Samsung Galaxy A55
It's not possible to start my phone
Solution 2 of 7: Your phone is locked to EE
If your phone is locked to EE and you try to use a SIM from another operator, the display will tell that your SIM is invalid.
Call customer services on 150 (from an EE phone), 07953 966 250 (from other phones) or visit My EE to have your phone unlocked.