Samsung Galaxy Tab S4

Slide your finger downwards starting from the top of the screen.

Press the settings icon.

Press Biometrics and security.

Press Other security settings.

Press Set up SIM card lock.

Press the indicator next to "Lock SIM card" to turn the function on or off.

Key in your PIN and press OK.

If the wrong PIN is entered three times in a row, your SIM is blocked. To unblock your SIM, you'll need to key in your PUK. The PUK can be obtained by contacting Customer Service. Please note: If an incorrect PUK is entered ten times in a row, your SIM is blocked permanently. In this case, you need a new SIM from Telstra.

Press the Home key to return to the home screen.