Invalid SIM Card [Fixed] – Network Locked SIM Card Inserted


By Jack Lin

Update on

Invalid SIM Card
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Any restraint from the carrier service can be very annoying. A function will be accessible for the user to use in one minute, but some minor changes will block the function.

Something as simple as changing your SIM can wind you up with a message saying, ‘network Locked SIM card Inserted.’ Let’s see how to fix this issue with ease.


It can be very frustrating if you have important content stored in the SIM card you want to use, but the network-locked SIM card is inserted, or an Invalid SIM card error pops out of nowhere.

There is only one thing if you want to get rid of this invalid SIM card error off your phone. The solution is to understand what the problem is.

The problem will be a network-locked SIM card inserted error in this case. To find the right solution, we need to go a little deeper into the problem. The first thing we have to know is what causes the error. How to prevent it from happening again? And finally, how to stop it?

This article will go to great lengths, providing you with all the information you will need regarding the error network-locked SIM card inserted error and how to fix it properly.

Why ‘Network Locked SIM Card Inserted’ Error Message?

If you see this message on your phone, then there are two possible reasons why the SIM card decided to show an invalid SIM error. One is due to Network Lock, and the other is Regional Lock. Let’s take a look at both of these things to understand the problem a little better.

Also, if you are looking for the latest new ICCID codes for your iPhone updates, this article reveals the latest list of ICCID codes in 2023 for you.

Network Lock

This kind of lockage will be triggered by the network carriers themselves. Network lock will stop your phone from using network services if your current SIM card is not the original SIM card that came up with the phone. You have to meet specific requirements made up by the service provider to get rid of this error.

Many people, when they buy a new phone, do it in installments so that they won’t feel a heavy impact on the back right away. Due to this reason, many people buy their phones by staying under a contract with the carriers.

When they sign a contract with the network carriers, they don’t have to pay the full price of the phone at the time of the purchase, as the customer will pay the price of the phone in monthly installments.

If you choose to go with another carrier service by switching to a different sim, you might get the Network Lock error on the screen. These carriers will implement this lock in the phone; if the user is still in the contract with the carrier service and decides to jump to another ship, they will see the network lock error. This could be one of the reasons why you see a network-locked SIM card inserted error on your phone.

Region Lock

Unlike network lock, where the lock gets implemented by the service providers. Here the picture is a little different. A region lock comes with the manufacturer of the phone.

If your SIM card belongs to a specific region or country, then you might see a ‘Region Lock’ error on your screen. In order to work any sim on the phone, you have to use the sim based on the region or country you are in to start using network services again.

Fixing the Problem of Invalid SIM Card

The error can be very persistent on the phone, but there are ways to fix it. If you look for a solution online, you will come across plenty of software promising to fix the problem.

But most of them are fake and will charge you plenty of money to do so. There is no way of knowing which one of the software has the technology to figure out the solution. It can get very difficult to find the right software to fix your problem.

So we have compiled the software list to a few. This software will fix your problem by making it worse.

1. From Your Carrier Service

The lock has been implemented on the phone so the customer won’t back away from the contract they signed with the carrier service. If you meet the demands or requirements of your carrier service, then they can easily get rid of the invalid SIM card error for you to use effectively without relying on additional websites or software.

The requirement will differ from one carrier service to another. But most of the requirements from the carriers are:

  • The user must complete the full payment of the smartphone
  • You must use the phone for more than 3 or 6 months.

Once you meet the requirements provided by the service carriers, you will receive your network code via email or in a message.

Once you receive the message containing the code, then follow these steps to activate the number back again.

  1. Turn down your phone.
  2. Please take out the older SIM card from your phone, and insert it with the new one you want.
  3. Turn the device back on.
  4. You will be asked to input a code to activate the sim upon launch. Here you insert the code that was sent to you via msg. After a few seconds, the network will be up and running.
  5. That’s it! You are not going to see an invalid SIM card anymore.

2. Fix ‘Network Locked SIM Card Inserted’ via DoctorSIM

DoctorSIM is a legal method to unlock your invalid SIM card in a matter of hours without going through the technical stuff behind the scenes to execute the technique. Here are the steps you need to follow to activate the lock on the network.

  • Open your browser and click to open ‘
  • Once you enter the website. Here all you have to do is select the proper brand name of your device.
  • Now there are certain things you should have with you because you will need them later in the future steps. Your phone’s IMEI number is one of the important pieces of information that will help you unlock the sim. If you don’t know the IMEI number of your phone, you can get that number by pressing *#06# on the keypad.
  • After you select your phone’s brand name, you need to input the information about your service provider and the country.
  • Once you have given this information, the next step is to select the plan.

DoctorSIM Price Plan

  1. Low-Cost Plan – This will be a cheaper option to unlock the network; the success rate will vary. Here the code will get searched in the local parameter.
  2. Premium Service Plan – This plan will be a little bit expensive, but then you would also double the success rate compared to the previous plan. Here the search zone will get expanded to the worldwide level.
  3. Premium Expert Service – This is where the latest technology will get used to unlock the network code. It will be more efficient and faster.

The low-cost plan may feel like a better option, but the success rate of finding the code will not be in the zone. Going for the premium plan is recommended to get a higher success rate as the search zone gets wider, giving better results.

If you pick the low-cost plan and DoctorSIM unable to find the right code to unlock your network-locked SIM card inserted error, the money you invested will be refunded. You are not losing money by picking the low-cost option at all.

  • After you have selected a proper plan to begin the work, the next step is to provide information to start the actual process. Here you have to input your IMEI number and email. And if you want to get notified by message, there is also an option.
  • Once you have selected everything you need, all you have to do is wait for a couple of minutes before you can unlock your sim. The code will get sent to you via email or message.
  • Then you can use the code to unlock your device. That’s it
Fix network locked sim card inserted with DoctorSim


1. What does ‘Invalid SIM Card’ mean?

It means that your phone can’t recognize the SIM card inserted into it.

2. What can cause an ‘Invalid SIM Card’ error?

Potential causes include software glitches, a faulty SIM card, network problems, or a network lock.

3. How can I fix an ‘Invalid SIM Card’ error?

Simple solutions include restarting your device, cleaning your SIM card, and checking for proper insertion. More advanced fixes involve network unlocking, contacting your service provider, or even a factory reset.

4. What is a ‘Network Locked SIM Card Inserted’ error?

This error occurs when a device is locked to only function with SIM cards from a specific network provider.

5. How can I fix a ‘Network Locked SIM Card Inserted’ error?

Unlocking is typically done through a code provided by the original network provider.


Seeing any error, whether the error is something minor as can’t change the wallpaper to major or a network-locked SIM card inserted error, each of them may not share the same priority, but they do have one thing in common.

Which is the solution to fix the error by its root? The only way somebody can know the solution to a problem, such as an invalid SIM card error is by finding out what the problem is?


10 years of experience in information and computer technology. Passionate about electronic devices, smartphones, computers, and modern technology.