To unlock your SIM Card, reset the PIN by entering your SIM Card's unique PUK (PIN Unlock Key). Note: Entering an incorrect PUK (PIN Unlock Key) 10 times will permanently lock your SIM Card. If the SIM Card becomes permanently locked, you will need to swap it for a new SIM Card.
To protect your SIM card from others using it for phone calls or cellular data, you can use a SIM PIN. Then, every time you restart your device or remove the SIM card, your SIM card will automatically lock and you'll see "Locked SIM" in the status bar. Don't try to guess your SIM PIN.
If a phone demands an unlock code to access it, it has nothing to do with a SIM card whatsoever. This lock can be removed by entering the right code on an Android phone or by having Apple unlock it for an iPhone.
The 8 digit PUK code should be printed on the back, together with the SIM PIN code. Your mobile provider should have similar packaging for the SIM card. The PUK code is printed on the plastic card holding the SIM. If you can't see the PUK on the back, you might have to reveal it.
If you're willing to unlock the phone on your own, here's what you need to know. And carriers such as T-Mobile offer apps that unlock phones. Before you unlock your phone, though, make sure it's compatible with the new carrier's network. Verizon and Sprint use a standard called CDMA, and AT&T and T-Mobile use GSM.
Some iPhones will only work with a SIM card provided to the carrier they're locked to – O2, EE, Three or Vodafone, for example. Unlocking your iPhone is completely legal if you purchased the device unsubsidised or have finished paying for your contract.
If your carrier doesn't offer up the default PIN, most often it's either 0000 or 1111. But remember, you get three attempts. If the three attempts fail, you must enter the PUK. Without that PUK, your device will not be able to access the SIM card.
Reset your pattern (Android 4.4 or lower only)
- After you've tried to unlock your phone multiple times, you'll see "Forgot pattern." Tap Forgot pattern.
- Enter the Google Account username and password you previously added to your phone.
- Reset your screen lock. Learn how to set a screen lock.
Sim cards can go bad by frequent removal and insertion from/into mobile phone, As the sliding process damages the chip lines and finally you can't use that.
What does it mean when a phone is locked? When a handset is locked it means it will only work with the provider from whom you bought it. If your phone is locked it won't automatically become unlocked when your contract expires with your provider. You'll have to specifically ask your carrier to unlock it.
On stock Android, open the Settings for your smartphone or tablet and tap on Security.
- Access Security Settings.
- Go to the Advanced section.
- Access SIM card lock.
- Select the SIM card whose PIN you want to change or remove.
- Tap on Biometrics and security.
- Access Other security settings.
- Access Set up SIM card lock.
Locking a phone's SIM card isn't a new concept. It's a basic security feature on pretty much all phones, including Android ones. A SIM card lock won't prevent a thief from swapping out your old card for a new one but that's okay, at least you know they can't use your phone or your precious data.
You can take the SIM card out, put it into another phone, and if someone calls your number, the new phone will ring. If the SIM card and phone serial number don't match, the phone simply won't work. The SIM card won't work in other phones, and the phone won't work with other SIM cards.
How can I unlock my device? Eligible customers can request a domestic SIM unlock and/or request the associated MSL Code by contacting Boost Mobile Customer Care at 1-888-BOOST-4U 1-888-BOOST-4U FREE .
