How to block calls from unknown numbers on Xiaomi

Constant calls from spammers, intrusive managers and automatic robots have become a real scourge of modernity, turning the smartphone from a useful tool into a source of constant stress. Owners of Xiaomi and Redmi devices often face a situation where an incoming call comes from a hidden number or is marked as “Unknown”, making it impossible to use a standard blacklist by number. This problem can be solved in several ways, ranging from built-in shell functions. MIUI and ending with the operator's settings.

In this article, we will take a closer look at all the available methods of protection against unwanted contacts that are relevant for 2026-2026. You will learn how to activate Do Not Disturb mode with smart exceptions, how to use powerful antivirus algorithms to filter traffic and what USSD commands will help redirect empty calls. It is important to understand that there is no universal “Block Everything” button, as this can lead to the skip of really important calls from doctors or couriers.

However, the right combination of settings cuts down to 99 percent of the noise, and we'll look at the nuances of working with numbers that aren't saved in contacts, and explain the difference between locking Hidden Numbers and Unknown Subscribers in Android terminology. Get ready to finally have your phone quiet when it's needed and available at important moments.

Use of built-in MIUI and HyperOS blocker

The MIUI shell and the new HyperOS have one of the most advanced built-in security modules of all Android smartphones, a tool known as Blocker that is integrated deep into the system and does not require the installation of additional applications, which positively affects the autonomy of the device. To access the basic settings, you need to open the Security application, which by default has a green icon with a shield, and find the corresponding partition there.

Inside the blocker menu, we're interested in the Blacklist item, which is where all the rules for filtering incoming calls are stored. The standard configuration often only offers manual additions, but to combat unknown subscribers, you need to activate special switches. Click on the gear icon in the upper right corner of the screen to go to the advanced filtering settings.

You'll see several lock categories in the menu that opens, and we're interested in the "Block Unknown Numbers" option, and it's important to keep in mind that "Hidden Number" is when a subscriber specifically conceals their ID when they call, and "Unknown Number" is any number that isn't in your phone book, and activating that option will cause any call from a number that isn't recorded in the contacts to be automatically reset by the system.

It’s worth noting that in some regions and firmware versions, the logic of the work may be slightly different, for example, in global versions of the software, features may be limited compared to Chinese builds due to local communication laws. If you don’t find the right switches, you may want to update the Security app through the built-in GetApps store.

Setting up the "Do Not Disturb" mode for total silence

Xiaomi’s Do Not Disturb is a much more flexible tool than simply turning off the sound, which allows you to create complex scenarios where the phone ignores incoming calls while skipping alarms or emergency notifications, ideal for those who want to sleep soundly or work in silence without fear of missing a call from loved ones.

To set up call filtering in this mode, go to the main Settings → Sound and vibration → Do not disturb. Here you can set an automatic turn on schedule, for example, from 23:00 to 07:00. However, the key point is the section “Allow calls” or “Exclusions”. By default, the system can miss calls from favorite contacts or repeat calls (if the same number calls a second time within 15 minutes).

⚠️ Note: When activating Do Not Disturb mode with strict restrictions, you can skip an emergency call from a doctor or employer if their number is not on the favorites list.Be careful with the "Nobody" or "Favourite Only" settings».

For maximum protection from unknown numbers in this mode, select Contacts Only or Favorites, in which case all other calls, including those calling from a hidden number, will be blocked at the system level, and the caller will hear the signal “busy” or horns, depending on the operator’s settings, and the screen of the smartphone will not even light up.

The convenience of the mode is also the ability to quickly switch through the Control Panel. You can add a "Do Not Disturb" icon to the notification curtain and activate it with a single touch when a meeting or rest time begins, which is faster and more efficient than manually blacklisting numbers each time.

Blocking through Google Phone Settings

Many new Xiaomi models, especially global versions, come preinstalled with Google’s Phone app instead of the standard MIUI call. The interface is different here, but the lock functionality is also present and works very efficiently. Open the Phone app, click on the three dots in the top right corner and select Settings.

In the settings menu, look for the “Block Numbers” section, and here you will see a list of already blocked contacts and the “Block Unknown” switch. In Google terminology, this item is often called “Block Calls from Unknown Numbers.” Activating this switch will prevent calls from numbers that are not displayed in the number definition (hidden) or not defined.

It is important to distinguish between two types of locking in Google Phone:

• 📞 Hidden numbers: Subscribers using special codes to hide their ID.
• 📵 Unknown numbers: Any numbers that are not in your address book.

The choice of the specific option depends on your goal. If you are waiting for a call from a courier, but do not want to hear spammers, it is better to use filtering only hidden numbers, if this option is available in your version of the firmware.

Also available in this section is the Spam Filter feature, which uses Google's database to identify and automatically reject calls from known scammers, and it's recommended to keep this feature enabled as it updates in real time and doesn't require manually configuring blacklists.

Application of third-party application-definition

Built-in tools are good, but operator and manufacturer databases are sometimes inferior to crowdsourcing solutions, applications like Truecaller, Yandex (with Alice) or Kaspersky Who Calls have huge databases of numbers labeled by users as “Spam”, “Advertising” or “Fraudsters”, installing such an application can significantly improve the level of protection.

Once the application is installed and the necessary permissions (access to contacts and calls) are granted, it takes over the call function. When a call is made, the application checks its number against its database in the cloud. If the number is marked as spam, the call is automatically blocked or marked in red. To block Unknown (empty) numbers, the application settings also have appropriate switches in the settings of such applications.

However, the use of third-party determinants has its own nuances, which you need to know:

• 🔒 Privacy: You transfer your contact database to the developer of the matching app.
• 🔋 Energy consumption: The application's background operation can consume battery power.
• 💰 Paid Features: Many locking features can only be available in Premium versions.

Despite the downsides, for users who are attacked en masse, this is often the only effective solution, and the combination of the built-in MIUI blocker and a third-party detector (working in pairs) gives the best result, although it can lead to conflicts if both applications try to manage calls at the same time, in which case it is better to leave only one active solution.

Operator service: forwarding and USSD codes

The most reliable way to cut off calls, which works even on button phones and when the smartphone is turned off (while it is registered in the network), is the services of a telecom operator. The largest operators (the Big Four in Russia and analogues in the CIS) offer services like Anti-Determinator (to protect against hidden ones) or smart determinants with a lock function.

You can often use forwarding codes, for example, setting up a class redirect or not being available to voicemail or another number can help, but there are special ones to block hidden numbers. USSD-They vary from operator to operator, so it's best to check the exact combination in your personal account or in support.

Comparison of locking methods at the operator and smartphone level:

For example, for some operators, the *123# code opens the service menu where you can find "Hidden Number Lock" and check the relevance of the codes for your tariff, as conditions may change.

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Check the operator’s personal account: you can often connect Antispam for a month as a test period for free there to assess the effectiveness of protection.

FAQ: Frequently Asked Questions

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A comprehensive approach combining smartphone settings, smart contact lists and operator services provides maximum protection against phone spam and unknown calls.