A personal unblocking key (PUK), sometimes called personal unblocking code (PUC), is used in SIM cards to reset a personal identification number (PIN) that has been lost or forgotten. Most mobile phones offer the feature of PIN protection.
When you purchase a SIM card, it comes in a little package, and the PUK code should also be included in it. If you still have the package, look for the plastic card that the SIM was snapped out of. The 8 digit PUK code should be printed on the back, together with the SIM PIN code.
If you forgot or don't know your SIM PIN
Contact the carrier that gave you the SIM card. If you aren't sure which carrier to call, remove your iPhone SIM card or iPad SIM card and check the card for the carrier's name or logo. Ask your carrier to help you unlock your SIM card using the default SIM PIN or PUK code.
A PUK is required when you want to unlock a phone. You'll need one in the event that your handset is locked by your current network and you want to use a SIM card from another network. You'll also need to get a PUK code in the event that you mistakenly enter the wrong PIN code and you are automatically locked out.
Your actual SIM also has a series of numbers printed on it. Your PUK code is the 8 digit number found on either the SIM or the additional SIM packaging. By default, your PIN code is the last 4 digits of your PUK code – but obviously if you've changed your PIN code yourself, this will no longer apply.
In order to unlock it, you'll need your 8 digit PUK code. Though they are usually used by mobile providers to unlock a phone after its security measures have been triggered, a PUK code can also be used to remove a network restriction from a phone.
PINs are not the same as passwords because they are generally tied to the devices you use.
Each operator has a default passcode, usually 1111, 0000, or 1234.
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.
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 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 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'.
This can be done with most Android smartphones, and only Samsung phones have the ability to unlock through a settings menu. If you have a Samsung phone 2019 or later, head to Settings > Connections > More Connection Settings > Select Network Unlock.
You can remove the SIM lock by performing an unlock procedure on the phone. Although the specific unlock instructions differ according to your phone model, the procedure consists of obtaining an unlock code from your existing mobile provider. You can also buy a code online if the provider is unable to give it to you.
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.
Most SIM cards use a four digit PIN. Others can use five or six digits. To override a lost, forgotten, or improperly entered user PIN, manufacturers also have a personal unlocking key (PUK).
The SIM card on your mobile phone will become locked if you enter an incorrect personal identification number (PIN) three times. You won't be able to use your phone, except for emergency calls. To unlock it you must reset your PIN by entering your SIM card's unique unlock key (also called a PIN unblocking key or PUK).
Someone who obtains your online password can sign in to your account from anywhere, but if they obtain your PIN, they'd have to access your device too. The PIN can't be used anywhere except on that specific device. If you want to sign in on multiple devices, you have to set up Hello on each device.
The password is used to log in to the mobile app. You will rarely need to enter your password because the app will normally be running in the background of your smart device. The passcode is a four-digit PIN, and it is an optional, added-security feature that you can enable inside the app.
If you cannot find it, give your mobile network a call, and customer support will be able to give you the PUK code or generate a new one after you have answered some security questions. The network provider is going to ask you to prove your identity.
Unlocking a phone can also make things easier when you're traveling abroad or trying to get the most money back when selling it. It isn't hard to unlock your phone—and it's completely legal and free—but a little help can go a long way, because the process varies from phone to phone and carrier to carrier.
The most reliable way to check if your device is unlocked is by swapping your current SIM card for another carrier's SIM card. Depending on the make and model of your device, you may need a SIM card eject pin or something similar to remove your SIM.