Blocking Unknown Inbound Calls on Xiaomi Redmi

Constant spam calls, intrusive service offers, or simply silent subscribers can turn the life of a smartphone owner into chaos. Owners of Xiaomi and Redmi devices often face the need to quickly limit the circle of those who can reach them. Fortunately, the shell of MIUI and HyperOS offers powerful built-in tools for filtering traffic that do not require the installation of third-party applications.

System settings allow you to flexibly manage your contact list, weeding out unwanted calls before the call rings. You can completely silence anonymous numbers or configure smart filters that will only miss important calls. In this article, we will discuss all the available methods for protecting your personal space.

Consider both the standard blacklist features and the more advanced rules-based locking capabilities, and understanding these mechanisms will help you build a robust noise shield. Let's move on to the practical steps of customizing your device.

Use of the built-in blacklist in MIUI

The easiest and most reliable way to do this is to use the regular Security app, which is pre-installed on every Xiaomi smartphone, which is integrated deep into the system and is more stable than any other third-party counterpart. You don't have to download anything to get started, just find the menu you want in the folder with system utilities.

Open the Security app and find the Lock section. This is where all call and message filtering settings are concentrated. The interface may vary slightly depending on the firmware version, but the logic remains the same for all models, whether it is a budget Redmi Note or a flagship Xiaomi 13.

Inside the lock menu, you'll see a list of already locked numbers and control buttons, where you can manually add specific contacts that you don't want to hear anymore, and just click on the plus icon and select a number from the phone book or enter it manually.

• 🛑 Click on the menu button (three dots) in the corner of the screen to access the advanced settings.
• 📞 Select the “Blacklist” option to see the current locks.
• ➕ Use the add button to manually enter spammer numbers.
• ⚙️ Go to the Rules Settings to Automate the Process.

⚠️ Note: When you block a number through a blacklist, the caller will hear a "busy" signal or short horns, depending on the operator.

It is important to note that the standard blacklist works by prohibiting specific numbers, and if spammers change SIM cards, this method will require constant manual updates of the database, so it is better to use automatic rules to combat mass spam, which we will talk about later.

Automatically locking unknown numbers

MIUI’s Unknown Number Lock feature works differently than a simple blacklist, which sifts out calls that aren’t saved in your contact book, ideal for those who only expect calls from friends, colleagues, and delivery services whose numbers are already recorded.

To activate this mode, go back to the Lock menu and click on the gear icon (Settings). Find the "Block Rules" or "Antispam" section. Here you will need to enable the "Block Calls from Unknown Numbers" option.

The way to setup: Security → Lock → Settings (cogs) → Locking rules → Block calls from unknown numbers.

Once activated, all incoming calls from numbers that are not in your contacts will be automatically reset. You won't even see a missed call in a standard log, but you'll find a lock entry in the Security application log. This creates silence, but requires discipline: if you're waiting for an important call from a courier or a doctor whose number you don't have, the call won't take place.

• 📂 Go to the locking rules settings in the security application.
• ✅ Activate the switch to block unknown numbers.
• 📝 Make sure all important contacts are stored in your phone’s memory.
• 🔍 Check your lock log regularly for missed important calls.

There is also a softer option, which is to block hidden numbers, which is the number that the subscriber deliberately concealed before the call (defined as “No ID” or “Hidden Number”). Such calls are often used by fraudsters. In the locking rules settings, you can check “Block hidden numbers”, and such calls will be cut off, and ordinary unfamiliar numbers will pass.

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Before you enable a hard lock of unknown numbers, make sure that you keep contacts of all delivery services, taxis and clinics that you use.

Blocking through the standard “Phone” app from Google

Many modern Xiaomi and Redmi smartphones, especially global versions, come with a standard call from Google instead of the branded MIUI Dialer shell, an option that is even more effective in fighting spam thanks to Google's built-in database.

Open the Phone app (blue handset) and click on the three dots in the top right corner. Select Settings. Next, look for Number and Spam Definition (or Caller ID & Spam), and there's a powerful filtering toolkit.

Activate the Number and Spam Switch, which will check incoming numbers against Google’s global complaint database, and if the number is marked as spam by multiple users, you’ll see a red alert or automatic reset if the option is enabled.

The menu also offers the option to "Automatically filter suspected spam calls," which, if activated, will not ring at all when the call arrives, but will simply record it in a missed log marked "Spam," which eliminates unnecessary noise and stress.

⚠️ Note: Using a Google number detector means sending incoming calls to the company’s servers for verification, and if you’re critical to the complete confidentiality of metadata, this method may not be appropriate.

The “Do Not Disturb” Regime as a Radical Measure

Sometimes you don't just need to filter out spam, but you need to keep it quiet, leaving it to a narrow circle of people, and Android has a Do Not Disturb (DND) mode, and Xiaomi's smartphones have advanced settings to create a whitelista of contacts.

You can activate mode through the notification curtain (moon icon) or in the Sound and Vibration → Do Not Disturb. The main task here is to set the exceptions correctly. By default, the mode can block everything, but we will set it so that only select ones are allowed to pass.

In the exclusion menu, select "Calls" or "Calls" and you can set the "Contacts Only" or "Favourites Only" rule, and if you select "Favourites Only," only the people you add to the special "Favorites" list in the phone book will be able to call.

• 🌙 Enable Do Not Disturb Mode through Control Center.
• 👥 Set up exceptions for contacts or favorites.
• ⭐ Add important numbers to the “Favorites” list in contacts.
• 🔕 Make sure that re-calls are turned off if complete isolation is needed.

Also in the Do Not Disturb settings, there's a useful option called "Repeat Calls," which, if it's on, will get a call from the same number a second time in 15 minutes, and it's simple: if you call twice, something urgent has happened.

Use of third-party applications for protection

When MIUI is not built in, specialized applications come to the rescue, with Getcontact, NumBuster and Kaspersky Who Calls leading the way, using crowdsourcing, a user-generated database.

The advantage of these apps is that they have a huge database of spam numbers that are updated in real time, and if someone in your city gets a call from a scammer and tags a number in the app, you're already protected from it, but it has its own setup and use features.

When you install an app like Getcontact or NumBester, it will request access to your contacts and call log, which is necessary for the detector to work and load the database, and once installed, the app integrates into the call system and starts intercepting incoming calls for verification.

Example of settings in NumBuster:


1. Install the app from the Play Store.




2. grant access rights to calls and contacts.




3. Insert the function "Spam blocking".




4. Go to Settings → Block → Add the rule “Block all hidden”.

Some antivirus applications may consume extra battery power because they are constantly active in the background, and transferring your phone book to third-party servers (even for security reasons) is a compromise on privacy.

• 📱 Download the anti-spam app from Google Play.
• 🔐 Provide the necessary permissions for the filter to work.
• ⚙️ Set the level of aggressiveness of the lock in the application menu.
• 🔋 Watch your battery consumption if the app is running in the background.

Frequently Asked Questions (FAQ)

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The combination of the built-in MIUI filter and Google number detector provides maximum protection without the need to install heavy third-party apps.

To sum up, Xiaomi’s ecosystem provides a comprehensive toolkit for dealing with unwanted calls: Start by setting up the built-in lock rules, as they are the most energy efficient and safe. If spam continues, connect heavy artillery in the form of number detectors or full isolation mode.

Remember, no system gives you 100% guarantee, because spammers are constantly changing numbers. However, properly configuring filters will weed out up to 95% of all junk traffic, saving your nerves and time. Regularly update databases and check settings after you update your Android or MIUI system.