.
The operator imposed this restriction in order to firstly attract you as a customer and secondly lock you into a term contract once you have joined.
Many people wish to leave their network and joining a new one because of cost, handset range or poor customer service, so many people ask “Is it possible for me to unlock my phone then?”
The answer is yes, you can switch your operator, but you will need an unlock code to do it.
Disconnect from the original Network provider
The very first thing that the unlock code would do for your phone is to terminate its connection from wherever you are subscribed to.
It might still show up as having that specific Network Provider, but it is actually no longer connected and has “dropped” from the system.
Enable Your Phone to Connect to Any Network Provider
Once you have already successfully unlocked your cell phone, your phone is now free to connect to any new network provider of your choice.
Of course, you would need the SIM card of the new provider if you want to use their services.
Permit the Use of Two SIM Cards
With an unlocked cell phone, you can also use another SIM card from any network provider.
Of course, if the phone only has one SIM card slot, then you can only use them one at a time.
For phones that have two SIM slots, you are totally free to use either SIM card simultaneously.
This is very handy if you travel and wish to roam on “foreign” networks.
Configure the Phone to a Roaming Setup
After the unlock code has “freed” your phone from the network provider, you can now setup roaming on the handset.
Instead of worrying over an unusable phone when you go overseas, you can now configure it for international use on any network.
The unlock code is usually used by following the proper unlock procedure that is specific to the phone (usually started by simply going into the menu area of your network provider), and entering the code when given a prompt.
Depending on how the phone is actually unlocked, you may still see remnant data from the previous network provider on your phone.
Each and every phone has a unique unlock code that can be determined by your current country, the phone’s current network provider and its International Mobile Equipment Identity (IMEI) number.
One cannot normally determine the exact code on their own, and the unlocking company is usually the one to send the unlock code for you.
While the action of unlocking a phone may look like something out of the law, it is actually legal.
There is no official criminal offense that can be attributed to it, and in fact some network providers themselves offer unlocking services (although a minimum service time requirement might be necessary).