How to set up a choice SIM-Maps for outgoing call on Xiaomi Mi 8: all ways

Xiaomi Mi 8 is one of the most popular flagships of the brand, which is still actively used thanks to powerful hardware and support. MIUI. But the owners of the device with two SIM-The problem with cards is often that when you call them out, the phone automatically selects a SIM without asking the user, which leads to unnecessary costs (if one SIM has unlimited minutes and the other has paid rates) or confusion in work/personal calls.

In this article, we will discuss all possible ways to customize the choice. SIM-Xiaomi Mi 8 cards (including hidden features) MIUI), We'll explain why settings are sometimes reset, and we'll show you how to return a handy SIM before every call. MIUI — From old (9-10) to new (12-14), as well as custom firmware such as Pixel Experience or LineageOS.

If you’re tired of the phone deciding which SIM to call from, or want to split personal and work contacts across different maps, read on. We’ll also look at the unique feature of the Xiaomi Mi 8: when activated, Dual 4G (DSDSDS) mode, some of the SIM settings can be blocked, and show you how to get around it.

Why does Xiaomi Mi 8 not ask which SIM to call?

By default, MIUI is set to be as user-friendly as possible, but it's not always user-friendly.

• 📱 Default setting: In parameters SIM-The card is set as a "main" for calls.
• 🔄 Update MIUI: After upgrading the system settings can be reset (especially when switching from the MIUI 10 to 12.+).
• 📶 Regime. DSDS (Double. 4G): If Settings are enabled → SIM-maps and mobile networks → Double. 4G, part of the function is limited.
• 🛠️ Failure of the communication module: Rarely, but it happens that after a fall or overheating, the phone “forgets” the settings.

The Xiaomi Mi 8 (M1803E1A) also has a bug: if you insert the SIMs of different operators (for example, MTS and Tele2), the system can automatically choose the one that has the best coverage at the moment.

⚠️ Note: If you are using a corporate SIM-card (e.g. from MegaFon Business or Beeline Corporate), some settings may be blocked by the operator's policies.

Method 1: Setting up the selection SIM-maps in standard parameters MIUI

The easiest method is to use built-in settings. It works on all versions of MIUI, but the path to the menu may be slightly different.

Instructions:

1. Open the settings (cog icon on the desktop).
2. Go to section. SIM-maps and mobile networks.
3. Select the Select item SIM-Call cards (or settings) SIM-map → Calls in new versions).
4. Activate the option to always ask (or ask at every call).

If this paragraph is not:

• 🔍 Make sure you have both installed. SIM-cards and they are recognized by the system (the status should not be "No network" or "Error»).
• 📲 Try to reboot your phone – sometimes the settings appear after the reboot.

Both SIM-Cards are active and determined by the phone|

On the menu "SIM-Maps display the names of operators|

Phone is not in "Airplane" mode |

The latest version has been installed MIUI (Check in "Settings" → The phone")-->

Nana MIUI 12.5+ The path may look like this: Settings → Memory and SIM-map → Settings SIM-map → Calls. → If the option is gray and inactive, it means that the mode is on. DSDS (below).

Method 2: Using a quick switch during a call

Even if the settings are “always ask,” sometimes MIUI It ignores this rule, and then you can manually change it. SIM-card right at the time of dialing:

1. Open the phone application and dial the number.
2. Next to the call button will appear double icon SIM-cards (two overlapping cards).
3. Click on this icon and the SIM selection menu will open.
4. Select the desired SIM and press “Call”.

If the badge is not:

• 🔄 Restart the Phone app (close it in multitasking and reopen it).
• 📱 Make sure you don’t have a lightweight version. MIUI (for example, MIUI Lite, where some functions are stripped down.

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If you often call from one SIM to specific numbers (for example, from a work colleague), keep these contacts with a link to the phone. SIM-Open the contact for that. → click "Edit» → choose «SIM-Default card for this contact».

