Why Xiaomi’s phone number isn’t blocked: The full guide

When annoying spam or calls from detractors continue to flow to the smartphone despite being blacklisted, it is a natural irritation. Xiaomi device owners often find that their regular security mechanisms are no longer functioning correctly, and this can happen for a variety of reasons, from a banal failure in the Security app to deep system conflicts after a firmware update.

The efficiency of the lock depends on the correct configuration of MIUI and the operation of system services, which can be aggressively optimized to save battery power. If energy saving algorithms "sleep" the process responsible for filtering incoming, the call simply passes through all the barriers. In this article, we will discuss in detail the technical aspects of the blocker and how to troubleshoot.

Don’t ignore the problem, as constant interruptions affect productivity and psychological comfort, and understanding how the operating system handles incoming calls will help you not only mechanically add a contact to the stop list, but also ensure that it is effectively isolated from your device.

System Limitations and Application Operation Security

The security app, built-in security, is the central element of protection in Xiaomi’s ecosystem, and it manages the databases of unwanted numbers, not the standard “calling”, if you add a number through contacts but ignore the settings of the security application itself, locking may not work. Often users forget that access rights for this service can be limited by the system.

In modern versions of the HyperOS and MIUI shell, the memory cleanup algorithms are extremely aggressive. If the Security application is not “important” or is not stored in memory, the system can force the background processes to end, at which point the call filtering mechanism simply ceases to exist until you manually open the application again.

To work properly, you need to check autorun and permission settings. Make sure the security app management menu allows you to work in the background. It's also worth checking if Do Not Disturb mode is enabled in global settings, which may take precedence over blacklist rules.

• 📱 Check if the Security app is installed as the default protection app.
• 🔋 Turn off energy savings for system protection services in battery settings.
• 🔄 Clear the Security app cache through the Storage Management Menu.
• 🛡️ Make sure that the database of antivirus and spam filters is updated to the current version.

⚠️ Warning: Forced shutdown of the System Security application via Task Manager may cause temporary shutdown of protection against all incoming calls, including authorized contacts, before the device restarts.

Special attention should be paid to permissions. The application must have access to the call log and contacts. Without these permissions, it will not be physically able to analyze the incoming number and match it with the list of prohibited. You can check this in the Settings section → Applications → All applications → Security → Permissions.

Synchronization problems and duplication of contacts

One of the most common reasons why a blacklist ignores certain numbers is the conflict between the phone’s local database and cloud services.If you sync contacts through a Google Account or Mi Cloud, you may experience a situation where the number is locked on the device, but when synchronized, it is replaced with a “clean” version from the cloud, where there is no lock.

The problem can also be in the format of a phone number record, and the phone is a conservative system, and for it the number +79990000000 and 89990000000 are two different subscribers. If the number on the blacklist is in an international format, and the caller is determined by the system in the national (or vice versa), the lock will not work, this is a classic error that occurs in 80% of cases of unsuccessful locks.

It is recommended to bring all records in a single international format, which will eliminate confusion when identifying the caller by network operators and internal modules of the smartphone, and it is worth checking whether this contact is not maintained under different names or in different groups (SIM-Map, phone, Google account).

Duplicating phone book records also confuses sorting algorithms. SIM-In the memory of the phone with different lock settings, the system can select the record with the least privileges (i.e., without locking.

The Impact of MIUI Updates and Firmware Bugs

After major MIUI shell updates or a HyperOS transition, users often notice defaults in standard features, developers can change the structure of system files or paths to blacklist configuration files, and as a result, the old lock rules are no longer readable by the new software.

There are cases where network assistant settings have been dropped after an update, and in such situations, a blacklist formally exists, but the module responsible for applying it to the incoming data stream is not activated, and it is a software bug that requires manual intervention or waiting for a patch from the manufacturer.

If the problem occurs immediately after the update, it makes sense to reset the network settings or, in extreme cases, completely reset the device. However, before drastic measures, try simply to switch the mode of operation of the number detector. Sometimes it helps to temporarily disable and re-enable the lock function in the settings.

Conflicts with third-party applications and operator

Installing third-party number detectors like Truecaller, GetContact or Yandex with Alice can create conflicts with Xiaomi’s native system.These applications request full rights to manage calls. When they are prioritized over the system blocker, MIUI rules are ignored in favor of third-party application rules.

And you also have to consider the mobile operator itself, because many providers have paid antispam services that run at the network level before the call reaches your smartphone, and if they're activated but not configured correctly, they can skip spam as legitimate traffic, or they can block important calls, giving you the illusion of a phone crash.

It is recommended to leave only one active filtering tool.If you use a powerful third-party app, disable the blacklist in Xiaomi settings to avoid double call processing, which can lead to a call reset or, conversely, to its miss due to a timeout.

• 📞 Check the connected services with your mobile operator (e.g. Antispam»).
• 🚫 Remove or disable duplicate applications to block calls.
• ⚙️ In the Security app settings, make sure that the “Block” tick is ticked».
• 📲 Check if the blocker app is in “Sleep” or “Background Limitations” mode».

⚠️ Note: Simultaneous use of the system blocker Xiaomi and third-party application with administrator rights can lead to a freeze of the call interface or complete absence of a beep when calling.

Also, some virtual numbers (VoIP) or numbers that hide their ID (Hide Number option) may bypass standard filters because the system cannot identify them as blacklisted, in which case only complete blocking of unknown numbers helps if this feature is supported by your firmware version.

Setup of locks for different versions of MIUI

The interface and logic of the blacklist can vary significantly depending on the shell version. In older versions of MIUI (e.g. 11 or 12), settings were deep in the contacts menu. In newer versions (MIUI 13, 14, HyperOS), management is taken out in a separate application or integrated into the call menu more explicitly.

For current firmware versions, the path to settings is usually: open the Phone app, click three dots in the corner, select Settings → Prohibited Numbers (or Antispam). Here, it is important not only to add a number, but also to check whether the “Block Calls from Prohibited Numbers” switch is activated.

In some regions (European versions of firmware), the function of the detector and blocker can be curtailed due to privacy laws (GDPR), in which case the staff blacklist may not work correctly or not, and users have to resort to changing the region in the settings of the phone or using third-party solutions.

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If you switch from a smartphone region to China or India, the functionality of the blocker can expand, but there will be more advertising in system applications.

Special attention should be paid to the function “Keyword Blocking” in the SMS. It often works regardless of the blocking of calls. If your goal is to stop spam messages, make sure you set up the section. SMS-filter, not blacklist calls.

Radical methods and resetting settings

If neither of the software methods worked, the system file that stores the blacklisted database may have been corrupted, in which case cleaning the phone and contact app data helps, not removing your personal contacts (if they are synced to the cloud), but resetting all call settings, logs and blacklists to factory state.

To do this, go to Settings → Apps → All apps. Find Phone (or Calls) in the list, click Clear → Clear Everything. Repeat the same for Contacts. Once you reboot, the phone will be as new as your communication settings, and you will have to blacklist the numbers again, but with a clean configuration.

In extreme cases, when the problem is global and affects the entire system (for example, after a failed beta test), a full reset (Wipe Data) may be required.Be sure to make a full backup of all important data before this, as this procedure will delete all the contents of the internal memory.

It’s also worth checking for system updates. Often Xiaomi releases hotfixes that fix critical bugs in the phone. Go to Settings → About the phone and click on the MIUI version to check for new service packs.

⚠️ Attention: Clearing the phone app data will delete the history of all incoming and outgoing calls. If you need a call log for a report or evidence, pre-export it or take screenshots.

Frequently Asked Questions (FAQ)