How to permanently block calls from unknown numbers on Xiaomi Redmi 9: from standard settings to hidden MIUI chips

Spam calls from scammers, intrusive loan offers and “your parcel is waiting” – these are the problems faced by every second owner of Xiaomi Redmi 9. According to the statistics of Truecaller for 2023 year, Russia is in the top-20 countries by number of spam calls, and unknown numbers are up to 40% All incoming calls, smartphone owners MIUI (including Redmi 9 Android 10/11) have unique tools to combat this scourge – from built-in functions to hidden settings, which are not written even in the official documentation.

In this article, you will find 5 proven ways to block unknown numbers, from basic to advanced, including instructions for root-right users. We tested each method on Redmi 9 (versions of MIUI 12.5-14) and highlighted those that work even without installing third-party applications.

Why the standard lock in Redmi 9 doesn’t work against spam

Many Xiaomi users complain that after adding a number to the blacklist (Settings → Lock numbers), calls still pass, the reason lies in three key features of MIUI:

• 🔄 Dynamic numbers: Spammers use virtual number services (such as Zadarma or Sipnet) that generate new combinations every time they call.
• 📞 Caller swap ID: Fraudsters fake the ID of the caller, posing as banks or government agencies. MIUI It does not analyze calls like spam.
• 🚫 Android Restrictions: Starting with Android 9 Pie, Google has tightened its policy on phone logs, with apps (including system ones) prohibited from blocking calls without explicit user permission.

In addition, Redmi 9 has disabled the Xiaomi Spam Filtering feature by default, which could automatically detect fraudulent numbers, and it needs to be enabled manually, as we will discuss in the next section.

⚠️ Note: If you use two of these SIM-Redmi 9, the number lock works separately for each card. SIM It won’t protect you from calling the second.

Method 1: Enabling built-in spam filtering into MIUI

Xiaomi has integrated a spam protection system into the firmware, but it is disabled by default, and activating it will automatically block numbers marked as fraudulent in the Xiaomi Cloud database.

1. Open the phone application (pipe icon).
2. Click on the three dots in the upper right corner → Settings.
3. Choose Blocking and Spam Filtering.
4. Activate the switches: 🔘 Spam filtering (main function) 🔘 Display notifications about blocked calls (optional)

Sources of spam

Xiaomi Cloud

Local database

Once activated, all calls that are recognized as spam will be automatically reset, and in the call log they will be marked with a red exclamation point. Importantly, this feature only works for numbers already entered in the Xiaomi database. It does not block new unknown numbers.

Spam filtering is enabled in phone settings |

Xiaomi Cloud and local base sources activated |

Updated MIUI firmware to the latest version|

Checked function test call-->

How to update the spam number database:

Xiaomi’s database updates automatically when you connect to the internet, but you can manually run the check:

1. Go to Settings → About the phone → System update.
2. Press three points. → Update the spam database.
3. Wait for the process to be completed (it will take 1-2 minutes).

⚠️ Note: If you use Redmi 9 with custom firmware (like LineageOS), the built-in spam filtering won’t work.

Method 2: Manually lock numbers through a call log

If you get a specific number you don't know, you can manually lock it right from the call log, which is suitable for static numbers (such as intrusive collectors or advertising agencies), but is useless against dynamic spammers.

Instructions:

1. Open the Phone app and go to the Journal tab.
2. Find the number in the list and click on it.
3. In the window that opens, select Block (Blocking Sign icon).
4. Confirm the action by pressing OK.

To manage blocked numbers:

1. Go to the phone settings → Lock numbers.
2. Here you will see a list of all the blocked contacts.
3. To remove the number from the blacklist, swipe it left or click Delete.

Important: MIUI 14 for Redmi 9 has a feature called “Blocking by Template”, which allows you to prohibit calls from numbers that start with certain numbers (for example, 8-900-*), This option is hidden in the developer menu and requires activation.

Method 3: Use of third-party applications (Truecaller, GetContact)

If the built-in MIUI tools fail, specialized applications come to the rescue.

