How to prevent calls from an unknown number on Xiaomi

Constant calls from spammers, scammers or just obsessive organizations have become a real problem for smartphone owners, especially for users of the Xiaomi ecosystem, whose MIUI shell and the new HyperOS have powerful but not always obvious filtering tools. If you are wondering how to prohibit calls from an unknown number to Xiomi Android, we have come to the right place: we will analyze all the standard methods and third-party solutions.

Unlike many other manufacturers, Xiaomi has integrated the Antispam feature directly into the system dialer, which allows you to block unwanted calls without installing additional software, which saves battery power and RAM of the device. However, standard settings are often hidden in deep menus or require activation through the region.

There are several layers of protection, from simply locking all hidden numbers to cleverly filtering promotional offers, and in this article, we’ll take a closer look at how to set up a blacklist, use built-in databases, and apply radical methods to cut off calls from everyone who isn’t in your phone book.

Use of built-in MIUI and HyperOS blocker

The most effective way to combat unwanted calls is to use native shell functionality, which is the Security app on Xiaomi, Redmi and Poco, which works at the deep end of the system, intercepting calls before they even bother the user with an audible signal.

To access the settings, you need to open the Security app (green zipper icon). At the bottom of the screen or in the tool list, find Antispam. This is where all the levers of incoming traffic are concentrated. The interface may vary slightly depending on the version of MIUI, but the logic remains the same.

Inside the Antispam menu, go to the settings (usually the gear in the corner). You will be interested in the Lock section. Here you can activate the Block Unknown Numbers switch. It is important to understand the difference: Unknown in the context of Xiaomi often means a number that is not in your contacts, not just one that has an ID hidden.

⚠️ Warning: Activating the lock function for all numbers that are not in contacts may cause you to miss an important call from a courier, doctor or employer if their number is not stored in your phone’s memory.

Also available in this menu is the "Block Hidden Numbers" setting, which cuts off exactly those calls where the subscriber used the #31# code or operator service to hide his identifier, and once the corresponding switches are turned on, the system will automatically reset such calls.

Radical method: Blocking everyone except contacts

If the spam flow has become intolerable and you're willing to risk missing calls from strangers, you can use Contact Only mode, a technique often referred to as "whitelisting," although technically it's an inverted blacklist, and ideal for older people or during times of aggressive phone fraud.

You can do this through standard call settings. Open the Phone app and click on the three dots in the top right corner. Select Settings, then find the Lock or Blacklist section. In some firmware versions, this item is displayed separately in the main system settings menu.

Here you need to find an option that sounds like “Block calls from unknown numbers” or “Allow only from contacts.” Depending on the model (Redmi Note, Xiaomi Mi, Poco F), the wording can be cooked. The bottom line is one: the phone will ignore any incoming signal if the caller’s number does not match any entry in your address book.

• 📱 Open the phone app».
• ⚙️ Go to the settings menu through three points.
• 🚫 Find the "Block" or "Antispam" item».
• ✅ Activate the “Contact Only” mode».

It's worth noting that emergency services and some service numbers can go through this filter depending on the operator's settings, but you shouldn't rely on this. If you're waiting for an important call, for example, from a courier who calls from different numbers, it's better to temporarily turn off this method.

Setting up smart recognition and databases

The MIUI shell is not only able to block, but also to identify the caller. A database often provided by a partner (such as Truecaller or local databases) allows you to see the tags "Spam", "Adverts" or "Fraudsters" before you take a call. This is not a complete lockdown, but an effective attention filter.

To activate this feature, in the Antispam menu, find Update Databases or Online Services, where you want the app to allow Internet access to download current number lists, and without this step, the phone will only rely on your local lock history.

You can also fine-tune categories, so you can choose which types of numbers to lock automatically and which to simply tag, for example, taxis and delivery can be left, and Marketing and Finance can be blocked.

Using online databases requires the transmission of hashes to verify, which is a trade-off between convenience and privacy. If you are critical to complete anonymity, you should rely only on locally locked hidden numbers.

Blocking through Google Phone (Google Phone)

Many modern Xiaomi smartphones come with a pre-installed number dialer from Google, rather than its own MIUI Dialer. This is typical of global versions released after 2020. The logic of locking is different here, although the functionality remains similar.

Open the Phone app (blue or white handset from Google). Click on the three dots in the upper right corner and select Settings. Find the Locking Numbers section, where the interface is more minimal, but functional.

You will be able to use switches like “Block Unknown Numbers” (hidden ID) and “Block Hidden Numbers” and Google offers a “Spam Filter” feature that uses artificial intelligence to detect suspicious calls, so that when a potential spammer calls, the phone will not call, but will only show a missed call notification marked “Suspicious spam”.

⚠️ Note: Google's algorithms may be wrong, and sometimes legitimate calls from small businesses or individuals may be labeled as spam if the number has received a lot of complaints from other users.

The advantage of Google Phone is that the spam database is updated automatically and globally, without the need for manual database updates, as in the case of MIUI Dialer, which makes protection more relevant in real time.

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Use USSD codes for quick check: dial #31# to hide your number when an outgoing call is made, or *31# to show it if you have a permanent ID lock.

Third-party applications for enhanced protection

If built-in tools are not enough or they work incorrectly, specialized applications from Google Play come to the rescue. The leaders in this niche are Kaspersky Who Calls, Truecaller and GetContact (although the latter is more about the name than about blocking).

Calls Blacklist is minimalist and has no advertising, and it allows you to create complex rules, like locking all numbers that start with a prefix combination or all numbers that don't meet the standard, and it's a powerful tool for advanced users.

To install a third-party blocker on Xiaomi, it is often required to provide special permissions to the app. In addition to standard access to contacts and phone, you need to give permission to “Map on top of other applications” and access to call history. Without this, the app will not be able to reset the call before the phone rings.

• 📥 Download the app from a trusted source (Play Store).
• 🔐 Provide all the requested permissions.
• 📂 Import an existing blacklist (if any).
• ⚙️ Set up auto-start so that the system doesn’t “kill” the process.

Android, and MIUI in particular, can be incorrectly handling an incoming call if two blockers are competing to process it.

Services of telecom operators as an additional barrier

Remember that filtering can be done at the network level, even before the signal reaches your smartphone. The largest operators (the Big Four in Russia and CIS operators) offer antispam services, which can be paid or free, depending on the tariff.

For example, MTS has an antispam service, Beeline has a spam protection service, MegaFon has an antispam service, and Tele2 — «The connection is made through the operator's application, personal account or USSD-These services often use shared databases of numbers marked as spam by thousands of subscribers.

The advantage of network locking is that it doesn’t consume your Xiaomi’s battery and works even if the phone is turned off (the call just won’t pass).

Examples of commands (may vary):


MTS: *111*377#




Beeline: *110*7722#




Megaphone: *555#




Tele2: *155*22#

Using the operator’s services is particularly effective when combined with the built-in Xiaomi blocker, the network cuts off obvious spam, and the phone filters out residues and hidden numbers.

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The combination of the operator’s network protection and the built-in MIUI blocker ensures maximum silence, cutting off up to 99% of unwanted calls.

Frequently Asked Questions (FAQ)