What is a PUK code? A PUK code (Pin Unlock Key) is required when you enter an incorrect PIN 3 times. After entering the wrong PIN 3 times, the card will be locked and you will need to get a PUK code from AT&T to unlock it.What should I do if my phone says Enter PUK Code? You can receive your phone's PUK code from AT&T, either by logging into your account at myWireless Account; visiting our Technical Support Chat or by calling Customer Care at 1-800-331-0500. Once your PUK has been received, it will need to be entered into your phone to set a new PIN code. If the wrong PUK code is entered 10 times in a row, the SIM card becomes invalid (permanently locked) and you will need to purchase a new SIM Card. The phone will display "PUK blocked call operator".If your device is requesting PUK 2 please call Customer Care at 1-800-331-0500.
To obtain your PUK code, log into myWireless Account and follow the steps below:
1. Select Phone & Device
2. Select the Unblock SIM Card link
3. Follow the instructions on the pop-up page
For images, see merman's post here
How to Unblock your SIM Card
You'll need your phone in hand to unblock your SIM Card.
1. First, enter the 8-digit PUK code, then press OK/Yes. Note: Some Motorola phone users will need to enter **05* if "enter PUK" is not already displayed. After
entering **05*, then enter the 8-digit PUK code and press OK.
2. Select a new PIN code, then press OK/Yes.
3. Re-enter the PIN code, then press OK/Yes.
4. If the codes were entered successfully, the phone is ready for use.For Rogers:
You must call them @ 1-888-ROGERS-1 (1-888-764-3771) and ask for 'Wireless', then 'Technical Support'. It may then ask whether it is for iPhone, BB, or other cellular. Pick other cellular (3). They will verify who you are and then will provide the PUK. Takes less than 2 minutes from making the call to entering new PIN.