• 📱 Truecaller: Base of 300+ It's a million numbers, it detects spam in real time, and it requires access to contacts and SMS.
• 🔍 GetContact: Shows the "name" of an unknown number based on feedback from other users.
• 🛡️ Hiya: Blocks robbrae and scammers, integrates with MIUI conflictless.

How to set up Truecaller on Redmi 9:

1. Download the app from Google Play.
2. At the first start, allow access to: Contacts (to identify calls) Call Log (to block) SMS (optional, to filter spam messages)
3. In the Truecaller settings, activate: 🔘 Blocking spam 🔘 Show notifications about blocked calls 🔘 Auto-update spam database

For maximum protection, we recommend combining Truecaller with built-in MIUI filtering. In this case, the Xiaomi base is triggered first, and then the Truecaller base.

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If after installing Truecaller stopped coming SMS from banks, add their numbers to the white list in the application settings (section "Exceptions").

Method 4: Blocking through operator settings (MTS, Beeline, Tele2, MegaFon)

Russian operators provide their own spam protection services that work at the network level – before the call reaches your Redmi 9.

How to activate the protection:

1. Open the phone app on Redmi 9.
2. Enter. USSD-command for your operator (see table above).
3. Press the call button.
4. Confirm the connection of the service in response from the operator.

Once activated, all spam calls will be blocked at the network level, and you won't even see them in the call log, but there are two drawbacks to this method:

• ❌ Not applicable to international numbers (for example, +375, +380).
• ❌ Can block legitimate calls (e.g. from delivery services).

Method 5: Advanced Methods (for root-right users)

If you're ready to experiment, there are additional ways to block on Redmi 9 with root rights, which require technical skills but give you 100% control over incoming calls.

Method 1: Editing the blacklist.xml file

MIUI stores the list of locked numbers in the system file, and with root rights, you can edit it manually:

1. Install a file manager with root support (e.g., Root Explorer).


2. Go on the path: /data/data/com.android.providers.contacts/databases/contacts2.db




3. Open the database and find the blacklist table.




4. Add numbers in the format: +79123456789| The name of the spammer |1 (where 1 is the type of lock).




5. Save the changes and restart the phone.

Method 2: Using the Xposed Call Blocker Module

If your Redmi 9 has an Xposed framework installed, you can use the module to flexibly configure the lock:

1. Download the Call Blocker module.
2. Activate it in the Xposed menu.
3. Reboot the phone.
4. In the module settings, add the lock rules by: Number prefixes (for example, +375* for Belarus) Keywords in Caller ID (for example, Bank, Police) Time of day (for example, block all calls from 23:00 to 8:00)

⚠️ Warning: Incorrect editing of system files may result in data loss or a cyclical reboot of Redmi 9. Before making changes, back up through Settings → Additionally. → Backup and reset.

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Advanced locking techniques (root/Xposed) offer maximum control, but require technical skills and can disrupt system stability. For most users, built-in MIUI+ Truecaller features are enough.

More tips: how to reduce the number of spam calls

In addition to blocking, you can reduce the likelihood of your number getting into spammer databases, as recommended by cybersecurity experts:

• 🔒 Do not publish the number in the public domain: Remove it from social networks, forums and ads on the Internet Avito/jule.
• 📝 Use the “second number”: Use a virtual number to register for websites and services (for example, via SMS-Activate or OnlineSIM).
• 🛡️ Connect the service "Antispam" from the operator: Even if you do not block calls, the operator will mark them as spam in Caller ID.
• 🔄 Update regularly MIUI: In new versions of firmware Xiaomi improves spam filtering algorithms.

How to check if your number has been in the spammer databases:

1. Go to the NumLookup website.
2. Enter your number in an international format (e.g. +79123456789).
3. Check if your number is in the open database.
4. If data is found, request their deletion through the feedback form on the site.

According to Kaspersky, 68 percent of spam calls come to numbers that have been posted online at least once, and even if you delete a number later, it will remain in search engine caches and spammer databases.

FAQ: Frequent questions about Redmi 9 call blocking