Samsung Galaxy Tab A (10.5) - Turn SIM PIN On / Off
Enabling the Subscriber Identity Module (SIM) Personal Identification Number (PIN) locks the SIM card so it can't be used until the correct code is entered. If the incorrect PIN code is entered too many times, refer to Locating the 4G SIM PIN/PUK - My Verizon Website to obtain a new PIN Unblocking Key (PUK).
From a Home screen, swipe up or down from the center of the display to access the apps screen.
Navigate: Settings > Biometrics and security (Left pane).
From the Security section (in the right pane), tap Other security settings.
From the SIM card lock section, tap Set up SIM card lock.
Tap the Lock SIM card switch to turn on or off .
Enter the current SIM PIN then tap OK.
The default SIM PIN is 1111.