Spam calls and annoying offers from banks or scammers have become a real scourge of our time. Every day, the smartphone screen lights up from an incoming call with an unfamiliar digital code, interrupting work or rest. For Android users, there are several effective ways to solve this problem once and for all, without resorting to complex technical tricks.
In this article we will examine in detail the built-in functions of the operating system, the capabilities of applications from mobile operators and specialized software. You'll learn how to create a "digital shield" that will allow only important calls from contacts in your address book through. This will allow you to control your communication space.
Built-in blocking function in Android settings
Modern versions of the operating system Android equipped with a powerful call filtering tool right out of the box. You don’t have to install third-party software if your goal is simply to cut off anonymous callers. The mechanism of operation of this function is extremely simple: the system checks the incoming number with your phone book.
If the number is not saved in contacts, the call is either immediately dropped or sent to an answering machine without making a sound signal. Activation of this option may vary slightly depending on the manufacturer's shell (Samsung One UI, Xiaomi MIUI, Stock Android), but the logic remains the same.
To find the desired setting, open the standard "Phone" application and go to the menu, which is usually indicated by three dots in the corner of the screen. Next, select Settings and find the section Blocking numbers. Here you will see a switch called "Block unknown" or "Block hidden numbers".
⚠️ Attention: Enabling this feature may cause you to miss an important call from a courier, doctor or employer who is calling from a new work number, not yet saved in your contacts.
Using system tools is the most energy-efficient method of protection, as it does not require the running of background processes of third-party applications. However, it is worth remembering that this protection will not work if the attacker replaces the number with an existing one, but someone else's.
Before enabling total blocking of unknown numbers, create a separate contact group "Important" or "Work" so as not to lose contact with new business partners.
Using a blacklist through operator applications
Large mobile operators understand the scale of the spam problem and offer their own solutions for subscribers. These services often operate at the network level, meaning the call is blocked before it even reaches your smartphone. This is especially useful for combating robocallers.
The Antispam service is usually provided on a paid basis, but many providers include a basic version in their tariff plans. The connection is made through the operator’s personal application or USSD command. For example, for some operators, activation occurs through the command *110*771#, but it is better to check the exact codes on the official website.
The advantage of a network filter is that it has a huge database of fraudulent numbers, which is updated in real time by the collective efforts of millions of users. If someone in the country complains about a number, it instantly gets blacklisted for all subscribers of this operator.
- 📱 MTS: The "Black List" service allows you to add numbers manually or automatically block hidden calls.
- 📱 MegaFon: The "Antispam" service identifies unwanted calls and marks them in the log, preventing the phone from ringing.
- 📱 Beeline: The spam blocking function works based on the database and user settings in the personal account.
- 📱 Tele2: Offers the option of blocking unwanted calls with the ability to configure categories (for example, only advertising).
It is important to note that such services may have restrictions on the number of numbers in the blacklist in the free version. Advanced features, such as detailed reasons for blocking or statistics, may require a monthly subscription fee.
Third-party applications for filtering calls
If the built-in tools are not enough, specialized applications from the store come to the rescue. Google Play. The leaders in this niche are Kaspersky Who Calls, Yandex.Caller Identifier and Truecaller. These apps use cloud databases to identify the caller.
The principle of their operation is to compare the incoming number with a giant library of tagged users. If the number belongs to collectors, delivery services or scammers, the application will show this on the screen before you pick up the phone, or will automatically drop the call.
Installation of such software requires extensive permissions, including access to contacts and call logs. This is necessary for the correct operation of the number identification function and replenishment of the general database. Without these rights, the application will be useless.
| Application | Database type | Paid version | Features |
|---|---|---|---|
| Kaspersky Who Calls | Local + Cloud | Yes (extended) | High reliability, virus protection |
| Yandex.Identifier | Cloud (RF) | Yes (Premium) | Best identification of local organizations |
| Truecaller | Global | Yes (Gold) | Huge world database, search by name |
| NumBuster | Social | Yes | User reviews of the rooms |
It is worth considering that some free versions of such applications may display advertising. In addition, transferring data about your contacts to the service cloud raises questions about privacy for some users, so the choice should be informed.
Why do applications request access to contacts?
