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What does a locked SIM mean?

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  • 4 min read

Buying a new SIM card every day is something you may have seen in spy thrillers or comedies. However, if you are visiting a foreign country and want to use a local SIM card, then you may face a problem with connectivity. This happens because your phone is locked to a sole telecom provider who does not want you to switch network

In this article, we will discuss what a locked SIM card entails and other frequently asked questions.

Also read: How to unlock a SIM card without PUK code?


What is a locked SIM?

A SIM lock is also called a network lock in which companies that provide phones, especially in bundled packages, lock the software of those phones with a particular SIM. It ties the device to its network. So when a device has been SIM locked, it means that you can only use that device with a SIM card that is sold by either the carrier that sold the phone or with another carrier’s authorised SIM card.

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If you find that your device is SIM locked, then it will not be able to switch to another carrier’s SIM card unless you unlock the SIM card. Your device will show an error message and you will be unable to access the network provided by another company. Your access will be limited to some countries or anywhere the network is provided by the company or the affiliated telecom provider that has locked your device’s SIM.


Why are devices locked?

To ensure that a customer remains loyal for a certain duration, companies decide to lock SIM cards. They also aim to make their customers stay with the network for a longer duration or until the contract expires. Even for the duration while you wait to pay off your phone, your SIM might remain locked. This lock keeps a customer latched in one place, unable to leave the company’s plans.

Locked phones might also be relatively cheaper than unlocked phones as it makes sure the carrier makes up for the discounted price through the locking system. Then the customer is forced to use the SIM card sold by the carrier company. When you purchase locked devices, the SIM card comes with the device.


How does a SIM lock work?

A SIM lock is a software restriction, hence codes are embedded in the operating system or firmware of your device. When you switch on a phone with another carrier’s SIM card, then your phone scans for a SIM lock code. If the code is similar to the carrier’s restriction, an error message will be displayed and you will not be able to use that SIM card.

With the insertion of the correct SIM card, the phone will register with the network carrier and allow you to make calls, send and receive messages as well as access mobile data.


Can you unlock a SIM lock?

If you wish to sell your locked mobile phone or gift it, then you may face difficulties as people prefer unlocked phones. Depending on the mobile carrier whose device you are using, you can either go to the settings to find an Unlock option or head to their official website. You can even contact your carrier’s customer support to request a SIM unlock pin or code. You can disable the SIM PIN option on your device’s Mobile Data settings to remove the SIM pin or lock.

So mobile network providers will agree to unlock your SIM if requested, whereas some of them have a mandatory period of keeping the SIM under lock for a few days after the initial device purchase. You can also use third-party services to unlock your SIM which might cost a bit. However, it could also cause you more harm than good as your information could be stolen or other legal issues might crop up with your service provider.

Also read: What is SIM toolkit? All you need to know

Sania Usmani

Sania Usmani

Always curious, calm, and a little crazy, you can find me daydreaming or studying. An avid reader, traveler, and graduate of Aviation Science, I love gaining new experiences in life and star gazing. You can contact her here: sania_5008@proton.me

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