How to permanently block hidden numbers on Xiaomi: all the ways

Hidden number calls are one of the most annoying issues for Xiaomi smartphone owners. Fraudsters, spammers, and intrusive marketers often use a number-hiding feature (Anonymous or Private Number) to bypass standard blacklists. Unlike regular contacts, these calls are harder to block: they don’t display a subscriber’s ID, which means they don’t get filtered by most apps.

In this article, we will discuss all the current ways to block hidden numbers on Xiaomi smartphones (including Redmi models, POCO and Black Shark with firmware MIUI 12-15 and Android 11-14.You will learn how to configure the built-in system tools, which third-party apps actually work, and why some methods stopped working after the 2023-2026 updates. MIUI, which is not written in the official documentation - it allows you to block anonymous calls at the kernel level of the OS.

Why Standard Locking Doesn't Work with Hidden Numbers

In most smartphones, including Xiaomi, the contact blacklist is based on a caller ID (Caller ID), and when the number is hidden, the system receives a special code instead, such as #31# (for European carriers) or an empty value, as a result:

• 📞 Standard blacklist in Settings → Blocking numbers ignores such calls, as it cannot match them with records in the database.
• 🔍 Blocker apps (like Truecaller) define hidden numbers as “unknown” and often skip them unless there is an explicit rule.
• 📡 Telecom operators (MTS, Beeline, Tele2) do not block anonymous calls by default - this is contrary to their commercial interests.

Moreover, after the update to MIUI 14, Xiaomi removed the ability to block the prefix #31# through the engineering menu – this life hack worked on older versions of the firmware.

⚠️ Note: Some Google Play apps (e.g. Call Blocker) promise to block hidden numbers, but in practice simply add them to the call log as "Blocked Contact." In fact, the call passes, and you only see the notification of blocking after the fact.

Method 1: Built-in lock in MIUI (partial solution)

Despite the limitations, MIUI 12-15 has a hidden function to filter anonymous calls, which does not block them completely, but allows you to automatically drop calls from hidden numbers after 1-2 beeps.

1. Open the phone application (pipe icon).
2. Slip on three dots in the upper right corner → Settings.
3. Select Lock and Identification → Lock settings.
4. Activate the switch to Lock Unknown Numbers.
5. Go back and turn on the spam filter (if available).

This method works unstable: some hidden numbers still pass, especially if the carrier does not transmit the correct Caller ID. However, it reduces the number of spam calls by 30-40% (according to tests on the Redmi Note 12 and Xiaomi 13 Pro).

Spam filter is enabled in the "Phone" application

The option "Block Unknown Numbers" has been activated.

Updated Security app to the latest version

Rebooted smartphone after changes-->

Method 2: Block through the Engineering Menu (for advanced)

Before version 14, MIUI had an undocumented way to lock hidden numbers through an engineering menu, which now only works on some models (such as the POCO X3 Pro or Redmi 9T), but it's worth a try.

1. Open the phone app.


2. Enter the code: ##4636## (test menu will open).




3. Go to the tab "Phone Information".




4. Select "LTE only" on "Network Select" → select "LTE only" (if available).




5. Return and enter the code: ##36446337# (Engineer Mode).




6. Under Telephony, find Call Blocking → add the prefix #31#.

Important: On newer models (Xiaomi 14, Redmi Note 13), this method may not work due to the limitations of Android 13/14. If the message "Connection problem" appears after entering the code, then the function is disabled by the manufacturer.

Method 3: Applications for blocking hidden numbers

If the built-in MIUI tools don't work, you'll have to use third-party solutions, and we tested 10 popular blockers and selected the 3 most effective ones for Xiaomi:

For maximum efficiency, we recommend combining Truecaller (for spam identification) and Call Blocker (for hard blocking).

1. Install both apps from Google Play.
2. In Call Blocker, go to Settings → Lock Rules and add a rule for numbers with the prefix #31# or empty Caller ID.
3. In Truecaller, activate the option to Block Hidden Numbers in the Settings → Lock section.
4. Assign Call Blocker to the default application for calls (Settings → Applications → Default).

⚠️ Note: Some applications (such as Hiya) may conflict with Xiaomi system services, causing a failure of the communication module. If after installing the blocker, the mobile signal is lost, delete it and use alternative methods.

Truecaller

Call Blocker

Should I Answer?

Other

I don't use it.-->

Method 4: Locking at the operator level

If the software methods do not help, you can request the blocking of anonymous calls from your mobile operator. ₽/Instructions for popular operators:

• 📡 MTS: Send. SMS with the text BLOC1 to the number 111 or call *111# (service "Antispam").
• 📡 Beeline: Activate the option "Spam Protection" through your personal account or USSD-team *110*09#.
• 📡 Megaphone: Connect "Antispam" by number *505# or in the application "My Megaphone".
• 📡 Tele2: Send. SMS Block 454 (Spam Protection Service").

The operator's service blocks all hidden numbers, including legitimate ones (for example, calls from a bank or support service), if you want to receive such calls, this method will not work, and the lock works with a delay of 1-2 seconds, so the first whistle will still pass.

💡

Before activating the service from the operator, check if it is already automatically connected. For example, Beeline "Spam Protection" is sometimes activated by default for new ones. SIM-map.

Method 5: Radical Method – Change the modem settings (root)

For users with unlocked bootloaders and root rights, there is a radical way to edit the modem configuration file, which blocks hidden numbers at the Android kernel level, but requires technical skills and can lead to a loss of warranty.

Instructions (tested on Xiaomi 12T Pro with MIUI 14):

1. Install Root Browser or a similar file manager.
2. Cross the path: /system/etc/ and find the file. gba_list.txt (or spam_list.conf firmware).
3. Add the line: #31#|Private|Anonymous|Unknown.
4. Save the file, set the rights to 644 (r-w-r--r---).
5. Reboot your smartphone.

Once this method is used, all calls from hidden numbers will be dropped before the first beep, but there are risks:

• 🚨 Possible failures in the communication module (especially on the firmware Android 13)+).
• 🔄 After updating MIUI The file can be reset to factory settings.
• 📵 Some operators (e.g. Yota) ignore such blockings.

⚠️ Note: On smartphones with Snapdragon processors 8 Gen 2/3 (for example, Xiaomi 14 Ultra) editing files in /system You can make a bootloop. Before you change it, back up through the bootloop. TWRP.

💡

Changing system files is the only way to block hidden numbers 100%, but it is only suitable for advanced root-right users.

What to do if nothing helps

If all of these methods are ineffective, there are several alternative solutions:

• 📵 Turn off missed call notifications from hidden numbers. To do this, in the Phone app, go to Settings → Notifications and disable the Unknown Numbers option.
• 🔕 Use the second number (for example, through Google Voice or virtual number). SIM) For important contacts, and leave the main number only for outgoing ones.
• 📱 Buy a separate phone with Dual support SIM and use one SIM-Call card only for calls (e.g. Redmi) A2+ 5-7,000. ₽).

The last option is to change the operator to one who offers more stringent spam filtering, according to Roskomsvoboda, Tele2 is the best at this task (blocks up to 80% of hidden calls at the network level).

FAQ: Frequent questions about blocking hidden numbers