How To Set The SIM Used For The Data Connection On Your Windows Phone

If you have used a dual SIM smartphone you may know that most mobile platforms don't allow you to use both SIMs for the Internet connection, simultaneously. On a dual SIM smartphone, you need to use the SIM that's used for the data connection. The data connection on the other SIM is not used. Here's how to set the SIM for the data connection, on your Windows Phone dual-SIM smartphone:

NOTE:For this guide we used Microsoft Lumia 535 Dual-SIM with Windows Phone 8.1 and the Lumia Denim update. The process is the same on all dual SIM smartphones with the Windows Phone 8.1 operating system.

How To Select The SIM Used For The Internet Connection

First, you need to go to the Settings screen. Slide your finger from the top of the screen downwards, in order to reveal the Notification bar and tap the All Settings section.

Alternatively, you can open the App list and tap the Settings application.

In the System tab of the Settings window, tap on cellular+SIM.

Now, your screen should look like the capture below. Here, tap the SIM for data connection section.

Then, choose the SIM you want to use for the cellular data. As you can see in the picture below, we switched the Internet connection from SIM 1 to SIM 2.

NOTE: For a very short period of time after your selection, the smartphone will switch to Airplane mode in order to set the new option. Don't worry when this happens. It is normal behavior.

Now, your Windows Phone device will use the data connection you have selected.

How To Quickly Check Which SIM Is Used For The Data Connection?

If you want to see what SIM is used for cellular data without passing through all these steps, simply look at the signal strength indicators on the top of the screen. The corresponding indicator of the network used for the Internet connection has a small arrow above it.


As you can see, switching from one SIM to another is a breeze in Windows Phone operating system. Now you know how doing it, all you left to do is to make sure you do not run out of internet traffic. For more tutorials on Windows Phone, check out some of our related articles and if you have any questions or problems, do not hesitate to use the comments form below.