To enable SIM card lock on your phone device is important to protect your SIM data and your valuable information. Many people do use password to lock their phone screen and forget to use SIM lock to protect data of their device.
If don’t enable SIM lock, you should do because if you’re unlucky enough to lost your phone or stolen, it is not only the hardware that fall into the wrong hands, all your valuable data, information and contacts contain in the SIM are not also save in a wrong hands.
If you enabling a SIM card PIN lock on mobile device, whenever your Android or iPhone is power off and subsequently switched back on again, your enable SIM lock PIN will be required you to entered a CODE before can be used or access your contact, messages and every information on your phone.
So, if anyone removes your SIM card from your phone tries to use it in a different way even after your phone is lost or stolen, it will be useless without the person being know your personal Identification Number (PIN)
How to enabling SIM Card lock
1. From your home screen, open the Settings app.==> Go to Mobile Data, and scroll down to SIM PIN.
2. Tap on SIM PIN, you will see a toggle to turn it on or off, and an option to change the PIN will be in (grey colour).
NOTE: You need to know the PIN code you’re using very well as not to forget it whenever you want to unlock it when you powered on and off your phone.
MOST IMPORTANTLY: If this is your first time to use SIM Card lock on, you will be asked to enter your operator’s default SIM Card PIN which is 8 digit numbers from your Mobile Operator Service Provider, usually come with your purchased Mobile SIM Card packed.
3. Enter your Default SIM Card PIN correctly and you’ll see a toggle set to enable, then Change PIN Option.
You only have three attempts to enter the PIN before the SIM card is locked, and you won't be able to make any phone calls or send texts. Except you can call your Mobile Service Provider to give your SIM card default PIN or use your Personal Unlocking Key (PUK). When you enter your correct PIN, you will see the toggle is set to enabled, and you can now use the “Change PIN” option.
If you get it done feel free to leave your comment, and if you need any assistant you can let me know.