How to permanently block calls from unknown numbers on Xiaomi: the complete guide

Xiaomi smartphone owners face intrusive calls from scammers, spammers and collectors every day. According to statistics, 37% of subscribers in Russia receive at least one unwanted call a week, and one in five faces attempts at phone fraud. MIUI-based smartphones (including Redmi, POCO and Black Shark) offer several built-in protection mechanisms, but most users do not use them, either because of ignorance or because of difficulties with setting up.

In this article, we will analyze all available ways to block unknown numbers on Xiaomi – from basic firmware functions to advanced solutions using third-party applications and operator services. You will learn how to filter out spam before the first beep, set up a blacklist for specific regions, and why the standard Do Not Disturb mode often works worse than specialized blockers. MIUI 14/15, which blocks numbers with a switched caller ID (So often scammers act, masquerading as banks).

1. Built-in lock in MIUI: setting up the "Blacklist"

Firmware MIUI (Since version 12, it includes the basic call filtering tool, the Blacklist, which has the advantage of operating at the system level, which saves battery life and does not require the installation of additional applications. It does not block numbers with a changed identifier (for example, when a fraudster calls allegedly on behalf of Sberbank), nor does it filter. SMS-spam.

To add a number to the blacklist:

1. Open the phone application (pipe icon).
2. Go to the Recent section and find the unwanted number.
3. Click on contact → select Block → Confirm action.

For mass blocking of unknown numbers:

• 🔍 Go to Settings. → Annexes → Phone. → Number locking.
• 📵 Activate the option to Block Unknown Numbers (includes call filtering without ID).
• 🔄 Enable Regular Expression Lock for numbers with the same prefix (e.g., all calls from the same prefix) +7999*).

⚠️ Attention: B MIUI 14 and later, the function of blocking unknown numbers is disabled by default due to conflicts with the operator services. After activation, check if important calls (for example, from delivery services) have stopped passing).

2.Do Not Disturb Mode: Finely customized exceptions

Xiaomi’s Do Not Disturb (DND) feature is often perceived as a tool for silence while sleeping, but it can be adapted to block spam. Unlike the Blacklist, DND allows you to flexibly customize rules for different types of calls – for example, skipping only contacts from the address book or allowing repeated calls from one number for 15 minutes (useful for taxi services).

How to set up:

1. Go to Settings → Sound and vibration → Do not disturb.
2. Select a schedule (for example, around the clock or during working hours).
3. In the Calls section, set up: 📞 Allow calls from → Only contacts. 🔄 Repeated calls → Allow (if one number calls twice in 3 minutes, the call will pass).

The main disadvantage of this method is the lack of flexibility: you either block all unknown numbers or you don't. Third-party applications will be required to filter more accurately.

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If SMS from banks stopped coming after activation of DND, add their numbers to Priority Contacts in the mode settings.

3. Third-party apps: top-3 blocker

The built-in MIUI tools handle basic spam, but to protect against advanced scammers (like callinger ID swaps), it’s better to use specialized applications: they analyze spammer databases, check numbers in real time, and often update filters. Below are three proven solutions optimized for Xiaomi:

• 🛡️ Truecaller – Detects 90% of spam numbers, integrates with the phone and SMS. Requires registration and access to contacts.
• 🔍 GetContact - shows the username of the caller (useful for identifying collectors.
• 📵 CallApp not only blocks calls, but also SMS-There's a cloud blacklist feature that synchronizes devices.

How to set up Truecaller on Xiaomi:

1. Download the app from Google Play.
2. Register through your phone number or Google account.
3. In the settings, turn on: 🔄 Auto-blocking spam. 📞 Replacement of the standard phone application (optional). 🔍 Showing the names of strangers.

⚠️ Note: Apps like Truecaller collect your contacts to build a database. If it's critical for you, use CallApp in non-registration mode (functionality will be limited).

