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Imagine leaving your front door wide open every time you left the house. Your valuables, your documents, your personal belongings — all accessible to anyone who walked past. You wouldn’t do it. Yet millions of people do the equivalent every day with their phones and computers — leaving them completely unlocked and unprotected.

Locking your device takes about two minutes to set up. After that it becomes automatic — something you never think about, like locking your car. This article shows you exactly how to do it and why it matters more than most people realise.

Why locking your device matters

Your phone is no longer just a phone. It contains your banking app, your WhatsApp conversations, your photos, your emails, your contacts, and in many cases your saved passwords. If someone picks up your unlocked phone — whether it’s stolen, left on a table, or borrowed by the wrong person — they have immediate access to all of it.

In South Africa specifically, phone theft is a real and common risk. But the threat isn’t only from strangers. An unlocked phone left unattended at home, at work, or at a social gathering can be accessed by anyone nearby. Most people who experience financial fraud via their phone didn’t have their phone stolen — someone simply picked it up while it was unlocked and had a few minutes alone with it.

A lock screen is the single most effective barrier between your private information and everyone else.

Locking your phone

The four types of phone lock

Modern smartphones offer four ways to lock your screen. Here they are, from most secure to least:

1. Fingerprint — You press your finger against a small sensor on the phone — usually on the side button or the back of the phone, or built into the screen itself. The phone reads your unique fingerprint and unlocks instantly. This is the most secure and the most convenient option because no two fingerprints are alike. If your phone has this feature, use it.

2. Face recognition — Your phone’s front camera recognises your face and unlocks automatically when you look at it. Convenient and secure on most modern phones. Less reliable in poor lighting or if you’re wearing a hat or sunglasses.

3. PIN — A 4 to 6 digit number you enter each time. Simple, reliable, and works in all conditions. Choose a PIN that has no obvious connection to you — not your birth year, not 1234, not your ID number. A random combination you’ve written in a safe place is ideal.

4. Pattern — You draw a shape by connecting dots on a grid. Easier to remember than a PIN but generally considered less secure — patterns can be guessed from smudge marks on the screen, and many people use obvious shapes like the letter Z or L.

The fingerprint + PIN combination is the recommended setup — fingerprint for everyday convenience, PIN as the backup when the fingerprint doesn’t read correctly.

Setting up a lock screen on Android (Samsung and others)

1. Open Settings — the gear icon on your home screen or in your notification bar
2. Scroll down and tap Lock screen or Security and privacy (the wording varies slightly by phone model)
3. Tap Screen lock type
4. Choose your preferred lock type — Fingerprint is recommended
5. Follow the on-screen instructions to register your fingerprint — you’ll be asked to press your finger against the sensor repeatedly until the phone has a complete reading
6. Set a backup PIN when prompted — you’ll need this if the fingerprint doesn’t work
7. Tap Done

Your phone will now lock automatically when the screen goes dark.

Setting up a lock screen on iPhone

1. Open Settings
2. Scroll down and tap Face ID & Passcode (newer iPhones) or Touch ID & Passcode (older iPhones with a home button)
3. Tap Set Up Face ID or Set Up Touch ID and follow the instructions
4. Set a 6-digit passcode as your backup when prompted
5. Tap Done

Setting your auto-lock time

Once your lock is set up, tell your phone how quickly to lock itself when you’re not using it.

On Android: Settings → Lock screen → Screen timeout → choose 30 seconds or 1 minute

On iPhone: Settings → Display & Brightness → Auto-Lock → choose 1 minute

One minute is the recommended setting. Long enough that the screen doesn’t lock mid-conversation, short enough that a stolen or unattended phone locks itself quickly.

Locking your computer

Windows computers

Windows offers several ways to lock your computer. The simplest and most important is the login password or PIN — the screen you see when you first switch on or wake the computer from sleep.

Setting up a PIN on Windows 10 or 11:

1. Click the Start button (Windows logo, bottom left)
2. Click the Settings gear icon
3. Click Accounts
4. Click Sign-in options
5. Under PIN (Windows Hello), click Set up or Add
6. Enter your Microsoft account password when prompted
7. Choose a PIN of at least 6 digits — not your birth year or 1234
8. Click OK

From now on, whenever your computer wakes from sleep or starts up, it will ask for this PIN before allowing access.

Locking your computer quickly: If you’re stepping away from your computer — even for a few minutes — press Windows key + L on your keyboard simultaneously. This locks the screen instantly without shutting down. Press it every time you walk away. It becomes a habit within a week.

Setting your computer to lock automatically

You can also set your computer to lock itself after a period of inactivity — useful if you sometimes forget.

On Windows:

1. Right-click on the desktop (an empty area of your screen)
2. Click Personalise
3. Click Lock screen
4. Click Screen saver settings
5. Set a time — 5 minutes is recommended
6. Tick the box that says On resume, display logon screen
7. Click OK

Now if you walk away and forget to lock, the computer will lock itself after 5 minutes.

Protecting your phone if it’s lost or stolen

Setting a lock screen is the first layer of protection. The second is making sure you can find, lock or erase your phone remotely if it’s ever lost or stolen. Both Android and iPhone have this built in — but you need to set it up before something goes wrong, not after.

Android — Google’s Find My Device

1. Open Settings
2. Tap Google
3. Tap Find My Device
4. Make sure the toggle is switched On

That’s it. If your phone is ever lost or stolen, go to findmydevice.google.com on any other device, sign in with your Google account, and you’ll be able to see your phone’s location on a map, make it ring loudly even if it’s on silent, lock it remotely with a new PIN, or erase everything on it completely.

iPhone — Find My

1. Open Settings
2. Tap your name at the top
3. Tap Find My
4. Tap Find My iPhone
5. Switch it On

To locate your phone, go to icloud.com/find from any browser, sign in with your Apple ID, and the same options are available — locate, lock or erase.

Never lend your phone unlocked

This deserves its own section because it’s something most people don’t think about.

Even among people you trust completely — family members, close friends, colleagues — lending your phone while it’s unlocked gives them access to everything on it. In most cases nothing will happen. But the risk isn’t worth it for a simple reason: you don’t know what someone will do with a moment of unsupervised access to your banking app, your WhatsApp, or your personal photos.

The right approach is simple — if someone needs to make a call on your phone, unlock it yourself, open the phone dialler, and hand it to them open on that screen. Don’t hand over an unlocked home screen.

Be aware of your screen in public

Shoulder surfing is when someone watches your screen from behind or beside you while you type your PIN, enter a password, or do online banking. It happens in queues, on taxis, in shopping centres and at ATMs.

A few simple habits make a big difference:

• Cup your hand around the phone screen when entering a PIN in public
• Be aware of who is standing close behind you at an ATM or when paying by phone
• If someone is standing uncomfortably close while you’re using your phone, move or wait until they’ve gone before entering any sensitive information
• Use a privacy screen protector — a thin film available from most phone accessory shops for around R80 to R150 that makes your screen visible only from directly in front, not from the side

Try this now

Check right now whether your phone has a lock screen active. Pick it up, press the power button to wake the screen, and see whether it asks for a PIN, fingerprint or face before showing your home screen. If it goes straight to your home screen without asking anything — your phone is unlocked and unprotected. Go to Settings and follow the steps above to fix that today. It takes two minutes and is one of the most important things you can do.

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