Do I need a new sim card to switch carriers?

This blog post tells you if you need a new SIM card to switch carriers, it also gives you information about what is SIM card and how you can switch between the carriers.

Do I need a new sim card to switch carriers?

Yes, you do need a new SIM card to switch carriers. Services with another carrier will get activated when you switch the SIM card. The SIM card stores all the information about the carrier. It uniquely identifies and authenticates the subscriber. All the carriers which work on GSM use SIM cards.

Features of GSM

  • GSM makes use of SIM (Subscriber Identity Mobile). SIM is a storage device.
  • It is available in the form of a smart card. It is portable and removable.
  • National and international roaming facilities are available.
  • Data privacy and security are maintained using encryption when the data is transmitted on-air.
  • Cryptographic keys are known to the cellular device only, which provides additional security.
  • GSM provides better frequency spectrum efficiency.
  • GSM can be made compatible with newer services.
  • Good speech quality is maintained using GSM.

Steps to switch carrier:

Step1: Confirm the compatibility of your device:

First, check the compatibility of your device with the carrier network you want to switch to. Normally on the website of the carrier the entire list of domestic phones is given, you can scan through the list and confirm. If you do not find your device on the list you can visit the carrier store for more details.

Step 2: Make sure the device is unlocked

If your device is compatible, you need to ensure it is unlocked if not contact your previous carrier and get it unlocked which is a very simple process if you have no dues and if your device is eligible.

Step 3: Buy the new carrier’s SIM card:

Now to buy the SIM (Subscriber Identity Module) you can visit the carrier store or you can get it online.

Step 4: Select a plan that best suits your needs

depending on the type of usage and type of connection choose a suitable and affordable plan for your device.

Step 5: Activate your plan

After finalizing the plan get it activated by making the payment and switching the previous SIM with the new SIM.

Why the Devices are locked with the carrier?

●   The major reason cell phones are locked is to keep users under contract.

●   If for example, you are a T-Mobile user, you will be under contract with a T-Mobile wireless carrier.

●   Under the contract, if you purchase a new i-phone, the cost of the i-phone will be broken up, and it will be added into three years contract.

●   This cost will be divided into EMIs, and it will be adjusted into the monthly bill. It will be in addition to service charges.

●   Under such circumstances, the phone will be locked with T-Mobile wireless carrier.

●   If you wish to change the carrier, you should request for unlocking your cell phone.

●   You are generally unlocking the phone means you will have to pay extra to remain out of the contract.

Meaning of locked phone

●   A locked phone is a mobile device tied up with a particular mobile carrier network.

●   If you purchase a new cell phone under some contract, it is a locked phone.

Difference between locked phone and unlocked phone

●   In the case of a locked phone, there is an inbuilt software code.

●   This process of inserting a software code is called encoding. Such locked phones are also said as encoded cell phones.

●   This code prevents getting services from another carrier.

●   So if you purchase a locked phone from a T-Mobile carrier and insert another SIM, it will not be activated.

●   The software code allows the signals only from T-Mobile carriers and not from any other carrier.

●   On the other hand, there will not be any software code for an unlocked phone.

●   Even if a software code exists for an unlocked mobile, you will get some other code that unlocks the original code.

●   This procedure of unlocking is called decoding.

Benefits of an unlocked phone

●   After discussing the locked and unlocked phones, the question arises “Are there any benefits of having an unlocked phone?”

●   The important prime benefit is that you will not be stuck up with the same wireless carrier.

●   If you have an unlocked phone, insert another carrier’s SIM card and then proceed to sign up with new services. But you need to check the carrier compatibility.

●   In this case, you don’t have to buy a new cell phone for a new wireless operator.

●   So, you can think of getting the cheapest services using the unlocked phone.

●   This provision is more beneficial if you are traveling abroad.

●   Replace the SIM card, insert a local carrier SIM card and start using the service.

●   In this case, you will get a new local number. Using it, you can make calls and access the internet. It will be much cheaper.

●   Usually, unlocked cell phones do not have unnecessary apps. 

What are the eligibility criteria to unlock a  phone?

One can unlock phone devices, provided that the following criteria are satisfied.

●   The cell phone must be sold by an authorized carrier.

●   The cell phone should not be reported as blocked or lost.

●   An account concerned with the device must be active.

●   Depending upon pre-paid or postpaid plans, the device should satisfy all necessary unlock requirements.

How to Unlock a device?

  • The following steps are used to unlock the device.
  • First, check whether your cell phone is eligible for unlocking. It mainly depends on GSM and CDMA carriers.
  •  Request customer care for unlocks code.
  • Insert a blocked SIM and switch on the device.
  •  Press the select key and enter unlock code.

 What is IMEI?

 IMEI is a special identifier associated with Global Mobile Communications System (GSM) phones. It provides device-related information

How does IMEI help carriers?

  • GSM uses subscriber identity module cards to store subscriber’s information.
  • Customers can easily switch the SIM card from one device to another and start making calls without any problem
  • It helps operators identify valid customers and disable the devices from their end if reported lost or stolen.
  • IMEI is hardcoded by the manufacturer it helps the carrier understand the capabilities of the device it helps the provider to get the device to a nearby tower for connection.
  • If you lose your phone or if it gets stolen IMEI will help you make sure the person who stole it, won’t be able to use your device. The device can be denied service to any cellular network even if the SIM is changed.

Steps to check your IMEI number on your Mobile:

  • From the Home screen, select Main Menu.
  • Scroll to and select Settings.
  • Scroll to and select Phone Settings.
  • Scroll to and select Phone info.
  • Scroll to and select Version info.
  • Scroll to and view the IMEI.


On the dial pad screen, press *#06#, and you will see the IMEI. Some phones require you to press send key after the code.

Frequently Asked Questions(FAQs): Do I need a new SIM card to switch carriers?

What do I need to switch phone carriers?

You need a valid ID, an account number associated with the number, Carrier PIN, or Passcode:

Can I change SIM cards with the same carrier and keep my old number?

Yes, you can change your SIM card and keep the same number, you just need to contact your new subscriber and let them know that you want to port your old number, SIM will be new but the number will be the same.

Do I need to unlock my phone to switch carriers?

Yes, you need to unlock your phone if your phone is locked to your previous carrier.

You can ask your previous carrier to unlock your device, it will be unlocked free of cost if your device is eligible for unlocking

Can I keep the same number if I switch to T-Mobile?

Yes, you can keep your number if you switch to T-Mobile, you can either use the same carrier if the device is unlocked and both are compatible or you can port your number to T-Mobile.


This blog post explains to you how you need to change the SIM when you want to switch the carrier, what is SIM, and how IMEI is important when you change the carrier. you will also get information about how you can unlock the device before switching the carrier.


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