Microsoft Lumia User Manual page 128

PUK
Security code (lock code, password)
(min. 4 digits)
IMEI
© 2015 Microsoft Mobile. All rights reserved.
If you forget the code or it isn't supplied with
your card, contact your network service
provider.
If you type in the code incorrectly 3 times in
a row, you need to unblock the code with the
PUK code.
This is required to unblock a PIN code.
If the code is not supplied with your SIM card,
contact your network service provider.
This helps you protect your phone against
unauthorised use.
You can set your phone to ask for the lock
code that you define.
Keep the code secret and in a safe place,
separate from your phone.
If you forget the code and your phone is
locked, your phone will require service.
Additional charges may apply, and all the
personal data on your phone may be
deleted.
For more info, contact the nearest care point
for your phone, or your phone dealer.
This is used to identify phones in the
network. You may also need to give the
number to your care point services or phone
dealer.
To view your IMEI number, dial *#06#.
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