Is my mobile phone locked?
You'll know if your phone is locked to a network if it doesn't accept SIM cards from other mobile companies.
You'll get a variety of error messages when you insert a SIM from another network into your phone such as "incompatible SIM", "enter network unlock code" or "enter subsidy PIN".
If you see one of these messages when you put your 48 SIM into your phone then your phone is locked.
It's really important that before switching your number to 48 to find out if your handset is locked or not. If you have an active 48 SIM pop it in your phone and check if the 48 network symbol appears. If not, or if you get one of the messages above, your phone is still locked.
If you don't have an active 48 SIM contact the mobile operator and they should be able to tell you if the handset is still locked.