How to set a Dual SIM smartphone with Android (default SIM for calls, SMS, data, etc)
Most Dual SIM smartphones use a Dual SIM Dual Standby implementation, that is cheaper to manufacture. This means that, when you insert two SIM cards into your Android smartphone and use the default settings without changing them, the smartphone will use SIM 1 for calls, text messages, data connections, and for making Bluetooth calls. However, you can choose a primary SIM card for each type of activity. Here is how it is done:
NOTE: Android is available in many versions and customizations. To help as many users as possible, we used two different Dual SIM smartphones for this guide: ASUS ZenFone 4 and Huawei P10 lite. Both have Android 7 Nougat installed. If you do not know which version of Android you have on your smartphone, read this tutorial: What version of Android do I have? 3 ways of checking!.
First, access Android's Dual SIM card settings
Open the Settings of your Android smartphone. Then, in the Wireless & networks section, look for "Dual SIM card settings" or "Dual SIM management" and tap on this entry.
You are shown the two SIM cards on your smartphones and their status. First, you see the name of each SIM. Scroll down to the "Preferred SIM card" section or to the area where you have settings about the default SIM card.
On Android smartphones, you can set the preferred SIM for these actions:
- Voice call - you can set the default SIM card for the phone calls that you make on your smartphone.
- SMS messages - you can use only one SIM for sending SMS messages of your own.
- Data service network - you can have only one active data connection to the internet. You must set the preferred SIM for connecting to the internet.
- Preferred Bluetooth call settings - if you use a Bluetooth headset and you make calls using it, you should set the preferred SIM for doing that.
Please keep in mind the fact that the settings that you can change vary based on the Dual SIM implementation used by the manufacturer of your smartphone.
How to set the default SIM for voice calls, in Android
In the screen with Dual SIM settings, look for an entry that is named Voice call or Default calling SIM, and tap on it. Then, choose the SIM card that you want to use as the default. This may be the SIM from the mobile provider with the best plan for phone calls. If you don't want to use one SIM as the default, and you prefer to switch between the two, choose "Always ask" or "Not set."
If you do that, Android always asks you to choose the SIM from which you want to initiate a phone call.
How to set the default SIM for SMS text messages
In the screen with Dual SIM settings, look for an entry that is named SMS messages or Default calling SIM (if there is no individual entry for SMS messages), and tap on it.
Then, choose the SIM card that you want to use as the default. This may be the SIM from the mobile provider with the best plan for text messages.
Some Dual SIM implementations use the same SIM as the default for both voice calls and text messages, while others allow different SIM cards to be used for both tasks. This varies from smartphone to smartphone.
How to set the default SIM for mobile data connections
In the screen with Dual SIM settings, look for an entry that is named Data service network or Default mobile data, and tap on it.
Then, choose the SIM card that you want to use as the default for mobile internet connections on your Android smartphone.
How to set the default SIM for Bluetooth calls
Some Android smartphones like the ASUS ZenFone 4 offer the possibility of choosing the default SIM card for calls that you make using a Bluetooth headset. In the screen with Dual SIM settings, look for an entry that is named Preferred Bluetooth call settings, and tap on it. Then, choose the SIM that you want to use for this activity.
Did this guide help you?
In the world of Android smartphones, there are many different Dual SIM implementations. To make things more difficult, there are also many Android versions and customizations made by manufacturers. We hope that this guide has managed to help you, no matter which smartphone you are using. If it did not, let us know what smartphone you have (the exact model) and what did not work for you. Comment below and let's discuss.