Codes and Passwords

Mobile phones offer a wide range of passwords and PINs to provide you with a level of security. Here's our guide to understanding them:

1. Keylock

This option locks the keys when the phone is not in use, guarding you against making calls by accidentally pressing buttons. To turn this service on and off, you will need to press a sequence of keys (for example [menu] then *), or some handsets can be programmed to turn the keylock on automatically if the phone has not been used for a certain length of time.

2. PIN Code

The PIN (Personal Identification Number) code protects your SIM card against unauthorised use. When the PIN code request is enabled, the code is requested each time the phone is switched on. This will protect your account, even if your SIM is put into another handset.

The PIN code is usually supplied with the SIM card, but may be set to a default code (often 0000 on Vodafone, 5555 on O2). You should change this as soon as you get your SIM card, but make sure you don't forget the new code. If you enter an incorrect PIN code three times in succession, the SIM card is blocked, and you'll need to enter the PUK code.

2. PIN Code 2

The PIN2 code, supplied with some SIM cards, is required to access some functions, such as the fixed dialling list (a restricted list of numbers the phone can call). These functions are only available if supported by your SIM card.

The default PIN2 is set by the Service Provider, and again, you should change it as soon as you get the card. If you enter an incorrect PIN2 code three times in succession, you'll need to key in your PUK2 code.

3. Personal Unblocking Key (PUK)

If you enter the wrong PIN code for your SIM three times in a row, the SIM will lock, requiring you to enter the PUK to release it. The PUK code may be supplied with the SIM card. If not, contact your service provider for the code. Don't try to guess the PUK, this may permanently disable your SIM.

4. Personal Unblocking Key 2 (PUK2)

This performs the same function as the PUK, but for SIM PIN 2. If you lose the code, contact your service provider.

5. Phone Security Code

This security code locks the handset, as opposed to the SIM card, and you will need to key in the code whenever a new SIM card is inserted in the phone. Whilst some handsets will accept incoming calls with this lock enabled, many will require the code in order to answer a call.

The default code varies according the handset make and model (for example, Nokia 3310 uses a code of 12345), and should be changed as soon as possible.

6. Barring Password or PIN

The barring password is needed when using the Call barring service function. The default code is set by the network (0000 or 1919 for Vodafone, 1111 for Orange, 0000 for O2); contact your service provider for further details.

7. Voicemail PIN

This is a code that you will secure the voicemail service on your mobile phone account. If you do not set a voicemail PIN, you may not be able to access voicemail from anywhere but your own mobile phone.

Some providers set a default pin (3333 on Vodafone, 8705 for O2); you MUST make sure that you change this default code, otherwise other people will be able to listen to or delete messages left for you.

8. Master Reset Code

This code will allow you to unlock a handset if you have entered the Security Code wrongly too many times. You should ask your Service Provider for this code when you need it.

9. Blacklisting

If you have had your mobile phone stolen, your network should add the IMIE (International Mobile Equipment Identity) number of your phone to a database of mobile phones that have been reported stolen. Once a phone is on this list, it will not be allowed to use any of the networks.

Do bear this in mind when buying a second hand phone – you may end up with a mobile that is permanently disabled.