How to block unfamiliar numbers on Android Xiaomi: Full Guide

In today's world, smartphones have become not just a means of communication, but a digital extension of our personalities, through which a huge flow of information passes. Unfortunately, along with useful calls, we receive dozens of unwanted contacts every day from intrusive advertising agencies, telemarketers and scammers. For owners of devices based on MIUI and HyperOS, the issue of protecting personal space is especially acute, since standard methods may not be obvious to the beginner.

The Android system in conjunction with the shell from the Chinese manufacturer offers powerful built-in traffic filtering tools, which are often more effective than third-party solutions. SIM-And through the security system that's built directly into the firmware, understanding these mechanisms will allow you to have complete control over who can reach you.

In this article, we will take a look at all the existing ways of isolating spam, from simple settings in the phone book to advanced scenarios of locking on a masked number, you will learn how to set up automatic screening of calls that are not saved in your contacts, and how to use cloud databases to identify scammers.

Use of the built-in blacklist in the Phone app

The fastest and most affordable way to restrict access to specific attackers is to use the functionality of the standard Phone application. In the MIUI shell, this tool is integrated deep enough to create lock lists without installing additional software. To add a number to the blacklist manually, you need to open a call history or contact list, find the object you are interested in and click on it.

Once you open a contact card or detail a call, you should find a three-point button or menu icon that hides the "Block" option. When you activate this feature, the system marks the contact as prohibited, and any attempts to communicate on its part will be interrupted automatically.

⚠️ Note: When manually locking, it is important to check if you have accidentally blocked an important number, as missed calls from such contacts will not appear in the call log, which can lead to the loss of important information.

To manage the blocked number list, there is a separate section in the app settings. Go to the call settings menu, select "Block" and you will see a complete list of all prohibited contacts, from here you can delete the numbers from the list if you no longer need to block, or add new entries by manually entering them through a special input interface.

System blacklisting has a number of advantages, including no need for third-party permissions and minimal impact on battery power, but it has a limitation: it is only effective against specific numbers that you know. If spammers use spoofing technology or call from different SIM cards, manually adding each new number will be inefficient and time consuming.

A key feature of this module is its priority: the incoming call is checked at the system level before the phone starts making the sound of the call, which ensures that you do not wake up in the middle of the night even the most persistent robot caller, if his number is already in the lock database, the accuracy of this mechanism depends on the relevance of your database of prohibited contacts.

Set up a lock on all unknown numbers

A more radical but highly effective method of combating phone terrorism is to lock all numbers that are not in your phone book, which is ideal for those who expect calls only from friends, colleagues and services with whom they have already been contacted, activating this mode makes your smartphone an impregnable fortress for any cold call.

To enable this feature, you need to go to the Security settings or directly to the Phone settings, to the Lock section. Here you need to find a switch called Lock Unknown Numbers or Lock Hidden Numbers. Once activated, the system algorithm will check each incoming call for your contacts.

If the number is not found in the address book, the call will be automatically rejected, which creates a situation where you can miss an important call from a courier, doctor or potential employer if you do not previously save their number, so before turning on this feature, it is recommended to carefully analyze your need for open channels.

There's also a more flexible setup that allows you to block only hidden numbers, which are those that have a number detector turned off at the operator level, which is less aggressive and doesn't cut you off from the world, but effectively removes the most anonymous and often fraudulent callers. You can find this option in the same lock settings menu, usually it's a separate item.

Using Contact Only requires periodic monitoring of missed calls, as the system may not even show the fact of an attempt to communicate in a standard log. In some versions of MIUI, there is a separate log of blocked calls, where all rejected calls get into the system, which allows you to call back if necessary.

Working with the Antivirus application and the security center

In the Xiaomi ecosystem, the central security management node is the Security app, which combines antivirus, cleaner and, importantly for us, smart number detector functions, and uses databases updated by Tencent and other partners to identify spam calls before the phone rings.

To set up a smart lock, open the Security app and look for the Antispam section. Here you will see the Call Lock switch that needs to be activated. Within this menu, you can select the level of filter aggressiveness, enable blocking of advertising calls, scammers' calls and even deliveries' calls, if they are tagged in the database.

