Blocking Unknown Numbers on Xiaomi: A Complete 2026 Guide

Every Xiaomi smartphone owner will eventually face intrusive calls from unknown numbers: Scammers, spam emails from banks, aggressive marketers all use phone calls as a tool of influence. According to Kaspersky statistics for 2023, 68% of smartphone users in Russia received at least one unwanted call a week, especially vulnerable owners of low-end models Redmi and POCO, where standard security settings are often disabled by default.

In this article, we will analyze all available ways to block unknown numbers on Xiaomi devices – from built-in functions. MIUI You will learn how to set up a blacklist, use operator filters, and why the standard Do Not Disturb mode does not always save you from spam. MIUI 12 to HyperOS and smartphone models.

Why Xiaomi’s standard lockout doesn’t work

Many users complain that even after adding a number to the blacklist, calls continue to arrive, the reason lies in the peculiarities of the Android phone stack and Xiaomi's policy:

• 📱 Limitations MIUI: In firmware before MIUI 14 The lock only worked for contacts from the phone book, and the numbers that were not stored in the device's memory were ignored.
• 🔄 VoIP bypass: Modern spammers use Internet telephony (for example, via WhatsApp Calls or Skype) that standard filters do not recognize.
• 📡 Operator problems: Some mobile operators (e.g. Tele2) do not transmit caller data, which makes it impossible for the system to identify the number as “unknown".

Another common problem is resetting the blacklist settings after a firmware update, which is because Xiaomi stores the lock data in the system partition, which is overwritten when it updates, so the solution is to use cloud backup or third-party apps.

Method 1: Built-in blacklist in MIUI

The easiest method is to use the standard locking functionality available on all Xiaomi smartphones, the instructions are relevant for MIUI 12-14 and HyperOS:

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 Block in New Versions”).
4. Click Add to the blacklist and select a number from the magazine or enter manually.

To block all unknown numbers:

1. In the same section, activate the Block Unknown Numbers switch.
2. Select the action: Reject the call or Send to voicemail.

Added all spam numbers from the magazine |Blocking unknowns activated |Configured backup list |Configured work after reboot-->

Important nuance: Some models (like the Redmi Note 11) have hidden the option to lock unknown numbers, so you can activate it by:

1. Go to Settings → Applications → Application Management.
2. Find the phone and give permission to read call logs.
3. Reboot the smartphone.

Method 2: Use of the "Do Not Disturb" mode

The Do Not Disturb (DND) feature in MIUI allows you to flexibly configure incoming call filtering, and unlike the blacklist, you can set time rules and exceptions for important contacts.

How to set up:

1. Go to Settings → Sound and vibration → Do not disturb.
2. Activate the mode and select Rules Setting.
3. In the Calls section, set Contacts Only or Repeat Calls (if someone calls twice within 3 minutes, the signal will sound).
4. Add exceptions for selected contacts in Allow calls from.

In HyperOS (starting with Xiaomi 13 and Redmi K60), Do Not Disturb mode is integrated with Focus Mode, which allows you to automatically enable call filtering during work, sleep or calendar meetings.

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If after activation of "Do not disturb" SMS from banks stopped coming, add short numbers (for example, 900 for Sberbank) in exceptions in the Messages section.

Method 3: Third-party applications for blocking

Built-in MIUI tools don’t always work with modern spam techniques, and for advanced protection, we recommend using specialized applications:

• 🛡️ Truecaller — databases with over 300 million spam numbers, real-time identification of fraudsters.
• 🚫 CallApp - locking by geolocation (for example, you can ban calls from other countries), recording conversations. Supports the Russian-language interface.
• 🔍 Hiya -- analyzes caller behavior and blocks suspicious numbers to the first beep.
• 📊 Should I Answer? - Open source, no ads, user-updated databases. Perfect for privacy paranoids.

How to install and configure (as an example of Truecaller):

1. Download the app from Google Play (avoid APKs from third-party sites!).
2. Register through your phone number or Google account.
3. In settings, enable: Spam Block → Automatic Call Identification → Show the name of the caller Cloud Backup (to avoid losing the blacklist)

Blacklist.

⚠️ Note: Apps like Truecaller collect data about your contacts and calls to improve your databases. If critical, use Should I Answer? with your sync turned off.

Method 4: Filtering at the operator level

Mobile operators provide their own services to block spam, and their advantage is that filtering occurs at the network level before a call reaches your smartphone, which saves battery life and traffic.

The effectiveness of operator filters varies:

MTS and Beeline block up to 80% of spam due to integration with the Roskomnadzor database.

Tele2 often misses calls with switched numbers (spoofing).

MegaFon requires a paid subscription, but offers advanced call analytics.

To check if the filter is working, call from another phone to your number with a changed ID (for example, via Skype).

Method 5: Blocking through settings SIM-map

Little-known method – adjusting the filtering directly in parameters SIM-This works on all Xiaomi smartphones, including older models (Redmi). 4X, Mi A1):

1. Go to Settings. → SIM-maps and mobile networks.
2. Choose yours. SIM-card (if there are several).
3. Select the additional settings (or call settings).
4. Find the Deflection or Auto Deflection item.
5. Activate the option and add numbers manually or select All incoming (for full lock).

On some firmware (e.g. MIUI 11), this section may be called Call Filter. If you don't have an option, update your firmware or use the USSD code:

• For activation: 35[number]# (e.g. *35*1234567#)
• For deactivation: #35*[number]#
• To check status: *#35#

⚠️ Attention: Setup through SIM-The card may conflict with the built-in blacklist MIUI. If the calls are no longer blocked, disable one of the methods.

Additional protection measures

Even with the lock on, spammers can seep through loopholes.

• 🔗 Redirect to non-existent number: Set up a redirect of unknown calls to 0000000 (in settings) SIM-map → Call forwarding).
• 📞 Voicemail as a filter: Turn on voicemail from the operator and set a short timeout (5 seconds.
• 🔄 Double. SIM-map: Use one SIM For personal contacts, and the second (with a tariff without subscription fees) for registrations and public purposes.
• 🛠️ ADB-For experienced users: Adb shell can block system alerts for missed calls from unknown numbers: adb shell settings put global block_unknown_callers 1

For owners of smartphones with HyperOS, the Private Mode feature (Settings → Privacy → Private Mode) is available. You can create a separate profile with a unique number for registration in services - all calls to this number will be automatically blocked in the main profile.

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The combination of built-in blacklist + operator filter + Truecaller app blocks up to 95% of spam calls.

Frequent problems and their solutions

Even after you set up the lock, users have a problem, and we'll look at the typical scenarios.

• 📵 Calls pass despite locks: Check if you have added an exception number to the "Do Not Disturb" settings. Update the databases in the blocker app (in Truecaller: Settings) → Update the database. Install Google Phone from Play Market, it has more stringent filtering algorithms.
• 🔄 Reset settings after update: Before updating, export the blacklist to the file (in MIUI: Phone settings → Lockdown → Exports. Use cloud backup (Settings) → Xiaomi account → Backup).
• 📞 Important calls are blocked: Add important number prefixes (e.g, +7800 for banks) in exception. Set up Truecaller category Important for business contacts.

If the problem persists, check your smartphone for viruses using Xiaomi Security (Settings) → Some Trojans (e.g. Joker) replace lock settings.