Spontaneous calls from intrusive advertising agents, cold calls from bank operators, or simply unwanted communication with certain people are a problem that almost every smartphone owner faces. In the Xiaomi ecosystem, this issue is implemented at the system level, which allows you to effectively filter incoming calls without installing third-party software. Owners of devices based on MIUI shells or the new HyperOS have access to powerful built-in antivirus and security functionality, which is often ignored by users, although it works more stable and economical than third-party applications from Google Play.
The locking process can vary depending on the version of the Android operating system and the specific firmware modification installed on your device. However, the basic principles remain the same: the system allows you to create lists of prohibited contacts, block hidden numbers and use smart filters to weed out spam. It is critical to understand that locking at the system level occurs before the phone begins to emit a call, which ensures complete silence and no visual notifications on the screen. This is a fundamental difference from simple detector applications that can miss the first beep.
In this article, we will take a look at all the available methods of isolation from unwanted subscribers. We will look at standard tools, hidden engineering codes, and the nuances of working with contacts in different versions of the interface. Properly configuring these parameters will allow you to fully control who can contact you, turning your smartphone into a reliable communication tool, rather than a source of constant irritation.
Use of the built-in "Security" application
The most reliable and functional way to limit incoming calls is to use the regular Security app, which is preinstalled on all devices of the brand. This system component is deeply integrated into the shell and has higher telephony access rights than any third-party downloaders. To get started, you need to start the application, usually having a green shield icon, and find the “Block” or “Blacklist” section at the bottom of the screen or in the settings menu.
The interface of this section may vary slightly from one model to another, but the logic remains the same, so you can manually add specific numbers that can no longer reach you, and it offers a convenient option to add directly from the call log, which greatly speeds up the response to persistent callers, and then the number automatically enters the lock database.
- 🛡️ Open the Security app and go to the Locking section».
- ➕ Click the Add button (often marked plus) to manually enter the number.
- 📞 Select contact from your phone book or call history for quick lock.
- ⚙️ Configure notification settings so that the system does not show missed calls from blocked.
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Enable the option to “Block Hidden Numbers” in the blacklist settings to cut off calls from those who hide their subscriber ID.
Importantly, the blacklist functionality doesn't just reset a call, it can ignore it completely, even leaving a log entry if the appropriate setting is activated, it keeps the call history clean, and it regularly updates its spam databases through cloud services, if you gave permission to do so when you first set up the phone.
Blocking directly through the “Phone” application
An alternative and often faster method is to use a standard caller interface, ideal when you need to urgently block a number that is trying to reach you right now or has just completed a call. In the Phone app (usually a blue or green phone icon), access to lock settings is implemented through the context menu of a particular contact or call.
To use this method, open a call log or contact list. Find the number you want, click on it and hold your finger (or click on the "i" icon or three dots in the corner) to call the action menu. In the option list that opens, you must select "Block" or "Add to the blacklist." The system will instantly apply a filter for this subscriber.
☑️ Checking the lock settings
Note that in some versions of MIUI, menus may offer additional options, such as blocking all incoming numbers from unknown numbers or creating rules for certain prefixes, which is especially useful for combating robot callers who change the last digit of the number every time they call.
Configure rules and filters for contact groups
Advanced users will appreciate the ability to create flexible filtering rules that go beyond simply banning a single number, allowing you to block entire groups of contacts or numbers not stored in your phone book, a powerful tool for those who want to communicate only with a trusted circle of people.
In the locker settings menu, you can find options that allow you to block calls from everyone except the contacts from your notebook, a radical but effective method that is often used during periods of increased activity of scammers, and blocking keywords in SMS is also available, which saves from spam mailings.
| Type of filter | Description of action | Effectiveness against spam |
|---|---|---|
| Blacklist | Blocking specific, manually entered numbers | High (for known spammers) |
| Hidden numbers | Automatic call screening without a determinant | Medium (may miss important calls) |
| Not contacts. | Blocking anyone not in the phone book | Maximum (requires caution) |
| Keywords | Filtering SMS on the content of the message | High (for text spam) |
When setting up hard filters such as “Block All Unknowns,” you need to exercise caution, and you may miss an important call from a courier, doctor, or emergency services officer if their number is not stored in your contacts, so a whitelist or temporary shutdown of the filter in critical situations becomes necessary.
Hidden codes and engineering settings
For users who prefer deep system configuration, special USSD-They allow you to control forwarding and locking at the operator level or basic modem settings, but using these commands requires accuracy, because erroneous input can change the behavior of the phone.
One of the most commonly used commands is to activate unconditional forwarding to a non-existent number or voicemail number, which effectively blocks incoming ones. But a more correct way is to use service management codes. For example, code ##4636## opens a test menu where you can find additional network management options in the Phone Information section, although direct locking of numbers is rare and depends on the processor model.
⚠️ Note: Using engineering codes such as ##4636## or other service combinations can cause network settings to reset. Do not change settings that you do not know the value of, especially under "Radio Info».
A safer and more effective “secret” tool is to activate numbering services through call settings. Settings –> Apps –> App settings –> Phone –> Locking incoming calls sometimes hide additional switches that are not displayed on the home screen of security settings in some regional firmware versions.
What if the code doesn't work?
Lockdown SMS-messages and junk content
A sound call is not the only source of irritation. SMS-Spam containing credit offers or links to phishing sites poses a real security threat. Xiaomi’s built-in filtering mechanism is able to analyze the content of messages and block them before they reach the inbox».
To activate this feature, you need to go to the Messages app, click on the menu icon (three dots or gears) and select Spam filter settings or Antispam. Here you can enable automatic blocking of messages containing keywords such as “credit”, “winning”, “card” and others characteristic of scammers.
- 🔍 Activate the Smart Filter so that the system can learn to recognize spam.
- 📝 Add your keywords to the list of filters that are forbidden to personalize.
- 🚫 Turn on displaying blocked messages in a separate folder to check their contents if necessary.
It is important to check the spam folder periodically, as automation sometimes makes mistakes and may miss an important notification from the bank or delivery service, considering it template. Regular "training" the system by marking false positives helps improve the quality of filtering in the future.
Third-party applications and their integration
Despite the power of the built-in tools, some users prefer to install specialized applications such as Truecaller, Kaspersky Who Calls or GetContact, which use crowdsourcing (data from millions of users) to identify numbers that have not yet been included in official spam databases.
When you install this app, Android will ask for permission to manage calls and access contacts. Once you grant permission, a third-party blocker can completely take over the management of incoming calls, which gives you the advantage of a huge number base, but also has the downside of increased resource consumption and data privacy issues.
⚠️ Note: When installing third-party number detectors, you transfer your contact database to the application developer's servers.
If you choose to use a third-party solution, make sure you disable the built-in MIUI blocker to avoid conflicts.Two systems trying to handle an incoming call at the same time can cause the phone to stop ringing altogether or malfunction, skipping important calls.
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The optimal defense strategy is to use a built-in blacklist for known numbers and connect a cloud-based anti-terror database (for example, through built-in MIUI services), without installing heavy third-party applications.