How to permanently block unknown incoming calls to Xiaomi: from standard tools to secret MIUI chips

Unknown calls from scammers, spammers and intrusive marketers became an epidemic in 2026. Smartphone owners Xiaomi, Redmi and POCO face this problem every day: according to statistics, 47% of subscribers receive at least one suspicious call a week. But unlike iPhone or naked Android, MIUI firmware offers unique tools to combat spam – from built-in Call Blocker to hidden features based on artificial intelligence.

In this article, we will discuss 5 proven ways to block unknown numbers, from basic settings to advanced tricks that are not even told in the official documentation.

• 📵 Set up automatic locking of all numbers without contact in the phone book
• 🤖 Use an AI filter MIUI Recognition of fraudulent calls in real time
• 📱 Create a whitelist of trusted contacts bypassing all restrictions
• 🛡️ Install third-party applications that work better than standard tools
• 🔍 Track and block numbers through Call Log with call analytics

Important: The methods work on all current versions of MIUI 14/15 (including HyperOS for new models) and are compatible with devices from Xiaomi 11T to POCO F6. If you have older firmware (MIUI 12 and below), some features may be missing - check availability in the settings.

1. Standard lock through MIUI Blacklist

The easiest way to do this is to use the built-in Call Blocker tool that every Xiaomi smartphone has, which lets you add numbers manually or block entire categories of calls (like hidden numbers).

1. Open the Phone app (the tube icon on the home screen).
2. Slip on the three dots in the upper right corner → select Settings.
3. Go to the section Blocker and spam filter (on some models – Block numbers).
4. Activate the call blocker switch.
5. Select Blacklist → Click Add and enter the number manually or select from the log.

🔹 Feature MIUI: Here you can block not only specific numbers, but also entire prefixes (for example, all numbers starting on the Internet). +375 to block Belarusian spammers. To do this, when adding a number to the blacklist, select the option Add to the template.

Added number to call log?|Is the blocker activated in the settings?|Are there any important contacts on the blacklist?|Is the phone app updated to the latest version?-->

⚠️ Warning: If calls continue to arrive after blocking, check if the blocker is disabled in Settings → Annexes → Permits → Autostart: Some battery optimizers (e.g., Lean) can shut down background processes, including call filtering.

2. Automatic locking of all unknown numbers

If you're sick of calling from unfamiliar numbers (like bank scams or taxi services), MIUI has Unknown Blocking, which cuts off all incoming numbers from numbers that aren't in your phone book, a radical but effective method.

How to turn on:

1. Start Phone → Settings → Blocker and spam filter.
2. Activate the option to Block Unknown Numbers (or Unknown Filter on new versions).
3. In the window that appears, confirm the action - now all calls from numbers that are not in the contacts will be automatically reset.

💡 Secret Lifehack: If you are afraid to miss an important call, but want to block unknown numbers, create a contact with the name in the phone book!! Then, in the Blocker settings, select Allow Calls Only from Contacts and exclude this contact from the rules.

Daily | Several times a week | Rare but apt |Never-->

Xiaomi’s AI Spam Filter: How to Enable and Configure

Starting with MIUI 13, Xiaomi has integrated an artificial intelligence system into firmware to analyze incoming calls, which compares numbers to a database of spammers (updated daily) and automatically blocks suspicious calls, a feature called Spam Filter and works on a machine learning basis.

To activate it:

1. Open the phone → Settings → Blocker and spam filter.
2. Turn on the Spam Filter (or Spam Protection on HyperOS) switch.
3. Select the filter settings and select the level of aggression: 🛡️ Medium – only blocks obvious spam (recommended) 🔒 High – blocks all suspicious numbers (may falsely trigger) 📱 Low - only obvious fraudsters (ineffectively)

Show notifications about blocked calls

⚠️ Note: The AI filter only works when connected to the Internet, as it checks numbers on Xiaomi’s cloud database. If you have mobile data or Wi-Fi disabled, the filtering efficiency drops to 30%.

4.Third-party applications for blocking calls: TOP-3 for Xiaomi

If standard MIUI tools fail, you can install specialized applications, which offer advanced features: voice spam recognition, geolocation lock, integration with instant messengers, and even retaliation for scammers (sending an SMS with a warning).

🔹 If you want maximum protection, install Truecaller. Hiya is better for dealing with bank fraud, and if privacy is important, Should I Answer).

💡

Before installing a third-party blocker, turn off the built-in spam filter in MIUI to avoid conflicts. Go to Settings → Applications → Application Management → Phone → Permissions and reset permission to Read Call Logs for third-party software.

5. Hidden MIUI settings: lock through engineering menu

Few people know, but MIUI has a hidden Engineering Mode that can configure additional call lock options, a technique that is suitable for advanced users, such as blocking IMEI calls or setting timeouts for incoming calls.

Instructions:

1. Open the phone app and enter the code: ##4636##
2. In the menu that appears, select Phone Information (or Phone Information).
3. Scroll down to the Set preferred network type section – you can limit the types of calls (for example, block VoLTE calls, which are often used by scammers).
4. To block IMEI, go to Settings → About Phone → General Information → IMEI Status and blacklist unwanted identifiers via ##4636## → DSDS Information.

Method 2: Through the Truecaller app

1. Install and open Truecaller.
2. Go to Settings → Lock → Lock hidden numbers.
3. Turn on the switch and confirm the action.

🔹 Why do operators not block hidden numbers by default? The point is in the legislation: in Russia and CIS countries, hiding a number is allowed for certain categories of subscribers (for example, security services or hotlines.

7. How to unlock the number if you are wrong

If you accidentally blacklist an important number or turn on too aggressive filtering, here’s how to get your calls back:

For the standard MIUI blacklist:

1. Open Phone → Settings → Blocker and spam filter → Blacklist.
2. Find the number in the list and swipe it to the left (or tap it on the basket).
3. Confirm removal.

For the AI filter:

1. Go to the phone → magazine → Blocked.
2. Select a number. → Unlock.
3. Add it to your contacts to avoid being blocked again.

If the number is blocked through the engineering menu:

1. Enter the code ##4636##.
2. Move to the DSDS Information → Blacklist.
3. Remove the number or IMEI from the list.

💡

After unlocking the number, restart the phone – this will reset the cache of the telephony module and ensure the application of changes.

FAQ: Frequent questions about blocking calls on Xiaomi