Constant calls from intrusive advertisers, bank agents and scammers make the smartphone a source of stress. Owners of Xiaomi and Redmi devices often find that standard filtering methods miss too much noise. MIUI has powerful built-in functionality that allows you to completely isolate the user from unwanted contacts without installing third-party applications.
Effective locking requires a comprehensive approach, because simply turning on one button is not enough to protect one hundred percent. You need to properly configure the built-in number detector, activate the Do Not Disturb mode and, in extreme cases, use the function of completely ignoring all hidden subscribers. Below we will discuss all the available methods, from soft filtering to hard cut-off.
Use of the built-in MIUI blocker
The first and most logical step is to activate native security tools that are already built into the HyperOS or MIUI shell. The system offers flexible settings to filter incoming ones, allowing you to create exception lists and rules. To access this functionality, you need to open the Security application, which is the system control center.
Inside the app, find the Lock or Antispam section, which hides the main levers of incoming traffic control. In the Xiaomi ecosystem, antispam is based on updated databases, which allows you to automatically identify and flag suspicious numbers. However, for complete silence, you need to manually adjust the rules.
From the lock menu, select Settings (usually the gear icon or three dots in the corner). You will need the Call Lock section. This is where you activate the Block Unknown Numbers switch, which works by comparing the incoming call to your phone book.
If the number is not in the contacts, the call will be automatically reset and the caller will hear the signal is busy, which is the most effective method for those who wait for calls only from saved people.
It is worth noting that the settings may vary slightly depending on the firmware version. In some regions, the feature block is transferred directly to the Phone application. To do this, click on three dots in the dial corner and select Settings → Lock inbox.
⚠️ Warning: Activating hard locking of unknown numbers can cause you to miss important calls, such as from couriers, doctors or delivery services that call from city or mobile numbers not stored in your memory.
It is recommended to check your call history to make sure that important numbers are actually saved in the address book, and it is also worth remembering that hidden numbers (those defined as "Unknown" or "Hidden Number") often pass through standard filters, so they need separate settings for them.
Setting up the "Do Not Disturb" mode
If you want temporary silence or a more flexible approach than full lockdown, use Do Not Disturb (DND) mode. This tool allows you to skip calls only from selected contacts, ignoring everyone else. Unlike full lockdown, here you create a whitelist yourself.
To activate, go to Settings → Sound and Vibration → Do Not Disturb. Turn on Mode and click on Schedule or Allow Calls. Choose Favourite Only or Contact Only. Now any calls from numbers that aren't in your phone book will not emit sound or vibration, and the screen may not even light up.
The advantage of this method is that it's flexible, you can set it up automatically at night or during meetings using a calendar, and you can set the system interrupts to make sure that you get a call from the same number for 3-5 minutes, and that's a good thing in an emergency.
☑️ Setting up the silence mode
It is important to distinguish between full lock and DND. In the first case, the subscriber immediately hears the knockout beeps; in the second, he has a beep, but your phone is silent. For the subscriber, the difference is noticeable, for you, the result is similar (you are not responding).
Remember to add the "Repeat Call" feature to the exceptions if you're afraid to miss the real urgency. The logic is simple: if a person calls twice in a row at intervals of less than 5 minutes, the system considers the call important and skips it, even if the number is not saved.
Blocking of hidden and unknown numbers
Special attention should be paid to calls where the subscriber specifically hides his ID. On Xiaomi, this is fought through special switches in the lock menu. Return to the Security application → Lock → Settings.
Find Hidden Numbers Block, and activating this option ensures that calls that come without a number (No Caller ID) are interrupted at the network or modem level, which is critical to protecting against some types of fraud.
It is also possible to block all international calls if you are not waiting for calls from abroad, and this is done through the same interface, which helps reduce the amount of spam from overseas call centers.
| Type of number | Locking method | Efficiency |
|---|---|---|
| Number on the blacklist | Addition to contacts or history | 100% |
| Unknown (no contact) | Setting up "Block Unknowns" | 95% |
| Hidden number (No ID) | Switch "Block Hidden" | 100% |
| International spam | Blocking foreign codes | Tall. |
After making changes, be sure to check the filters by asking someone to call you from a number that is not in the contacts. make sure the call doesn't go through or goes silently, depending on the method chosen.
What does the caller see when they lock?
Third-party applications for numbering
The regular tools are good, but the carrier databases are often updated more slowly than new spammer numbers are available, and specialized applications like Yandex, Kaspersky Who Calls, or GetContact come to the rescue, and they work in conjunction with the system blocker.
Once installed, it will request permission to manage calls, so that the application can pick up an incoming call, check the number with the cloud database and, if necessary, reset it automatically, and the databases of such services are replenished by the users themselves.
Integration with Xiaomi often requires manually allowing auto-start and work in the background. Go to Settings → Apps → Find your garbage collector → Auto-run (enable) and Battery Saving (select "No Limits"). Without this, Android can "kill" the protection process for the sake of energy savings.
⚠️ Note: By installing third-party number detectors, you agree to transfer your data (contact book) to the developer's servers for database reconciliation.
Using third-party solutions is particularly effective against organizations that change numbers frequently, with statistics showing that such apps block up to 98% of advertising calls that a standard filter skips.
💡
Tip: For maximum efficiency, combine methods. Leave the unknown lock on MIUI, and use the third-party application only as a database to determine the name of the caller, without giving him the right to drop the call.
Services of telecom operators as an additional barrier
And remember, you can filter before the signal reaches your smartphone, and the big carriers (MTS, Beeline, MegaFon, Tele2) offer antispam services. They work on the network side.
By connecting such a service (often paid or share-free), you get SMS-Notification of spam instead of the call itself. The phone doesn't ring at all. It's ideal for those who want complete silence and don't want to load the smartphone processor with unnecessary apps.
For activation, it is usually enough to send USSD-For example, MegaFon has an anti-spam service, MTS has a spam protection service. Check the current commands in your personal account.
The advantage of network locking is that it doesn't consume the phone's battery and works even when the device is turned off (the call just won't arrive), but it can be paid after the trial period.
Problem Solving and Frequent Errors
Users often encounter situations where settings seem to be enabled, but calls still pass. Most often, the problem is permissions or version conflicts. Make sure the Security and Phone app have all the necessary permissions in the Settings menu. → Annexes.
Another common mistake is having two calling apps: Xiaomi can have Google Phone and a standard MIUI Dialer installed; lock settings must be checked in the default application for making calls; you can switch between them to Settings → Applications → Default Apps.
If you use Google Phone, the way is different: open the app, click three dots → Settings → Spam Protection. There you need to turn on Google filters, which also work perfectly in conjunction with Xiaomi hardware.
💡
Main conclusion: For 100% of the result, use the bundle: built-in MIUI blocker (for unknown) + network protection of the operator (for advertising) + Do not disturb mode (for sleep).
In rare cases, resetting calls helps, and it won't delete your contacts, but it will return all call parameters to factory values, and you can find this option in the settings menu of the Phone app at the bottom of the list.