On Xiaomi Mi 8 with Global Stable firmware, this method works consistently, but on China Stable, you sometimes need additional configuration through the engineering menu (about this in method 4).

Method 3: Configure through the engineering menu (for power users)

If the standard methods do not work, you can try to activate the choice. SIM-This is a hidden settings section where you can access low-level parameters of the communication module.

Instructions:

1. Open the Phone app.
2. Enter the combination: ##4636###.
3. Select Phone Information (or Phone Information).
4. Scroll down to the SIM Management block.
5. Click on SIM Slot and select Always Ask (if there is no such option, try other Call-related options).

Warnings:

• 🚨 Do not change other options in the engineering menu – this can lead to loss of the network or failure of the communication module.
• 🔧 If after the changes the phone stopped catching the network, reset the mobile network settings: → SIM-maps and mobile networks → Resetting network settings.

⚠️ Note: On some versions MIUI (for example, MIUI 11 for Xiaomi Mi 8 SE) The engineering menu may be blocked, in which case use method 4 or update the firmware.

Method 4: ADB-commands for forced selection SIM

If none of the previous methods worked, you have to switch the settings over ADB (Android Debug Bridge), which requires connecting the phone to your computer, but gives 100% results.

What you need:

• 💻 Computer with Windows/macOS/Linux.
• 🔌 Cable USB (preferably original).
• 📱 Included debugging by USB on the phone (Settings) → The phone. → Version. MIUI — Press 7 times, then return to Settings → Additionally. → For developers → Debugging by USB).
• 🛠️ Utility. ADB Tools (download and unpack platform-tools).

Step-by-step:

1. Connect Xiaomi Mi 8 to your computer and allow debugging (the phone will be asked).
2. Open the command line (Windows) or terminal (macOS/Linux) in the folder with the platform-tools.
3. Enter the command to check the connection: Adb devices must appear serial number of your device.
4. Execute the command to include the request SIM-Maps: adb shell settings put global multi_sim_voice_call_prompt 1
5. Reboot your phone: adb reboot

After rebooting, a selection window will appear with each outgoing call. SIM-If you want to return the automatic selection, use the same command, but with a 0 instead of 1.

⚠️ Attention: If after completion ADB-team SIM-The card still doesn't work, check if you have a call management app (like Truecaller or Dual App) that can intercept your system settings.

Method 5: Disable the Double 4G (DSDSDS) mode

Xiaomi Mi 8 (and other models with support) DSDS) There's a double function. 4G, which allows both SIM-map 4G However, this mode blocks some settings, including manual selection of the SIM for calls.

How to disable DSDS:

1. Go to Settings. → SIM-maps and mobile networks.
2. Click on Double 4G (or 4G+).
3. Switch the slider to the off position.
4. Reboot the phone.

After the shutdown:

• ✅ The option to always ask in the settings will be available. SIM-map.
• ⚠️ One of them SIM-The map will work in 3G (if both support 4G).
• 📶 Possible deterioration of the Internet speed on the second simka (depends on the operator).

If you’re critically interested in having both SIMs work in 4G, but you need a manual choice – use Method 4 (ADB), it bypasses that limitation.

Yeah, both SIMs in 4G|.

No, I turned it off for manual selection.|

I don't know what it is.|

I have one. SIM-map-->

Problem Solving: What to do if the settings are not saved?

Sometimes users are faced with the fact that after setting up the choice SIM-The cards are being reset:

If nothing helps:

1. Backup important data.
2. Perform a reset of network settings: Settings → SIM-maps and mobile networks → Resetting network settings.
3. If the problem remains, reset your phone to factory settings (Settings → About Phone → Resetting).

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Before resetting, make sure to check if your contacts are saved to your Google or Mi Cloud account. SIM-The card or phone memory will be deleted!

FAQ: Frequent questions about setting up SIM-maps on Xiaomi Mi 8