How to block unfamiliar numbers on Xiaomi: the complete guide

Every smartphone owner faces the problem of intrusive calls from advertising agents or scammers. In the Xiaomi and MIUI ecosystem, this problem is solved at the system level, without the need to install third-party applications. The number lock on these devices is implemented deep in the firmware, which ensures stable operation even after a reboot.

Users often look for complex ways to install bulky programs from the store, while the necessary functionality is already built into the “caller.” Xiaomi’s system blocker works more efficiently than most analogues, since it has access to a database at the kernel level, and in this article we will discuss all available methods of protection against spam, from simple settings to advanced scenarios.

We should not ignore incoming calls from unknown codes, as this may be important. However, if calls are massive and annoying, we need to take action. We will consider how to set up a blacklist so that you don't miss an important call from the courier, but cut off all the garbage.

Built-in protection features in MIUI

The MIUI operating shell and its successor HyperOS have powerful built-in traffic filtering tools, the core element being the Security app, which is pre-installed on every device in the brand, which manages antispam and configures rules for incoming connections.

You don't have to be a tech person to activate the protection, it's as simple as possible and it's adapted for the mass user, you just have to open a standard call app and go to the settings to find the partition you want, and it allows you to flexibly adjust responses to different types of numbers, including hidden and international numbers.

⚠️ Note: After the firmware update, the locker settings may reset to factory values. It is recommended to check the protection status manually after each major system update.

It is important to note that the functionality may vary slightly depending on the shell version and the firmware region (Global, China, EEA).However, the basic logic of calling filtering remains the same in all versions. If you do not find a point, try updating the Security app through the built-in GetApps store.

Setting up a blacklist through the "Security" app

The central node of the ban control is the system utility "Security." It's all the necessary switches. To start setting up, open the app and find an icon with a shield or lightning, which is usually located at the bottom of the screen or in the tool grid.

In the menu that opens, you select "Black List" (or "Block"). This is where you create a list of prohibited contacts and rules. By clicking on the gear icon in the corner of the screen, you will be taken to the settings menu, where you can activate smart lock and configure exceptions.

• 📱 Click on the gear icon in the upper right corner of the blocker screen.
• 🚫 Select the option "Block Unknown Numbers" for complete isolation from strangers.
• ✅ Activate the Antispam switch to use cloud databases.
• 📞 Add specific numbers manually through the Add button in the blacklist menu.

The same menu also includes a keyword blocking feature in SMS, which is especially true for those who receive advertising messages from banks or stores, and you can add the words “credit”, “promotion” or “winning” to the list of stop words, and such messages will be automatically deleted or hidden.

Blocking directly in the "Phone" application

There's a faster way to add a specific number to an ignorant list without going into the deep settings menus. This is ideal when you need to urgently block the person who just called. Open the standard Phone app and go to the call history tab.

Find the number you want to block in the list, click on it to open, or use a long press (context menu). In the action list that appears, select "Block"; the number will instantly disappear from the active zone and be blacklisted.

If you want to block a number that is not in history but is known to you, you can use manual input. From the blacklist menu (as discussed above), select Add Number and enter data manually. There is also a prefix lock option available, which allows you to cut out entire ranges of numbers, for example, from a specific operator or region.

For owners of older versions of MIUI, the path may be slightly different: Phone → Settings → Inbound Lock → Blacklist. In newer versions of the interface, logic is simplified, and management is available directly from a contact card or call log, which makes the process of protecting against spam intuitive.

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Use Quiet Mode for unknown numbers if you are afraid to miss an important call. The call will pass, but the phone will not ring and the subscriber will hear the signal is busy.

Use of the "Do Not Disturb" mode

Do Not Disturb (DND) is often confused with a blacklist, but it's much more powerful, allowing you to create temporary silence profiles by blocking all incoming contacts except your favorite ones, ideal for nighttime or important meetings where you can't be distracted.

Unlike hard locking, DND can skip repeat calls from a single number for a short time. This is emergency insurance. You can configure this mode through the notification curtain or under Settings → Sound and vibration → Do not disturb.

You can schedule your phone to automatically go to silent at night, and you can also set exceptions: you can only allow calls to your favorites or all contacts in the phone book, completely ignoring unknown numbers.

Third-party filtering applications

While Xiaomi’s built-in tools are quite effective, sometimes more specialized solutions are needed: Third-party apps like Truecaller or GetContact have huge user bases that are updated in real time, and can identify numbers that have not yet been included in official spam databases.

But installing these apps requires broad permissions, they get access to your phone book and call history for analysis, which calls into question data privacy, and before you install them, weigh the risks: Are you willing to trade peace for the transfer of contacts to third parties?

If you do decide to install a third-party blocker, set it up correctly. In MIUI, you need to give the application auto-run and permission to work in the background, otherwise the system will “kill” the blocker process to save energy, and spam will break again.

Frequent problems and their solution

Sometimes users are faced with a situation where the configured lock stops working, most often due to the aggressive battery saving policy of the Android system on board Xiaomi, which can force the background services responsible for filtering to stop.

To fix this, look for the Security or Phone app in the app list, click About and select Activity Control. Set No Limits, and it will signal to the system that the process is critical and cannot be interrupted.

Another problem may be syncing blacklist with your Mi Cloud account. If you change your phone, your settings may not automatically change unless you have a backup. Make sure that your Xiaomi account settings tick the sync box for your system applications.

⚠️ Warning: Blocking numbers with a hidden number or an unknown number may result in you being unable to take a call from a doctor, police or emergency services using secure lines.

Also, remember that some messengers (Viber, WhatsApp, Telegram) have their own privacy settings. Locking a number in the Xiaomi phone book does not always block calls through these apps. Check the privacy settings inside each messenger separately.

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System locking on Xiaomi works more stable than third-party analogues, as it does not depend on background processes that can be stopped by the energy saving system.

FAQ: Frequently Asked Questions