In today's digital world, the phone has become not just a means of communication, but a central hub through which financial and personal information passes. For subscribers of the operator Tele2, as well as for users of other networks, intrusive spam and calls from unknown numbers remain an urgent problem. Fraudsters are constantly improving social engineering methods, trying to lure out confidential data or simply impose paid services. That is why the ability to effectively block unwanted calls is becoming a critical skill for every smartphone owner.
There are several levels of protection: from the built-in functions of the operating system Android to specialized services of the operator itself. Each method has its own characteristics, advantages and limitations that must be taken into account to achieve maximum results. In this article, we will analyze in detail all the available methods so that you can choose the most suitable one for your situation and device model.
It is important to understand that the standard settings may differ depending on the firmware version and the manufacturer's shell. However, the basic principles of blockers remain similar on most devices. We will consider universal solutions that are suitable for both pure Androidand for shells MIUI, OneUI or ColorOS.
Blocking through Android settings
The fastest and most reliable way to limit the access of unwanted subscribers is to use the built-in functionality of your smartphone. The operating system Android has been equipped for several years with powerful call filtering tools that do not require the installation of third-party software. To get started, just open the standard “Phone” application and go to the settings menu, usually indicated by three dots or a gear.
In the menu that opens, you need to find the section related to blocking numbers. Depending on the version of the operating system, this item may be called “Number blocking”, “Black list” or located inside the “Antispam” section. Here you will find a switch to activate the “Block unknown numbers” feature. Important: Enabling this option will cause calls to be rejected automatically if the caller's number is not saved in your phone book.
⚠️ Attention: When you activate the complete blocking of unknown numbers, you risk missing an important call from a courier, doctor or colleague, whose number is not yet recorded in contacts. Use this function with caution.
Additionally, the system allows you to create individual lists of prohibitions. You can manually add the specific number that bothers you most often. To do this, in the blocking menu, select the option to add a number and enter the nine-digit subscriber code or select it from the call history. This action is irreversible without manual removal from the listso carefully check the entered data.
Some smartphone manufacturers implement their own spam detection algorithms that work at the database level. For example, devices Xiaomi or Samsung can mark probable spam in red before you even pick up the phone. Regularly update the database of spam numbers in the settings of the Phone application so that the protection remains current.
Using USSD commands and Tele2 services
Operator Tele2 provides subscribers with their own tools to protect against unwanted communication. One of the easiest ways is to use USSD commands, which work even without Internet access. To activate the basic Black List service, you need to dial the command *155*8*1# and press the call button. This action will activate the service, after which you will be able to manage the list of blocked numbers.
To add a specific number to the black list through the USSD menu, use the format *155*8*3*number#, where instead of the word “number” the subscriber’s digits without the eight or plus are substituted. Removal occurs according to a similar principle using the appropriate code in the service menu. You can also manage the service through your personal account or the My Tele2 mobile application, which is often more convenient than visually entering commands.
- 📱 Command
*155*8*1#—activation of the “Black List” service. - 🚫 Command
*155*8*3*number#— adding a number to the blacklist. - ✅ Command
*155*8*4*number#— removing a number from the blacklist. - ℹ️ Command
*155*8*2#—checking the status of the service and the list.
You should remember that the “Black List” service from the operator is paid. Tariffing may depend on your current tariff plan, so before activation it is recommended to check the cost of connection and subscription fee. Typically, from blocked numbers, the subscriber does not receive notifications about missed calls, and the caller receives a busy signal or an unavailable message.
Blocker applications for Android
If standard tools are not enough, specialized applications from the store come to the rescue Google Play. Market leaders are solutions like Kaspersky Who Calls, Truecaller or Yandex.Blocker. These apps use huge cloud databases, updated in real time by thousands of users, which makes it possible to identify even new fraudulent numbers.
For such applications to work correctly, they must be given broad permissions. In particular, it requires access to the phone book, call history and, critically, the right to display on top of other windows. Without this, the application will not be able to intercept the incoming call and drop it before the phone starts ringing. After installation, be sure to go through the initial setup and synchronization of the databases.
