A SIM card gives you the ability to have conversations and send text messages around the world. It's also a gateway to your bank account, social media, and other personal information. In case of phone theft, you can block your SIM card quickly by contacting your carrier. However, you may realize it too late, after the damage has been done. You can add an extra layer of security to protect your SIM card on Android if your device has a SIM card slot.
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The SIM card lock feature has existed on the best Android phones for years. After enabling it, you'll enter your SIM card's four-digit passcode after rebooting or when it's transferred to another phone.
How to set up a SIM card lock on Android
Setting up a SIM card lock requires you to enter the default passcode set by your operator. In most cases, the passcode is either 0000, 1111, or 1234. To keep your SIM from being locked after three tries, look for it on the plastic card that held your SIM. Be extra careful, as three failed attempts blocks your SIM card. Then, you'll need to contact your carrier to unblock it.
- Got to Settings > Security > More security settings.
- Tap SIM card lock.
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- Turn on Lock SIM card and enter the default PIN if you're enabling it for the first time.
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- Once enabled, tap Change SIM PIN to change the default PIN.
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- Enter your old PIN, enter your new PIN, and tap OK. Be extra careful while entering your old PIN. Entering the wrong PIN three times blocks your SIM.
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- To test the feature, reboot your phone.
When the SIM is transferred to a different phone, irrespective of whether it's an iPhone or Android, you can't use it until it's unlocked. Here's what you see when you insert your locked SIM into another iPhone or Android device.
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The process of enabling SIM lock may differ from one phone to another. No matter which phone you have, use the search box in the Settings app to search for SIM lock and enable it.
Other ways to protect your SIM card
Scammers use SIM phishing, also known as SIM swapping, to gain access to your SIM card and gain control of your phone. For this, spammers collect as much of your personal information as possible from your social media and other accounts online. Then they trick your carrier and its customer executive into believing you contacted them and asked them to transfer your number to a spare SIM card they (the scammer) own. So, if you have personal information that's set to public on social media websites, take it down. Although these attacks are rare, it's better to be safe than sorry.
There are other ways to protect yourself and your phone. If you get too many spam calls, learn how to block spam calls on Android. And find out how to spot and report phishing emails to help keep yourself and your community safe.
If your phone uses a SIM card to operate, you can activate a security feature called a SIM PIN. The SIM PIN protects your SIM card from unauthorized use, and must be entered in order to use your phone. Enter it incorrectly three times and your SIM card becomes locked. You can unlock your SIM card on your own, however, by typing in a PIN unlock key. Your carrier can provide you with the unique PUK code for your device.
Step 1
Contact your wireless carrier by calling the toll-free customer service number. (Find this on your provider's website or a recent invoice.) You will need to verify your account password before the PUK code is released to you.
Step 2
Power your phone on. You will see a "SIM Locked" or "Enter PUK" message. Type in the eight-digit PUK code and press "OK."
Step 3
Type in a new four- to eight-digit PIN code when prompted, then press "OK."
Step 4
Verify your new PIN code by re-entering it when prompted. Press "OK." Your SIM is now unlocked.
References
- AT&T Wireless: Answer Center--What Should I Do If My SIM Is Blocked?
- AT&T Wireless: Answer Center--What Is The Difference Between A Device Lock Code, A SIM PIN and A PUK Code?
Warnings
- If the PUK code has been entered incorrectly 10 times, your SIM card is permanently locked. You will need a replacement SIM card.
Writer Bio
Amy McClain has worked as both a feature writer and a copy editor for a prestigious daily newspaper. She also enjoys writing as a hobby and takes creative writing courses in her free time. She has worked in sales and marketing for a wireless company for over seven years.