What is Dual SIM, and How Does It Work?

Dual SIM allows your mobile phone to use two SIM cards or eSIMs simultaneously. This makes it easier than ever to keep your personal and work lines separate. Devices like Samsung and iPhone support this handy feature. In this article, we’ll explain how it works, guide you through the setup process on iOS and Android, and share practical tips to help you make the most of it.

Advantages of having Dual SIM

Discover the benefits of having a dual SIM card on your phone:

• Enjoy the convenience of having two SIMs in one device, so you don’t need to carry two phones.
• Stay connected with a local number without losing access to your main number, helping you avoid high roaming charges with Holafly's eSIM.
• Easily assign names to each line on your device for quick differentiation between personal and work calls.

To name your SIMs on your iPhone  

• Go to Settings → Tap on Cellular or Mobile Data → Select the SIM you want to label → Then on "Cellular Plan Label" and on CUSTOM LABEL assign a name.

To name your SIMs on your Android

• Go to Settings → Tap on Connections → Select SIM manager → Choose The SIM/eSIM you want to label → Press “Edit name and icon” → Enter the name you’d like to assign to your SIM/eSIM under “SIM name” → Press Done to apply the changes.

Troubleshooting Tips

If you want to set up dual SIM on your iPhone or Android using your main SIM for calls and your Holafly eSIM for data at the same time, follow these steps:

To set up dual SIM on your iPhone

• Go to Settings → Cellular or Mobile Data → Ensure both your SIM and eSIM are active → Select Default Voice Line → Choose your personal line → Return to Cellular or Mobile Data → Tap on Cellular Data and select your Holafly eSIM → Finally, make sure “Allow Cellular Data Switching” is turned off, so your phone doesn’t automatically switch between data lines based on signal strength.

To set up dual SIM on your Android

• Go to Settings → Tap on Connections → Select SIM manager → Ensure both your SIM and eSIM are active → In Calls, confirm that your personal SIM is selected → Choose Mobile Data and select your Holafly eSIM → Finally, make sure “Data Switching” is turned off, so your phone doesn’t automatically switch between data lines based on signal strength.

Note:  Using your primary SIM while abroad may result in roaming charges from your home carrier. They might also charge extra for calls or texts on your personal line (not Holafly). Check with them in advance to avoid surprise fees.