Mask locking on Xiaomi: the complete guide to MIUI 14/15

Spam calls from numbers disguised as banks, government services or well-known companies have become a real attack for smartphone owners. Xiaomi with the MIUI shell has built-in tools to combat them, but masked locking numbers (such as +79123 or 8800*) requires knowledge of hidden functions. Unlike locking a specific number, template filtering allows you to automatically screen out entire groups of fraudulent calls - but not all users know how to configure this correctly.

In this article, we will break down the unique mask blocking methods on Xiaomi, including little-known features. MIUI, You will learn how to work with the built-in blocker, which third-party applications are really effective, and why some masks (such as those with the # symbol) may not be blocked by standard means. Special attention is paid to the nuances for the latest versions MIUI 14 and MIUI 15, where the lock interface has changed.

What is a mask lock and why you need it

The number mask lock is a filtering of incoming calls and SMS by pattern, not by exact match. For example, the +7903* mask will block all numbers starting with +7903, and *123# - all calls ending with 123# (the kind often used by fraudsters to simulate service numbers).

This feature is especially relevant on Xiaomi for three reasons:

• 📞 Fraudulent schemes: Attackers often use dynamic numbers with the same prefix (e.g, +7999123*) The mask lock allows them all to be cut off at once.
• 📊 Spam from operators: Many mobile operators send ads from the number 8800* or 900*. the Mask blocks them all without affecting important notifications.
• 🔍 Hidden numbers: B MIUI You can even block calls with a changed caller. ID (For example, the Bank or public services, if they correspond to a given template.

It's important to understand that mask locking doesn't replace the standard blacklist, it complements it. For example, if you add +79123456789 to the blacklist and then create a mask of +7912*, the first number will be blocked twice - but it will not affect performance.

MIUI Integrated Mask Locking Tools

In MIUI 14/15, the mask lock function is hidden in the phone app settings to find it:

1. Open the phone application (pipe icon).
2. Slip on three dots in the upper right corner → select Settings.
3. Go to the section "Number Lock" (or "Spam and Lock" on some models).
4. Select Add Mask (may be called a template filter).

Here you can enter the mask manually. The following symbols are supported:

⚠️ Note: On some firmware (especially global) the symbol! for exceptions does not work.

Enter the mask in +79*** format (for Russian numbers)

Make sure there are no extra gaps or dashes

Check the mask on your friend's number (temporarily add it to the exceptions)

Save the mask and restart the phone (sometimes required for use)-->

Hidden MIUI settings for advanced filtering

If standard masks do not help (for example, do not block numbers with a changed caller ID), you can use hidden MIUI codes.

Open the Phone app and enter the following combinations:

• 🔢 ##64663## → MTK Engineer Mode → Telephony → Call Blocking (for devices running MediaTek processors).

⚠️ Note: Use of the Engineering Menu (MTK Engineer Mode can cause a communication module to malfunction. Don't change settings unless you're sure they're there. For example, a bad Band Selection setup can take your network out of your hands.

For devices on Qualcomm Snapdragon (most flagships Xiaomi) available alternative method:

adb shell settings put global block_unknown_callers 1


adb shell settings put global block_private_callers 1

These commands block all hidden and unknown numbers. To unlock the lock, replace 1 with 0.

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If nothing happens after you enter the code, try using the Google Play Activity Launcher app, which allows you to run hidden system menus without codes.

Third-party applications for mask blocking

If the built-in MIUI tools don't work (for example, they don't block numbers with a changed name), you can install specialized applications.

For maximum efficiency, it is recommended to combine Truecaller (to identify the caller ID) and Call Blocker (for flexible masks).

1. In Truecaller, set up a lock on all numbers marked as “Spam” or “Cracker”.
2. In Call Blocker, add masks for operator numbers (e.g. 8800* or +7900*).

⚠️ Note: Some applications (such as Truecaller) may conflict with the built-in blocker. MIUI. If after installation, numbers from the standard blacklist cease to be blocked, disable duplicate functions in the application settings.

Why masks may not work and how to fix them

A common problem is that the user added a mask (e.g. +7903*), but calls from these numbers still pass.

• 🔢 Wrong Mask Formatting: MIUI It's format sensitive. For example, 8903 and +7903 are different masks. Always use the full international format (+7...).
• 🛠️ System service failure: Enter the phone code ##4636##, select Phone Information and click Run the ping test. If the test fails, restart the device.

If the problem persists, check if the lock is disabled in the power saving mode:

1. Go to Settings → Battery and Performance → Energy Saving Mode.
2. Click Mode Settings → Background Limits.
3. Make sure that the phone application is not limited.

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On some firmware (e.g. MIUI Global for Europe), mask locking is disabled at firmware level, in which case only MIUI China firmware or third-party applications will help.

Blocking masks in SMS and messengers

The built-in MIUI blocker can filter not only calls, but also SMS.

1. Open the Messages app.
2. Tap three points. → Settings → Blocking and spam.
3. Enable the option to block messages from unknowns.
4. Add masks to the Blacklist section (similar to blocking calls).

For messengers (WhatsApp, Telegram, Viber) blocking mask works differently:

• 💬 WhatsApp: It doesn't support masks, it only supports exact numbers. You can use bots like this. @SpamBlockBot.
• 📧 Telegram: In the privacy settings there is an option Who can write to me → My contacts (blocking everyone else).
• 🎧 Viber: Supports locking by prefix in Settings → Confidentiality → Blacklist. → Add the template.

⚠️ Note: Telegram does not block "unknown" channels and bots. Fraudsters often use bots with names of the species @Bank_Support_Bot — They need to be locked manually.

Backup and transfer masks to the new Xiaomi

If you change your smartphone or reset your settings, save the block list:

1. For the built-in MIUI blocker: Open Settings → Google → Backup. Make sure App Settings are backed up. After reset, restore your Google account data.

Call Blocker

• Export the rules to a file (usually in.csv or.json format).
• Save the file to Mi Cloud or Google Drive.

If you use Truecaller, log in to it on a new device – all locks are synchronized automatically through your account.

⚠️ Warning: When you transfer masks from one device to another, consider the difference in firmware. +79* can be used for MIUI China, but ignored by the MIUI Global due to different blocking policies.

FAQ: Frequent questions about mask blocking on Xiaomi