Using One SIM Card With Two Phones: How to?

Here’s how to use one SIM card with two phones:

One SIM card cannot be used with two phones at once because it’s obviously physically impossible for one SIM to be in two devices.

Even though it’s not a physical card, it’s not possible with an eSIM either.

Nonetheless, you can usually use one SIM card with two phones by swapping the SIM card between them.

If you want to learn all about using one SIM card with two phones, then you’re in the right place.

Let’s jump right in!

Table of Contents

How to Use One SIM Card With Two Phones?

A SIM, or “subscriber identity module,” is a small circuit board card that goes inside your phone. 

Mobile network companies use SIM cards to identify phone owners. 

Because the purpose of a SIM card is to act as an identification unit, each SIM card is unique.

Mobile phone and sim card.

It’s impossible to use one SIM card with two phones simultaneously because it’s obviously physically impossible for one SIM to be in two different devices at the same time. 

Even with an eSIM, it’s not possible even though it’s not a physical card.

eSIMs can only be installed on one device, and most can only be installed once, so if you remove it from your device, it won’t work again.

How to Use One SIM With Two Phones?

So, you have a single SIM that you want to use on two different phones. 

Right out of the gate, I should make it clear that it’s physically impossible to use one SIM on two different phones simultaneously.  

It is, however, possible to use a single SIM card on two phones, so long as you do so one at a time. 

Female hand holding sim card.

This can simply be done by taking out your SIM card from one phone and inserting it into another. 

This should work for most phones. You can swap out SIM into different phones whenever you feel like it. 

People usually do this when they keep one phone for work and one for personal use. They may have a cheaper phone for going out clubbing, for instance, to ease the financial sting in the case of a loss.

An important thing to note is that swapping the SIM won’t work if the phone is locked. 

This is when cellular network companies restrict a phone to only work on their network. 

In that case, only SIM cards from that particular company work on that phone.

Modern mobile phone with chain locked, restricted concept.

For example, let’s say your SIM card is from AT&T. 

The phone you are just plugged your SIM into is locked to Sprint. 

In that case, your SIM card won’t work because the phone only accepts SIM cards by Sprint. 

Cellular network companies do this mostly for phones that are bought on a plan from the company.

 So, if your phone is on a similar plan, make sure the SIM you are inserting is also from the same company. Otherwise, it won’t work. 

What Happens if One of Your Phones Is Locked?

So, what if your phone is locked? 

What do you do then?

Attractive smiling woman talking on the phone at home.

Well, you have a few options to unlock your phone and use a SIM from a different carrier. Here are some of the ways you can get your phone unlocked:

  • Ask your carrier to unlock your phone for free: Surprisingly, this actually works. You just need to contact the cellular network carrier that has locked your phone and see if you’re eligible to get your phone unlocked. If your initial contract is up, then it will be done easily. On the other hand, you might have to pay if your contract is still ongoing. 
  • Pay a third-party site to get it unlocked: If your cellular network is not unlocking your phone, you can try to get it unlocked via a third-party website. This is a little risky because you might void the warranty on your phone if you do it. You also have to be careful while doing it because there are a lot of scammers out there. 
Woman holding smartphone looking frustrated with pursed lips.

Either way, both your phones need to be unlocked if you want to use one SIM card with two phones. 

Dual SIMs or Secondary SIMs, How Do They Work?

Some networks provide secondary SIMs that are basically identical SIMs that you can put in a secondary device such as another phone. 

Secondary SIMs only receive a call when your primary SIM is shut off.  

In that case, the call is diverted to the slave SIM. 

You’ll have to check if the network provider in your location offers a similar service. It is sometimes also called dual SIMs.

A female hand holds a dual SIM card slot.

SIMs are designed to be unique so that they serve as digital identities. 

Cellular network operators use SIM cards to know where and to whom they should direct a call. 

If there are two SIMs active on two different devices, the cellular company won’t know where they should forward the call. 

This can become very confusing and inconvenient. 

This is why SIMs are designed to work on a single phone at a time. 

How to Use Two SIMs on One Phone?

What if you want to do the opposite? 

That is, what if you want to use two SIM cards in a single phone?  

Nowadays, a lot of phones come with SIM trays that can accommodate two SIM cards. 

Dual SIM card slot.

Just put both your SIMs into the tray card and pop the tray back into your phone. 

That’s it. Your phone now has two working SIM cards on the same phone. 

This means that your phone has two numbers, so texts and calls for both numbers can be viewed and received on a single device.