Access to the phone book is needed so that the application can check incoming numbers not only with its database, but also with your personal records, as well as to be able to upload contacts to the cloud to improve the overall database (if you agree to the terms).
Do Not Disturb mode as a radical measure
When spam becomes unbearable, you can use the mode "Do not disturb". This is a system function that silences all notifications and calls, except those included in exceptions. This is ideal for night time or important meetings.
Unlike a simple blacklist, this mode operates globally. You can set it up so that the phone only responds to repeated calls from the same caller within a few minutes. This is insurance in case of a real emergency.
To activate, go to Settings → Sound and vibration → Do not disturb. In the Calls and messages section, select the parameter Allow calls and set the value Only contacts. Now any number that is not in your address book will not be able to reach you.
⚠️ Attention: When activating Do Not Disturb mode, check your alarm settings. In some older versions of Android, system alarms could turn off along with the sound, although this has been fixed in modern versions.
This method is good for its versatility, but it requires discipline. If you forget to turn off mode after a meeting, you risk missing all the important calls for the day. It is recommended to use automatic rules according to the schedule.
☑️ Setting up the silent mode
Blocking hidden numbers via USSD codes
A separate category of spammers uses technology CLI (Calling Line Identification) to hide their number. In this case, “Unknown number” or “Hidden number” is displayed on the phone screen. Standard blocking by contacts will not work here, since there is nothing to compare with.
To combat such calls, special USSD codes provided by the telecom operator are often used. These commands send a request to the network with the requirement to reject any calls where the subscriber ID is missing.
There is no universal code for all operators, as it depends on the equipment and network settings in a particular region. However, the most common combinations include #31# to hide your number or special service codes to block incoming anonymous people.
Try entering the command *31*10# or similar, suggested in your operator's help. If the command is accepted, you will receive a confirmation message. You can usually check the status of the service through your personal account on the operator’s website.
It should be understood that blocking hidden numbers at the network level may conflict with legal services that hide their numbers for security reasons (for example, some emergency services or bank hotlines for call back).
Blocking hidden numbers via USSD works most reliably, since the cutoff occurs on the cell tower side, without putting a strain on your smartphone's battery.
Moving numbers to the blacklist manually
Sometimes automatic filters miss annoying callers, and you have to act manually. Call log in Android allows you to quickly add a specific number to the blacklist directly from the call history.
Open the Phone application and go to the tab Recent. Find the number you want to block and click on it to reveal more details. In the menu that appears, select Block/Send spam.
After confirmation, the number is added to the list of ignored ones. The system will automatically drop calls from this contact. You can also add a comment to a blocked number so that after a while you remember who it was.
To view and manage the list of blocked subscribers, return to Settings → Blocking numbers. Here you can remove numbers from the blacklist if you change your mind, or add new ones manually by entering them from the keyboard.
This method is effective against specific stalkers or collectors, but is useless against mass robocalls, where numbers change every second. Therefore, it is better to combine manual blocking with automatic filters.
What happens to SMS from a blocked number?
In most Android versions, messages from blocked numbers are not deleted, but are hidden in a separate "Spam" folder or simply do not receive a notification about them, but they are saved in the device memory.
Frequently asked questions (FAQ)
Will the caller see that he is blocked?
Usually the subscriber does not receive any special notification about blocking. For him, the call just takes a long time and then drops or goes to voicemail. He may think that you are not picking up the phone or picking up the phone outside the network coverage area.
Is it possible to block a number starting with certain numbers?
You cannot block a mask of numbers (for example, all numbers +7999...) using standard Android tools. This requires advanced third-party applications that support blocking by mask, or a service from a telecom operator.
Does blocking numbers affect the speed of the phone?
Built-in blocking has virtually no effect on performance. Third-party apps may consume additional battery power and RAM as they constantly analyze every incoming call in real time.
What to do if an important call from a doctor ends up in spam?
Regularly check your blocked call log or Spam folder in your Caller ID app. If you are waiting for an important call, temporarily disable filtering or add the institution number to your contacts in advance.
Does blocking work if the phone is turned off?
No, if the phone is turned off or is in airplane mode, blocking on the device does not work. However, operator network services (Antispam) can work even when the phone is turned off, since filtering occurs on the operator’s equipment.