Background

In the U.S. and Canada (and possibly other regions), the SIM manager in the Settings app only allows you to select a primary SIM card to be used for calls, texts and data. This limitation isn't present in Samsung devices from other regions. The purpose of this post is to provide a band-aid solution that allows you to set a preferred SIM card for calls, texts, and data individually. I tested this on an unlocked Canadian S23 Ultra and an unlocked U.S. Fold5 review unit provided by Samsung.

Requirements

• Samsung device that supports dual SIM via physical SIM and eSIM (some devices in the U.S. also support dual physical SIMs so this might work for you as well)
• Both SIMs should be enabled and provisioned
• An activity launcher app or ADB

Steps

To choose your preferred SIM card for data, you have to use the built-in SIM manager in the Settings app (Settings -> SIM manager -> Primary SIM). For calls and texts, see below.

Instructions using an activity launcher app such as Activity Launcher:

1. Open the Activity Launcher app
2. Search the following: com.android.settings/com.android.settings.Settings$MobileNetworkListActivity

There should be one entry under Settings labelled "Mobile networks" with a subtitle labelled "com.android.settings/com.android.settings.Settings$MobileNetworkListActivity"

3. Select that entry to launch the activity. This will launch a hidden menu within the Settings app to allow you to configure your preferred SIM for calling and texting.
4. Select your desired SIM card, and it will open a sub-menu containing various settings for that SIM card. From here, you can select "Calls preference" to choose your preferred SIM card for calling, and "SMS preference" to choose your preferred SIM card for texting.
5. If you plan on making these changes often, consider adding a shortcut of this hidden menu to your homescreen (the three dot menu next to the entry in the Activity Launcher app expands to allow you to create a shortcut).

Instructions using ADB

1. Clear the Settings app from your recent apps
2. Run the following command: adb shell am start -n 'com.android.settings/com.android.settings.Settings$MobileNetworkListActivity'

This will launch a hidden menu within the Settings app to allow you to configure your preferred SIM for calling and texting.

3. Select your desired SIM card, and it will open a sub-menu containing various settings for that SIM card. From here, you can select "Calls preference" to choose your preferred SIM card for calling, and "SMS preference" to choose your preferred SIM card for texting.

Instructions if you're lazy

1. Download and open the Samsung Band Selection app.
2. Select "MORE NETWORK SETTINGS"

This will launch a hidden menu within the Settings app to allow you to configure your preferred SIM for calling and texting.

3. Select your desired SIM card, and it will open a sub-menu containing various settings for that SIM card. From here, you can select "Calls preference" to choose your preferred SIM card for calling, and "SMS preference" to choose your preferred SIM card for texting.