Spam calls and intrusive offers from telemarketers have become a scourge of modern times, turning a smartphone from a means of communication into a source of constant irritation. Owners of budget but powerful devices such as the Xiaomi Redmi 9 often face a situation when it is urgent to restrict access to unwanted subscribers. Locking a number at the system level allows not only to preserve peace of mind, but also to protect personal data from fraudsters.
The MIUI operating system installed on Redmi 9 offers built-in and flexible tools to filter incoming calls. However, the functionality of the Chinese shell is not always obvious to users accustomed to “pure” Android. In this article, we will discuss in detail all available methods, from standard “blacklist” settings to using third-party software.
It is important to understand that methods may vary depending on the firmware version (Global, EEA or China). The system blocker on Redmi 9 works at the MIUI core level, so resetting call settings can return locked numbers to the list of allowed ones. We will look at the nuances of each approach so that you can choose the most suitable one for your situation.
Use of the built-in "Security" application
The main security tool in the Xiaomi ecosystem is the system application Security, and this is where the main levers of incoming traffic are concentrated. To get started, you need to find a shield icon on your desktop and run it. Inside the interface, you need to scroll down to the Antispam section.
Clicking on this, you'll be taken to the filter control menu, and here the system offers two main protections: SMS blocking and call blocking. We're interested in the latter. When you go to "Call blocking," you'll see the function activation switch and the list of contacts already blocked. The blacklist activation occurs instantly after the corresponding switch is turned on.
The interface allows you to configure rules flexibly, such as “Block Blacklist” or the more aggressive “Block All Unknown Numbers” mode, which is useful if you are waiting for a call only from saved contacts, but it carries the risk of missing an important call from a courier or doctor.
⚠️ Note: When you turn on lock mode for all unknown numbers, make sure you have missed call notifications enabled, otherwise you may not know you have attempted to communicate.
There is a faster way to blacklist a specific number without diving into the deep settings menus. This method is ideal when you just got a spammer call and you want to block it immediately. Open the standard Phone app and go to the call log tab.
Find the Troublemaker number and click on the information icon (usually the letter "i" in a circle or an arrow) next to the number. The call details menu that opens often features the option "Block" or "Add to a blacklist." On Redmi 9 with a MIUI shell, this item can be hidden in an additional menu called at three points in the corner of the screen.
- 📞 Open the call log and find the number you need.
- 🛑 Click on the information icon or three menu points.
- ✅ Select “Block” to instantly ban calls.
You can do the same thing through the Contacts app, and once you find a phone book entry, you can edit a subscriber card. In some versions of the firmware, you have a "Block Incoming Calls" switch right in the contact card, which creates a customized rule for the individual, ignoring the general filtering settings.
What will the caller see?
The caller will hear short horns and then reset. The caller will display information that the call is made, but your phone will be silent or vibrate once, after which the call will be rejected by the system automatically. Set up the lock through the call menu The classic settings path, familiar to many Android users, is also available on Xiaomi Redmi 9. It allows you to manage the lock list through the standard dial menu. Open the Phone app and click on three dots in the upper right corner of the screen to call the drop-down menu. In the list of options, select "Setting", and then you can add the new control button from the access box. The good thing about this method is that it works even if the Security app has been accidentally removed or modified. The same menu often features the Antispam feature, which uses the cloud databases of Xiaomi and other partners to determine ad numbers. The cloud database is updated regularly, which allows you to block even those numbers that are not yet in your personal list. Access method Access speed Functional Dependence on the network Application Security Average Full (SMS + Calls) Required for database updates Log of calls High Only number No phone settings menu Average Advanced Partial Use of third-party applications to block If built-in tools MIUI Google Play offers many alternatives, popular apps like Truecaller, Calls Blacklist or Mr. Number has more powerful algorithms for detecting spam, which can analyze not only the number but also the content of a conversation (with your permission), or check the number against a global user base, but installing third-party software requires caution. These applications require broad permissions to access contacts and calls, and data privacy can be compromised, as number databases are often formed by collecting information from users. To install a third-party blocker on Redmi 9, additional permissions may be required. MIUI aggressively saves battery power and can "kill" the background processes of the blocker. 📲 Download the app from a verified source (Google Play). ⚙️ Give all the requested permits to work with the phone. 🔋 In the battery settings, select No Limits mode for the app. ⚠️ Warning: Do not install two applications to block calls at the same time, this will lead to a conflict of system processes, and calls may stop running at all or, conversely, the lock will stop working. Sometimes you don't have to create a permanent blacklist, you just have to go through a period of silence. In such cases, the Xiaomi Redmi 9 is perfect for Do Not Disturb mode. It doesn't lock the number forever, but it silences all sounds and vibrations at a selected time. You can activate this mode through the notification curtain (the crescent icon) or in the sound settings. Smart setting allows you to create a schedule, for example, from 23:00 to 07:00. In this mode, the phone will ignore incoming calls, but calls from Favorites can pass if you set up an appropriate exception, which is a great way to filter noise without risking losing a really important emergency call. Unlike hard-locking, you control your attention, not your network access, and you block hidden and unknown numbers, and you have a problem with hidden numbers or a code called "Unknown." On Redmi 9 and most Android smartphones, it is possible to block calls where the subscriber has hidden his identifier. This is done through the call settings menu» -> «Incoming call blocking is often a separate Block Unknown Numbers switch, and when activated, any call that does not have a numeric ID will automatically be rejected. This is effective against some kinds of robot callers. However, it is worth remembering that some organizations (banks, clinics, government agencies) can call from hidden numbers or corporate PBX, defined as "Unknown." Locking unknowns can cut off access to important services, so use this feature with caution. Frequently asked questions (FAQ) Will the subscriber see that I blocked it on Xiaomi Redmi 9? Direct notification of blocking the subscriber will not receive. The call will look like a normal one: go beeps, then reset. He may think that you do not take access to important services, so use this feature with caution. If you can not even add a phone number to the phone, if you can not be stored in the phone from the network, if you are not even if you are not locked in the phone, if you are not locked in the phone, if you are not locked in the phone, or if you can not have a phone, if you are not have a phone number from the phone, if you are not stored in the phone, if you are not stored in the phone, if you are not have a phone. Just click on the number in the history and select the lock option.Whether the blacklist settings will reset when you update MIUI? Usually, when updating the system through OTA (But if you do a full reset to the factory settings (Hard Reset), the list of locked numbers will be cleared and you will have to re-create it. SMS If you only activated the call locking, SMS They can come. To stop them, you need to use the Security app» -> «Antispam: Enable the blocking as well SMS from this subscriber or from all unknowns.