☑️ Setting up the blocker
However, using third-party blockers has its own risks. Many of them operate on a freemium model, where advanced functionality is available only for money. In addition, some applications may transmit data about your contacts to their servers for analysis, which calls into question the confidentiality of personal information. Carefully read the user agreement before installation.
⚠️ Attention: Do not install blockers from unknown sources (APK files from forums). Such apps may contain malicious code that can steal passwords from banking applications.
Do Not Disturb mode as a temporary measure
In situations where complete peace is required, for example, during sleep or an important meeting, the Do Not Disturb mode is the optimal solution. Unlike the blacklist, this mode does not permanently block numbers, but temporarily limits sound and vibration notifications. You can configure it in the section Settings → Sound and vibration → Do not disturb.
The flexibility of this mode lies in the ability to create exceptions. You can set up the system so that repeat calls (when the same number rings a second time within 15 minutes) will still go through. You can also restrict calls only from selected contacts or contacts from certain groups, such as Family or Work. This ensures that you don't miss an emergency call while other spam is ignored.
Do Not Disturb mode automation eliminates the need for manual settings. The smartphone can independently turn on this mode according to a schedule (for example, from 23:00 to 07:00) or when connected to a specific Wi-Fi network. This is especially convenient for those who value daily routine and want to eliminate nighttime disturbances from promotional calls.
What is the difference between airplane mode and Do Not Disturb mode?
In airplane mode, the phone's radio module is completely turned off, and you become unavailable for all calls and SMS. In Do Not Disturb mode, communication works, calls and messages are received, but the phone does not make sounds or vibrate (except for configured exceptions).
Comparison of anti-spam protection methods
The choice of the optimal protection method depends on your individual needs and level of technical training. Below is a comparison table to help you decide which option is best for your situation. Each method has its own strengths and weaknesses.
| Method | Efficiency | Cost | Complexity of setup |
|---|---|---|---|
| Android settings | Medium (only hidden numbers) | Free | Low |
| Tele2 service | High (network level) | Paid (subscription fee) | Low |
| Applications (Truecaller) | Very high (cloud databases) | Freemium / Paid | Average |
| Do Not Disturb mode | Temporary (scheduled) | Free | Low |
Combining methods gives the best results. For example, using the built-in Android blocker in conjunction with a free version of the caller ID application can block most spam penetration channels. Operator services in this case can serve as additional insurance for the most persistent violators.
You should not rely on just one tool. Fraudsters are constantly changing tactics, using different numbers and technologies to bypass blocking (spoofing). Therefore, regular updating of databases and monitoring of security settings are a mandatory part of the digital hygiene of the modern user.
Ideal protection is built on a combination of built-in phone functions and cloud databases of third-party applications.
Frequently asked questions (FAQ)
Will the subscriber know that I have added it to black list?
When using the built-in Android tools, the caller usually hears a beep, and then a reset, or immediately a busy signal. The Tele2 operator, with the “Black List” service activated, can broadcast a voice message about the subscriber’s unavailability. The caller will not receive an exact notification that the number is blocked by you, but will understand this by the nature of the network response.
Is it possible to block a number that hides its identifier?
Yes, the “Block unknown/hidden numbers” function in the Android settings or the operator’s service is specifically designed for this. However, be careful: together with scammers, you can block calls from clinics, delivery services or important organizations that use corporate gateways with a hidden number.
Is the history of blocked calls saved?
In the standard Android call log, blocked calls may not be displayed at all, or may be marked with a special icon. Blocker applications usually keep a separate log where you can see the time and number of the blocked call. In the operator's details, calls from blocked numbers may be displayed as failed.
How to unblock a number if I accidentally added it to the blacklist?
To do this, you need to return to the menu where you blocked it. In the phone settings, this is the “Blocked numbers” section, where you need to click on the cross or the delete button next to the contact. If you used the Tele2 service, send a USSD command to delete or use the operator’s personal account.
Does a large number of blocked numbers affect the operation of the phone?
Modern smartphones can easily cope with thousands of entries in the blacklist. However, full phone memory (not the list, but the device itself) can slow down the system. Regularly clear call logs and delete old SMS to maintain the performance of the gadget at a high level.