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Aron Govil- How you can use the digits of your phone number as a passcode

A phone number with a 7-digit passcode is a familiar sight for anyone who has bought a mobile device explains Aron Govil. But this code is not merely a convenience to make the numbers easier to read on small screens, but also a security measure. A widely known trick allows attackers to discover your PIN by simply calling you and writing down the digits that are played out loud when someone is typing in their passcode at an ATM. This technique only works if the attacker knows which digits have been pressed or is attempting all possible combinations of ten-digit combinations, but it’s still very effective. Using these two pieces of information, they can easily gain access to your account and steal all your money in minutes!

So in order to protect ourselves from these types of attacks, many mobile operators now allow their customers to input the digits of the phone number itself as a passcode. This is often referred to as “PERSONAL CODE”. It’s just like your PIN, but it uses the same security mechanism that protects your call, text and data connections.

You’re Phone Number’s Passcodes

Operators have different policies on how they assign these codes, so if you want to use this protection with your provider it would be best to consult with them first.

In general, here’s how it works:

• The phone number itself is usually the passcode. For example, if your number is 07801234567, then your passcode will be 00007801234567.

• Seven-digit numbers are supported as well, but you should always use a 10-digit code to avoid someone guessing your PIN by calling you and listening to the digits played back to them. For example, if your phone number is 02034546543 then your passcode will be 0102034546543 – making sure no one can guess which digits you pressed!

• Some operators allow users with 5 or 6 digit numbers to input their entire number as the personal code (for example 123456789 would be 1234-56789).

• Some operators allow users to choose their own passcode. For example, if your number is 02086459876 you could use 8645098762 as your personal code – but only if this was enable by your operator beforehand!

• No matter how you store the number, it’s normal for some numbers to show up as “0000” or “1331”. This is just part of the algorithms use to encrypt the data connection and has no effect on security, so don’t worry about it.

How can I find out my personal code?

Some mobile operators also provide a tool that allows you to see what passcode is assign to your phone number says Aron Govil.

Here is how to find out on some of the major mobile providers:

  • EE (UK): Your PIN will be 0000 unless you’ve changed it already.
  • Three UK: You can check your number’s passcode by calling 125 from your Three phone, or on the My3 app for Android and iOS.
  • O2 (UK): Visit, sign in with your username and password, go to Settings > Account & services > SIM security > Personal code. Please note that even if you change this code your new number will still show as “0000” when someone calls you!  The good news is that only people who know your old number will still have access to the original code, but it will still be highly insecure to use your number as a passcode. You should change it immediately!
  • Tesco Mobile (UK): In order to see how many digits are in your current personal security code you can call 4444 from your Tesco Mobile phone or visit and choose your SIM card on the right-hand side of the screen.  Don’t worry: changing your PIN won’t affect this value and you will always be able to enter 10 digits no matter what number is assign to your SIM.
  • Vodafone (UK): Call 321 from any Vodafone phone and press “1” when prompted for an operator selection.  Then press “4” and finally “1” again to see your passcode.
  • Vodafone (Spain): Call 1252 and you will hear a voice telling you the digits of the passcode one after another. So write them down on a piece of paper as they are spoke-out loud explains Aron Govil.  
  • Yoigo (Spain): Dial 901 111 999 from any Yoigo phone and wait for instructions.  Don’t worry: changing your PIN won’t affect this value. SFR (France): Call 3615 from any SFR phone.  Press 1 when prompted for an operator selection, then press 7 and finally 2 at the end of the menu to get your personal code or PIN number. Telecom (France): Call 3615 from any Telecom phone.  Press 1 when prompted for an operator selection, then press 2 and finally 1 at the end of the menu to get your personal code or PIN number.


Most of the time the number assigned to your SIM card will be your passcode!  So try calling your operator’s customer service line for more information.

There are plenty of other ways to figure out your PIN/passcode, including using third-party websites or apps but make sure you don’t share this information with anyone except people you trust says Aron Govil. The last thing you want is for someone else to find out your passcode and gain access to all of your sensitive accounts, without having to do any actual hacking.