Newer Sony Models (Xperia Range)
Most new Sony will ask for the unlock code when you put a sim in it wont yet accept because it is locked.
when you receive your unlock codes they will look similar to the EXAMPLE below
Your unlock code is :
These letters CCK,NCK,NSCK,SPCK are telling you which code to use for certain locks on your handset.
So you need to find out which lock is active on the handset.
To do this you need to look in a secret menu on the phone
Tap the following in as if you were dialling a number to make phone a call...
A new hidden menu will appear.
Tap on service info
Tap on SIM lock
If you have [x] Network 5 - this means your phone needs the net NCK Code
If you have [x] Service providor 5 - this means your phone needs the SPCK Code
Other Models: 99% SonyEricsson
1 - Switch ON your phone without SIM Card,
2 - Press 1 time the left arrow,
3 - Press 2 times the button * ,
4 - Press 1 time the left arrow,
5 - The message "Personalize with MNC2" will appear,
6 - You can now enter the Unlock Code we send to you.
If your phone have a "JOGDIAL" (ex : SonyEricsson K700i) you must press "down arrow" instead of "left arrow" for step 2 & 3. We mean by "Down Arrow" to direct the Jogdial down !
W950 models need to use * up * down ** down (up/down using the jog dial on the side).
tap repeatedly the star key to get p w + symbols