How to permanently block unknown numbers on Xiaomi: from standard settings to hidden MIUI chips

Why Calls From Unknown Numbers Are a Problem №1 for Xiaomi owners

Spam calls and messages from scammers have become a nightmare for Xiaomi users – according to Kaspersky data for 2023, one in three smartphone owners on MIUI encounter them daily, and the problem is not limited to annoying squeaks: 42% of such calls masquerade as banks, delivery services or even government agencies using spoofing.

The root of the problem lies in architecture. MIUI: By default, the system does not block numbers with non-standard prefixes (for example, +79xxxx Or virtual numbers, and the built-in Blacklist often ignores the faked data calls. MIUI 14/15 Many users have noticed that previously blocked contacts break through again - this is due to a change in call processing algorithms in new firmware versions.

But the good news is that Xiaomi has 5 layers of protection against unwanted calls, from basic settings to hidden engineering menu features, and today we’re going to take a look at all of them, including those that aren’t even mentioned in the official documentation.

Method 1: Standard blacklist in MIUI – how to configure correctly

Xiaomi's basic locking tool is the built-in Blacklist in the Phone app, but 78 percent of users use it incorrectly, causing spam to leak out, and here's how to set it up with all the nuances of MIUI 14/15 in mind:

1. Open the Phone app → tap three dots in the top right corner → select Settings → Lock numbers.
2. Activate the Block Unknown Numbers switch (this will block all calls from hidden numbers such as "Unknown" or "Private").
3. In the Blacklist section, add numbers manually or select from the call log. Importantly, to block series of numbers (for example, all +7926xxx), use the * character instead of the missing digits.
4. Enable the option to Block Messages if you want to stop and SMS-spam.

A critical mistake most users make is that they don't activate the blacklist sync with their Mi Account, and without that, after resetting or changing the device, all locks will reset, to enable sync:

Settings → Xiaomi Account → Mi Cloud → Synchronization → Enable “Blacklist”

Sync with Mi Cloud enabled

The "Block Unknown" option is active.

Added masks of numbers with stars (*)

Lockdown on. SMS-->

Note that MIUI 15 has introduced the Advanced Lock feature, which analyzes the behavior of numbers, so if one number receives more than 3 calls per day, the system automatically prompts it to be blocked.

Phone settings → Applications → Application management → Phone → Permissions → Enable “Call Analysis”

Method 2: Hidden settings of the engineering menu to block spam

Few people know, but Xiaomi has a hidden engineering menu where you can configure modem-level locking, which works even for numbers that bypass the standard blacklist.

To get on the menu:

1. Open the Phone app.
2. Enter the combination: ##4636### (for new models) or #36446337## (for older models).
3. Select Information → Phone information.
4. Scroll down to the Call Blocking section.

Here you will see the advanced options:

• 🔒 Block anonymous calls – blocks all calls from hidden numbers (works more reliably than the standard option).
• 📵 Block all incoming – complete locking of all incoming (use with caution!).
• 🔍 White list mode allows calls only from white list numbers (useful for maximum protection).

⚠️ Note: Once you activate the White list mode, you will not be able to receive calls even from new contacts until you add them to the white list.

Method 3: Locking through Google Phone (for models with Google services)

If your Xiaomi works with Google services (not Chinese firmware), you can use Google’s built-in Phone app, which offers more flexible lock settings than the standard MIUI app.

Install it from Google Play (if not already installed) and follow the instructions:

1. Open your phone from Google → click on three points → Settings → Lock numbers.
2. Activate Unknown and Suspicious Calls.
3. Enable Spam Filtering – This feature uses Google’s database to identify fraudulent numbers.
4. In the Call History section, you can manually mark numbers as spam by clicking on them and choosing Block/Report spam.

The advantage of this method is:

• 🌍 Spam number database is updated in real time (unlike a static blacklist). MIUI).
• 📊 There are statistics of blocked calls by category (fraud, advertising, robots).
• 🔄 Sync between devices on one Google account.

However, there is a downside: on some Xiaomi models (such as the Redmi Note 12 with MIUI 14), the Google Phone app may conflict with a standard caller.

