How to permanently block unknown numbers on Xiaomi: 5 proven ways

Spam calls and messages from unknown numbers became an epidemic in 2026. According to Kaspersky, one in three Xiaomi smartphone owners encounter fraudulent calls at least once a week. Fortunately, the manufacturer has integrated powerful tools into MIUI to combat this, from built-in blacklists to artificial intelligence that analyzes incoming calls.

In this article, we’ll not only break down standard lock methods through Settings → Apps → Phone, but also covert MIUI 14/15 features that aren’t mentioned in the official instructions. You’ll learn how to set up automatic number geolocation filtering, create a whitelist of trusted contacts, and even block entire operator codes. And for owners of older models (Redmi Note 8 Pro, Mi 9T), we’ll give you alternative solutions using third-party apps that don’t eat the battery.

1.A built-in blacklist in MIUI: How it works and why it’s not enough

The basic lock function in Xiaomi is hidden in the phone menu to activate it:

1. Open the phone application
2. Slip on three points in the upper right corner → Settings
3. Select Number Lock → Blacklist
4. Add numbers manually or from the call log

However, this method has critical limitations:

• 🔄 Does not block hidden numbers (where instead of numbers, "Unknown" or "Private" is displayed")
• 📞 Not filtering. SMS — Spam messages will continue to arrive
• 🔢 Limit 500 numbers in the black list (on models with a MIUI below 14 - only 100)
• ⏳ No automatic updates – new spam numbers will have to be added manually

💡

If you have a number number number number number +79xxxxxx888, add a mask +79*888 to the blacklist, which will block all combinations ending in 888.

For owners of POCO F5 and Xiaomi 13 Pro, an extended version of the blacklist with an analysis of the behavior of the caller is available.

• 🕒 Calling outside working hours (from 22:00 to 8:00)
• 📱 They use virtual SIM-Cards (determined by operator signature)
• 🔄 Make less than 3 seconds between calls (typical for robots)

2.Setting up the spam filter in MIUI: hidden opportunities

Few people know, but MIUI 14+ has a built-in spam filter that runs on the Xiaomi Cloud database to activate it:

1. Go to Settings → Applications → Phone → Spam filter
2. Turn on the call filter switch
3. Select the level of aggression: Low – blocks only confirmed spam numbers – adds behavior analysis (recommended) High – can block legitimate calls (for example, from bank call centers)

Block hidden numbers

The thing about this filter is that it learns from reports from users around the world, and if a number is tagged as spam by 50 Xiaomi users, it automatically gets blacklisted globally, and your contacts from the phone book are never blocked.

On Redmi 12s and later, Smart Blocking is available, which analyzes the location of the number, the time of day and the frequency of calls, for example, if you get a call from Nigeria at 3 a.m., the call will be automatically rejected.

3.Whitelist: How to Allow Calls Only From Verified Numbers

If you want to be able to call only contacts from the phone book, set up a whitelist, which is relevant for businessmen, journalists or those who have been the victim of mass spam.

1. Open the phone → Settings → Locking numbers
2. Activate Contact Only Mode
3. In the Exclusions section, add numbers that must pass even without saving to contacts (for example, bank support)

For owners of Xiaomi 14 Ultra, an advanced version of the whitelist with priorities is available, for example, you can configure that calls from family always pass, even if the phone is silent.

Third-party applications: when embedded functions are not enough

If you are using the Redmi 9A or another model with an outdated version of MIUI (below 12.5), the built-in tools may not be able to cope with modern spam.

For installation:

1. Download APK from the official website (not from third-party sources!)
2. Allow installation from unknown sources in Settings → Applications → Special Access → Installation of unknown applications
3. Launch the application and provide access to: 📞 Call log. 📱 Contacts (optional) 📶 SMS (If you need to filter messages)

Download the official version from the site truecaller.com| Disable "Contact recommendations" in the settings |Activate "Blocking by region" (Russia, Ukraine, Kazakhstan) |Configure automatic update of the spam database |Add bank numbers to the whitelist-->

Security Warning: Never install applications to block calls from unverified sources. In 2023, hackers distributed the FluBot Trojan, which steals bank card data, through such utilities. Check permissions: a legitimate application should not request access to: Call management (log read only), SMS (if you do not need to filter messages), Geolocations.

5. Blocking by operator and geolocation codes

If you are flooded with calls from certain codes (for example, +375 for Belarus or +994 for Azerbaijan), you can block whole ranges.

1. Install Call Blocker app (available on Google Play)
2. Go to the Rules section. → Country Codes
3. Select countries/regions to block
4. Block all calls from selected countries

To lock by operator (for example, all Tele2 or Yota numbers):

1. Open Settings → Applications → Phone → Spam filter
2. Select Additional Settings → Blocking by Prefix
3. Add operator codes (e.g. 902, 904 for MegaFon)
4. Advanced Protection (via Google Messages): Install Google Messages from Play Market Activate Spam Protection in Settings Enable Spam Report option to improve database

To block SMS from specific numbers:

1. Open the spam message
2. Tap it on three points. → Details.
3. Choose Block and Confirm

If the problem is firmware, try resetting your phone settings:

1. Go to Settings → About the phone → Reset settings
2. Select Network Settings Reset (this won’t delete your data)
3. After restarting, reset the spam filter.

For the POCO X5 and Redmi Note 12 models with MIUI 14, there is a hidden command to diagnose locking:

Enter the phone in the app: ##2562##


Select "Call Lock Test"




Check status: If it says "Filter: Disabled", the filter is disabled at the system level.

8. Alternative methods: SIM-map

If the software methods do not help, contact your operator. Most Russian providers offer free protection services:

You can also:

• 🔄 Change the number (last resort if your number is in the spammer database)
• 📱 Use the virtual SIM (For example, from Tinkoff Mobile to register on websites
• 🔒 Activate two-factor authentication from the operator so that fraudsters can’t steal your number

💡

Operators block only known spam numbers.New scams can pass, so combine operator protection with phone settings.

On Xiaomi models with eSIM support (for example, Xiaomi 13 Lite), you can set up a separate profile for work, where only corporate numbers will be available, and all other calls will be blocked.

FAQ: Answers to Frequent Questions