You can add an extra layer of security to your iPhone by using the Passcode Lock feature.

This allows you to enter a 4-digit password that must be entered to gain access to your iPhone and its data. We also show you what to do if you have forgotten your passcode

Click the Home button to bring up the main menu

Click on Settings

In the Settings screen click on General

In the General screen click on Passcode Lock

This will open the Set Passcode screen. Enter a memorable 4-figure code and re-enter it when prompted

You will now be at the Passcode Lock screen. You can change when you are prompted to enter the Passcode. The default setting - Immediately - means you will be asked to enter it as soon as your start using the iPhone. But you can change the setting so that the prompt appears after a certain period of use

Press the Home button to return to the main menu.

Forgotten your iPhone Passcode?

If you have forgotten your iPhone's Passcode you will need to restore your phone via iTunes.

But first you have to put your phone into the restore mode which is a slightly fiddly process.

Plug your iPhone into your PC or Mac with the USB cable

Press and hold the power button at the top and then slide to power off the iPhone

Press the power button to power the iPhone on and keep it held while simultaneously pressing the home button

After a few seconds a yellow alert triangle will appear and the iPhone will say it is iPhone Restore Mode.

Open up iTunes and click on the Summary tab

Click on Restore to restore your iPhone. This will reset all your iPhone's setting to the factory defaults, including the Passcode. You should then follow the steps above to activate the Passcode with a memorable number