1. Turn on the phone without sim card
2. Type *#*#7378423#*#*
3. Select Service info
4. Select SimLock
5. Check where is X
6. If X is on NETWORK, SUBSET or PROVIDER and value is more than 0, you can unlock your phone.
7. If it is 0 unlock by code is NOT possible. The counter is blocked.

› See More: How to know if your Sony device is Hard Locked?