Make sure the app has >1M downloads in Google Play|

Read the reviews of the latest update |

Check permissions (no geolocation or file access) |

Create a backup copy of your contacts-->

4. Blocking at the operator level: services from MTS, Beeline, MegaFon

Russian operators offer their own spam filtering solutions that work before a call hits your smartphone, which reduces battery load and guarantees lock-down even when the phone is turned off, but these services are often paid (from 30 to 100 rubles per month) and can conflict with the built-in MIUI features.

Advantages of operator services:

• 🔄 Work even when resetting the phone to factory settings.
• 📡 Filter SMS-Spam (unlike most other applications).
• 🛡️ Block numbers with a substitute caller ID network-level.

Disadvantages:

• 💰 Paid fares (except MTS and Tele2).
• 📵 Can block legitimate calls (for example, from new customers if you are a freelancer).
• 🔧 No flexible settings (you can not add a number to the exceptions).

5. Hidden MIUI function: blocking regions and prefixes

Few people know, but MIUI 14/15 has a hidden tool to block calls by geographical indication, such as disallowing all calls from numbers starting at +375 (Belarus) or +994 (Azerbaijan), where scammers often call, which has no graphical interface and is configured via an engineer mode.

Instructions for advanced users:

1. Open the Phone app and dial ##4636##.
2. Go to Phone Information → Menu → Call settings.
3. Find the Blocking section by prefix (could be called Call Barring).
4. Add the number masks through the comma, for example: +375, +994, +995, +93, +92
5. Save the settings and restart the phone.

⚠️ Attention: Incorrect settings in the engineering menu may disrupt the communication module. If the network is lost after the changes, reset the settings via ##4636## → "Reset" → "Radio Band".

This feature is particularly useful for blocking:

• 🌍 International spammers (numbers from +1, +234, +27.).
• 📞 Fraudsters masquerading as banks (numbers with prefixes) +7495, +7800).
• 🔢 Auto dialers from collectors (often use virtual numbers with the same beginning).

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Prefix blocking is the only way to cut off calls with a swapped caller ID that are not filtered by standard methods.

Additional measures: two-factor authentication and backup

Even with the unknown number lock enabled, the risk of missing an important call remains. To minimize the consequences, configure:

• 🔐 Two-factor authentication (2FA) This will protect you even if a scammer gets access to your number.
• ☁️ Backup of the blacklist. MIUI Export it through Settings → Annexes → Phone. → Number locking → Exports.
• 📱 Duplicate important contacts to the cloud (Google Contacts or Mi Cloud) and when you reset your phone, they will automatically recover.

How to Enable 2FA for Mi Account (Xiaomi Account):

1. Go to Settings → Xiaomi Account → Security.
2. Choose a two-step check.
3. Attach your phone number or email to recover.
4. Save your backup codes in a safe place (e.g. Google Keep).

If you frequently encounter hacking attempts (e.g., through the SMS With a confirmation code, install an Authy or Google Authenticator app to generate one-time passwords. SMS scammer.

7. Frequent mistakes and how to avoid them

Many Xiaomi users have problems with locking unknown numbers, and here are the most common errors and solutions:

• 📵 No important calls (from doctor, courier): Check if Do Not Disturb in the background is on. Add exceptions for repeat calls (Settings) → Sound. → Don't disturb. → Repeated calls).
• 🔄 Spam continues to pass: Update the database in the blocker app (in Truecaller: Settings) → Update the database. Check if the contact sync is off.
• 📱 Fast battery discharge after locker installation: Turn off background activity for the app (Settings) → Annexes → Battery management → Select the application → No restrictions).
• 🔍 Numbers are blocked, but notifications arrive: In Phone settings, turn off the Blocked Call Log (Settings) → Number locking → Notifications).

If after all the settings spam calls continue to arrive, check:

• 📡 Network signal (fraudulents often call when coverage is weak when backup channels are triggered).
• 🔄 Firmware updates (Settings) → The phone. → Updating the system).
• 🛡️ Viruses (scan your phone through Malwarebytes).

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If the blocker stopped working after the MIUI update, clear the Phone app cache (Settings → Apps → Phone → Clear the cache).

FAQ: Answers to Frequent Questions