If your SIM card came with a default SIM PIN code, you can change it to something more secure. Not all network service providers support this.
Select your SIM PIN
You can choose which digits to use for the SIM PIN. The SIM PIN code can be 4-8 digits.
Tap Settings > Security > SIM card lock.
Under the selected SIM card, tap Change SIM PIN.
Savjet: Ako ne želite zaštititi SIM karticu PIN kodom u Postavljanje zaključavanja za SIM karticu, prebacite Zaključaj SIM karticu na Isključeno, i upišite svoj trenutačni PIN.