The default number should be on your SIM card packaging. You may be locked out of your account after multiple attempts with an incorrect SIM card PIN, so keep the packaging handy. Go to Settings > Security > More security settings. Tap SIM card lock.
Each operator has a default passcode, usually 1111, 0000, or 1234.
This is called a SIM PIN (personal identification number). Typically the user would use the GUI of the phone to enable the PIN. Some manufacturers have a default PIN value set with new SIM cards. Numbers such as 0000, 1234, or the last four digit of the cell phone number (MSISDN) are common.
On your SIM packaging
Your PUK code is the 8 digit number found on either the SIM or the additional SIM packaging.
The PIN is an acronym for Personal Identification Number and represents an access code made of four digits. When you buy a SIM card, you also receive a PIN for it. You need this four-digit code to enable the SIM card once you have inserted it into your phone, to be able to access your operator's mobile network.
If you enter your PIN (Personal Identification Number) code incorrectly several times, the SIM card is locked.
Find your PUK on the SIM card pack
If you've still got the little pack that the SIM came in, check on the credit-card sized bit of plastic that the SIM snapped out from. The PUK Code is an eight digit number, and is usually printed on the back.
Generally, you need PUK number to unlock SIM when it gets locked. But luckily, there are still ways for you to unlock SIM card without PUK. You can always ask your service provider to help you after confirming your identity. And even if you fail, professional SIM unlock tools are still there to help you.
You can try online to find your PUK code as long as you have an online account through your network provider (most offer this service). Log in to your mobile phone account on your computer and look for a PUK code section on your account page. Where this appears will vary among network providers.
Getting a PUK Code
Your carrier can provide you with the PUK code for your SIM card. You can sometimes find this on your carrier's website after you log in, and you can usually also obtain it by calling customer service or taking the phone to a carrier store.
If you know the password, enter it to unlock your SIM. If not, you can unlock the SIM with a PUK (pin unlock key) that comes from your mobile provider. The default SIM unlock code for T-Mobile and Sprint is 1234, while the default unlock code for Verizon and AT&T is 1111'.
Only your carrier can unlock your iPhone. Contact them and request an unlock. After you submit the request, it might take a few days to complete. Contact your carrier to check the status of your request.
You can remove a SIM lock on your Android device in simple ways. You can look for your carrier's contact and ask them to give you an unlock code to bypass a SIM lock. But this happens only if the SIM card is locked to a network. You can still use an IMEI number or input a PUK code.
What is the default PIN? The default PIN is set to 0000.
One final security tip for eSIMs applies to iPhone users specifically, and that's to turn on SIM Pin. SIM Pin requires you to enter a PIN every time you make a phone call or use cellular data.
Your PUK (Personal Unlocking Key) is an 8-digit code unique to your SIM card. If you don't know your SIM PIN, you can use your PUK code to unlock your mobile and reset your SIM PIN.
Cell Unlocker is an online SIM unlock services that unlocks your phone in just a few simple steps. You need to enter your phone's model information and IMEI to unlock a SIM.
The PUK (Personal Unblocking Key) code is a code consisting of 8 digits. It is used to unblock your SIM card when you entered 3 times a wrong PIN code. A card blocked by the PUK code cannot be unblocked; it cannot be used any further and you have to replace it.
A PUK code is a security feature on your sim card that, where you can choose to have your sim request a PIN code when your phone is switched on. If this code is entered incorrectly three times, your sim card will lock itself, and this can only be unlocked using your PUK code.
If a SIM PIN security code has been entered incorrectly multiple times, the SIM will lock and require you to enter a PUK code to use your device again. Be careful! If you incorrectly enter your PUK code 10 times, your SIM will need to be replaced.
In some cases, the only thing you need to unlock your phone is a software update your carrier will push to your device, and then you insert the new carrier's SIM card and you're good to go. Or you might need to enter an unlock code provided by your current cell phone company before you can install a new SIM card.
Yes, it is legal to unlock phones. More importantly, the FCC has mandated that all carriers should unlock phones for their consumers for free if a consumer so desires. That said, you need to know whether your phone can be unlocked. The FCC isn't giving you a free pass to con the carriers.