One of the most useful features is the ability to set the lock by prefix, which allows you to block all numbers starting with a specific city code or mobile operator, if you know that this is where the main spam flow comes from, and this lock mask works at the level of analyzing numbers and does not require a specific number in the blacklist.

It is important to update your anti-spam databases regularly, as scammers are constantly changing numbers. Security settings usually have automatic updates, but periodic manual checks will not hurt. Current databases allow the system to recognize new cheating patterns and tag them with appropriate tags on the incoming call screen.

You can also set the behavior of the phone when you receive a blocked call in this section, so you can choose whether the phone will simply drop a call, send a busy call, or not give any audio signals at all, giving the caller a view of the phone being turned off, giving the user full control over how their device responds to unwanted intrusion.

Blocking through messages and SMS-filter

Often, telephone spam is accompanied by a stream. SMS-Advertising messages that are not only annoying, but also occupy space in the device’s memory. Xiaomi smartphones have a powerful message filter that works similarly to a call filter. It can recognize keywords and senders by automatically hiding such messages in the Spam folder».

To activate the protection from SMS-Spam, go to the Messages app, click on the menu (three dots or gear) and select "Anti-spam settings." Here you can enable blocking of messages from unknown numbers, as well as configuring filters for keywords. For example, by adding the words “credit”, “winning” or “promotion”, you will automatically hide all messages containing this vocabulary.

The system allows you to create your own lists of authorized senders, messages from which will never be checked by the filter, which is useful for bank service codes, delivery services and two-factor authentication, which can be mistaken for spam due to a short number or a specific text format.

We must not forget that SMS-Filters can be useful not only for advertising, but also for phishing protection. Messages with links to suspicious resources often contain characteristic markers that Xiaomi’s security system successfully identifies. Regularly browsing your spam folder (at least once a week) will help you make sure that nothing important gets there.

Third-party applications for extended protection

While MIUI’s built-in tools are very effective, there is sometimes a need for more specialized solutions: Third-party applications from the Google Play Market, such as Truecaller, GetContact or Yandex.Definition, have their own, often more extensive databases of numbers generated by users themselves.

The principle of such applications is to reconcile the incoming number with a huge cloud base. If the number is marked by other users as “Spam” or “Fraudsters”, the application will block the call or give a bright warning to the screen, this is especially true for new numbers of scammers who have not yet been included in the official databases of operators or system updates Xiaomi.

However, using third-party number identifiers requires broad permissions. The application needs access to your contacts, call history and SMS to work properly.This poses certain privacy risks, since your data can also be used to replenish the common base. (weighing the risks), many users prefer to use them only for identification, leaving the lock function system.

When installing such applications on Xiaomi, it is important to correctly configure autostart and work in the background. The aggressively system saves battery power and can kill the application process, which will stop working at the right time, you need to lock the application in memory and allow it to auto-start in the battery settings.

National Registry and Spam Complaints

Spam is not only fought at the device level, but also at the state and telecom operators level, for example, in Russia, there is a mechanism for complaints about intrusive advertising through operators or Roskomnadzor. Although this does not give an instantaneous effect of blocking on your particular phone, mass complaints lead to the blocking of entire pools of numbers by operators.

Many operators offer paid and free spam protection services ("Antispam", "Number Detector"). These services work on the network side, meaning the call is blocked before it even reaches your phone, which unloads the smartphone processor and saves battery life, since the device does not need to process the incoming signal.

To connect such services, it is usually enough to send USSD-Often the basic version of spam protection is provided free of charge, and advanced features (name determinant, personal blacklist in the cloud) require a subscription.

💡

Use Do Not Disturb mode for complete silence, and in this mode, you can only allow calls from selected contacts, which is the most stringent filtering method available on Android without third-party software.

A comprehensive approach that combines the settings of the Xiaomi smartphone itself, operator services and user prudence, gives the best result.

Frequently Asked Questions (FAQ)

💡

The most effective protection is achieved by combining built-in MIUI antispam and operator services, which creates a two-tier filter for unwanted calls.