by 
To permanently unlock a Sony or Sony Ericsson, the phone must have unlocking attempts remaining.
The limited number of unlocking attempts permitted by the phone manufacturer makes finding out vital before making your unlocking code request through doctorSIM.
Even if the instructions and unlocking code we provide are valid, you will not be able to use them if your phone has run out of unlocking attempts.
Our number one priority at doctorSIM is the total satisfaction of our customers and it is our duty to let them know they need to do this before contacting us for an unlocking code.
Below is how to check the number of unlocking attempts your phone has remaining.
Sony (Sony Xperia U, Sony Xperia P, Sony Xperia Tipo, Sony Xperia Miro) and Sony Ericsson Xperia.
1. Turn on the phone with a SIM card inserted (this is important, because without a SIM card you may be told you have unlocking attempts remaining when in fact you do not).
2. Type the following: *#*#7378423#*#*
3. Select Service Info/Sim Lock. Look on the first line (Network).
4. If there is an X and a number that is not 0, you can unlock your Sony.
5. If instead you see a 0, you will not be able to unlock your phone.
Sony Ericsson Xperia (2011 or before).
1. Press the Home button once.
2. Press the Back button twice.
3. Press the Home button once.
4. Press the Back button once.
5. Press the Home button twice.
6. Press the Back button once.
In summary, the sequence is as follows: 1-2-1-1-2-1.
Once you have accessed the service menu, check the number on the first line next to the word Network.
That is the number of unlocking attempts your phone has remaining.
For more information: Unlock Sony online.
