If you enter your PIN (Personal Identification Number) code incorrectly several times, the SIM card is locked. You then need the PUK (
SIM card protection. You can lock and unlock each SIM card you use on your device with a PIN (Personal Identity Number). When a SIM card is locked, the subscription linked to the card is protected against misuse, meaning that you have to enter a PIN every time you start your device.
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).
To prevent unrestricted access to your privacy
However, in some cases, the thief might want to access your phone, especially if the thief is someone close to you and is directly interested in your private life. Without an active SIM PIN, he or she might be able to listen to your voice notes or read your messages.
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.
Click Settings. Select Security. Select Set up SIM card lock. Toggle the SIM card lock feature On or Off.
The best way to quickly check whether a mobile phone is locked or not is to slip the SIM card out, and put in one from another network. If it can make calls, send texts, and connect to the internet, that means your phone is unlocked. Just make sure that the two SIMs don't actually connect to the same network.
SIM card lock protect your SIM from being used on other Mobile Devices.
SIM lock is the highest security provision of a hand set. If you activate SIM lock, then you can use only that SIM (which is present during SIM lock activity) with the handset and if you insert any other SIM, then you need to provide the SIM lock password.
Each operator has a default passcode, usually 1111, 0000, or 1234.
“SIM card locking” is a misnomer - SIM cards don't get locked. Phones get SIM-locked. The phone is locked to a specific carrier's SIM cards.
Never try to guess a SIM PIN or PUK code. The wrong guess can permanently lock your SIM card, and then you would need a new SIM card. If your device asks for a PIN or code that you don't know, here's what to do: Contact the carrier that gave you the SIM card.
The reason many network providers SIM lock their phones is that they offer phones at a discount to customers in exchange for a contract to pay for the use of the network for a specified time period, usually between one and three years.
If you have gotten the phone SIM unlocked (either officially by the carrier or unofficially through a 3rd party), then it will be permanently unlocked FOREVER. A factory reset will NOT remove the SIM unlock of the phone. Once you have the phone SIM unlocked, it will stay unlocked for good.
How to unlock a phone without the PUK Code? Unfortunately, there is no option for you to manually unlock your phone if forgot your PUK Code. The only option left is to call the customer support of your internet service provider to request unlocking your SIM Card.
The PUK (Personal Unblocking Key) code is usually an eight-digit unique number assigned to a SIM card and is available as a security feature for all SIM cards. Most mobile phones have a PIN (personal identification number) designed to prevent unauthorized usage of your phone and keep SIM details safe.
SIM Network Unlock Pin (NUP) is a code used to unlock an Android phone or iPhone from its original carrier so that it may be used on other carriers. This code is typically 8 or 16 digits long and is used to unlock a smartphone.
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).
If unavailable, ensure a SIM card is properly inserted. The default SIM PIN is 1111.