Lock Code, Pin Code & PUK code

Lock code:
1. 5 digits, Used to prevent unauthorized access to certain functions on the phone
2. Where: Tools > Settings > Security > Phone & SIM
3. Default: The default lock code for Nokia Series 60 devices is 12345.
4. Forgotten - If you've changed this code and forgotten it - you will need to visit a Nokia authorized service center, who will be able to reset the lock code for you.

PIN code
1. 4 digits, an optional 4 digit code to protect your SIM
2. where: Tools > Settings > Security > Phone & SIM
3. Forgotten -If you keep trying, you'll eventually get locked out and need to contact your network operator for a PUK code

PUK code
1. 8 digits, You'll be asked for this 8 digit code if you've entered the wrong SIM code more than the allowed number of times. You'll need to contact your network operator to get this lock lifted.