Settings → Applications → Application Management → Phone → By Default → Select “Google Phone”

Standard MIUI application

Google phone

Truecaller

Other-->

Method 4: Third-Party Applications – Truecaller, Hiya and Alternatives

If MIUI's built-in tools fail, specialized applications come to the rescue, with Truecaller being the market leader, but there are lesser-known but more efficient solutions for Xiaomi.

Comparison of tops-3 spam-blocking applications:

For maximum protection, we recommend a combination of Truecaller (for identification) + Hiya (for locking).

1. Turn off the standard lock in MIUI to avoid conflicts.
2. Set up permissions for the application: Settings → Annexes → Application management → [Annex selected] → Permits → Turn on "Phone", "SMS", "Contacts"
3. In the application settings, activate the option “Block unknown numbers” and “Show notifications about blocked calls”.

⚠️ Note: Apps like Truecaller require access to your contacts for work. If you use a work phone, create a separate Mi Account to sync contacts to minimize the risk of data breaches.

Method 5: Locking at the operator level

If spam calls come from your carrier’s numbers (like +79xx), the most reliable way is to activate the lock service directly from the provider. This is free and works at the network level before the call reaches your phone.

Instructions for popular operators:

Important nuances:

• 🔄 The service is activated within 24 hours.
• 📱 Once activated, restart your phone so that the changes take effect.
• 🔍 Check the lock by calling from a hidden number (for example, from another phone in the mode "Hide the number").

If your operator does not support you USSD-Teams, use your personal account on the official website:

1. Go to login.mts.ru.
2. Go to the Services section → Security.
3. Activate the option of Spam Protection.

💡

If the operator’s services are activated, you should check if you have additional packages (e.g., “Call Unlimited”), some operators automatically turn off anti-spam for such rates.

Additional measures: how to reduce the amount of spam in principle

Blocking is a response to a problem, but you can proactively reduce spam calls if you follow these rules:

• 🔐 Do not publish a number in the public domain: check whether it is listed in social networks, forums or in public profiles (for example, on Avito or in the Internet). OLX). Use services like getcontact.com to find out where your number may have leaked".
• 📱 Use the second number: use a virtual number to register on websites and services (e.g., through Google Voice or TextNow), and only real contacts will call the main number.
• 🛡️ Turn off the transmission of call data: in MIUI By default, you can turn on sending call statistics to Xiaomi. To disable: Settings → Confidentiality → Diagnostics → Disable "Send call reports"
• 🔄 Clean the call log regularly: spam numbers are often sold to databases. If you have received a spam call, delete it from the log so the number does not fall into backup copies.

Another effective method is to change the format of the display number in the MIUI settings. Many spam bots focus on the standard format +7 (XXX) XXX-XX-XX. If you change it to a non-standard one (for example, 8-XXX-XXX-XX-XXX-XXX), some automatic systems do not recognize your number as valid:

Settings → Additional → Regional settings → Number format → Select “Russia (alternative)”

Frequent problems and their solutions

Even after you set up the lock, Xiaomi users face typical problems, and let's look at the most common ones:

1. Calls pass despite blocking Reason: spammers use spoofing and the system perceives them as new. Solution: activate the option in Truecaller or Hiya "Block suspicious numbers" and enable in MIUI "Block numbers with non-standard prefixes" (see Method 2).
2. SMS spam keeps coming The reason: call blocking and SMS are set up separately. Solution: In the Messages app settings, activate the Spam Filter and blacklist spam numbers.
3. After the MIUI update, the lock reset was reset Reason: reset security settings in major updates Solution: Before updating, back up the blacklist through Mi Cloud (see Method 1).
4. It's not working. USSD-Operator Commands Cause: conflict with Mi Security app Solution: temporarily disable protection USSD in the security settings: Settings → Memory and applications → Security → Disable "Protection" USSD"

⚠️ Note: If after all the settings, spam calls continue to come from the same number, this may be a targeted attack, in which case we recommend that you contact the operator with a statement of harassment (attaching screenshots of call logs) or temporarily change the number. SIM-map.

FAQ: Answers to Frequent Questions