In Australia, the mobile carriers are pretty smart. Why I said so?
Basically, if you're on a contact with carrier A for 12/24 months and you decided to move to other carrier after the contract (stick with the same mobile phone). Definitely, you're able to do so and they are able to port the same number to different carrier for you.
First and foremost, you will need to unlock your mobile phone before you can use it for other carrier. I did that once already and they charged me AUD30-AUD35 to unlock my Nokia 6510 while my husband was being charged of AUD4-AUD45 to unlock his Sony Ericsson.
Right now, I found a way where you could unlock it for free (Undeniable, you will need to bear the consequence!)
This steps is meant to be for Nokia only!!
Step 1: Use the existing carrier SIM and just enter ' *#06# ' - We're looking for the IMEI
Step 2: Write it down and make sure you're getting the correct IMEI
Step 3: Follow the prompt in Unlock Your Device
Step 4: You will get the unlock code (that's really important- and make sure the details matches)
Step 5: Press #
Step 6: Press * three times to get p
Step 7: Press * four times to get w
Step 8: Press * twice to get +
Step 8: Press * twice to get +
It should look like: #pw+ (15 digit unlock code)+1#
E.g.: #pw+123456543456786+1#
It will then restart the mobile phone itself (meaning to say you have successfully unlock the phone)
Anyway, just be mindful that it will locked itself after 3 attempts and I understood that you're no longer able to use the phone!!!
P/S: I managed to unlock 2 Nokia mobile without any trouble! >,<
