🔑 How to Choose a Strong, Secret User Code for Lock My Devices

A strong user code is long, unique and known only to you and the people you trust. Use a short passphrase of three or four unrelated words (or 12+ mixed characters), avoid birthdays, phone numbers and names, and never share it publicly.

In Lock My Devices there are no accounts or passwords. The user code you choose is the only thing that links your devices together, so it deserves a minute of thought.

Why the code matters

Every device saved with the same user code forms a group. Anyone who enters that code — in the app or on the website’s lock page — can lock every device in the group at once.

What someone can’t do with your code:

• Unlock your devices or bypass your PIN.
• Read your data, see your location or erase anything.

What they can do:

• Lock all your devices, repeatedly, which is a nuisance at best. A guessable code also makes it easier for strangers to land in your group by accident.

So the code isn’t a door key to your data, but it is the key to the “lock” button. Choose accordingly. You can read more on the how it works page.

Five rules for a strong user code

1. Make it long. Length beats complexity. Each extra character or word multiplies the number of possible guesses.
2. Make it unique. Don’t reuse your email password, Wi-Fi password or phone PIN.
3. Avoid personal data. Birthdays, phone numbers, licence plates, pet names and house numbers are the first things someone who knows you would try.
4. Avoid patterns. 123456, qwerty, password1 and keyboard walks are guessed instantly.
5. Keep it secret. Share it only with the people who should be able to lock the devices, such as a partner.

The passphrase approach

The easiest way to get a code that’s long and memorable is a passphrase: a few random, unrelated words joined together.

(Don’t copy these examples. Make your own.)

Tips for a good passphrase:

• Pick words truly at random, e.g. open a book on a random page. Song lyrics and famous quotes are predictable.
• Add a separator like a hyphen or a digit between words if you like.
• Make it easy to type on a phone keyboard, since you may need to enter it in a hurry on someone else’s device.

Where to keep it

You may need the code at a stressful moment, for example on a borrowed laptop after your phone has been stolen. Make sure you can recall it without your phone:

• Memorise it, and
• Store it in a password manager you can reach from any browser, or write it on a card kept somewhere safe at home.

Avoid notes apps on the phone itself: if the phone is gone, so is the note.

Sharing with family

If several family members should be able to lock all devices, share the code in person or through a secure channel. Don’t post it in a group chat that others can see, and don’t write it on the device or its case.

If you want children’s devices to be lockable separately from yours, use two different codes. See the scheduled lock guide for kids for ideas.

How to change your user code

Change it if you suspect someone else knows it, if you typed it on a shared computer, or if someone leaves the household.

1. Open Lock My Devices on the first device and verify yourself.
2. Go to the User Code screen.
3. Enter the new code and tap Continue.
4. Check that the main screen shows UserCode: … with the new code.
5. Repeat on every device in your group.

Devices still on the old code form their own group until you update them, so don’t skip any.

Safety on the website

The lock page doesn’t store your code, uses HTTPS, and limits how many requests can be made, which slows down guessing. A long code makes guessing practically hopeless.

Ready to set up? Follow the remote lock guide, or see the FAQ for more answers.