Xiaomi MIUI-based smartphones offer built-in anti-spam tools, but standard locking of individual numbers is often not enough. If you are flooded with calls from numbers starting at +7999, 8-800-555 or other suspicious prefixes, manually adding each to the blacklist will take hours. Fortunately, MIUI has a hidden number mask lock feature – it allows you to block all calls from a certain prefix (for example, +37529* or 8495**).
In this article, you will learn how to blacklist a prefix on Xiaomi, Redmi or POCO, what limitations the method has, and what to do if the feature suddenly stopped working after the update. We will also explore alternative ways – from third-party applications to operator settings that will help get rid of intrusive call centers and scammers.
⚠️ Note: Prefix locking may affect legitimate numbers (e.g., bank or delivery services) before setting up, check if organizations that are important to you use similar combinations.
Why a standard blacklist doesn’t save you from spam
Built-in blacklist in MIUI It is convenient for blocking specific numbers, but useless against mass mailings. Spam call centers use hundreds of disposable numbers with the same prefix (for example, for example, the use of a single number, +7910123* or 8499321), and add them one by one, Sisyphus labor, +7495 for Moscow or +7812** for St. Petersburg).
The main problems of the standard blacklist:
Solution – a masked number lock that allows you to ban all calls from a certain prefix (for example, +375* for Belarusian scammers or 8800555**** for intrusive mailings. MIUI It is hidden in the engineering menu, and in others it requires the use of the ADB-team.
How to Add a Prefix to a Blacklist with MIUI Settings
On most Xiaomi, Redmi and POCO smartphones with MIUI 12-14, prefix locking is available via the standard menu, but the path to it depends on the firmware version. Below is a universal instruction for modern devices (2020-2026 release).
Step 1. Open the Phone app (tube icon) and go to Recent (or Call Log) section.
Step 2. Slip on the three dots in the top right corner and select Settings → Lock numbers (or Blacklist).
Step 3. Turn on the Unknown Number Lock switch (this will block all calls from hidden numbers) and scroll down to Add Prefix or Mask Lock. If there is no such item, proceed to the ADB method.
Step 4: Enter the prefix you want to block using the * (star) symbol as a stand-up sign.
- 📱 +7999* – Blocks all megaphone prefix numbers +7999.
⚠️ Note: Some prefixes (e.g, +7495 for Moscow) may belong to legitimate organizations. Before blocking, check the number through a service like Zvonilka.ru or Nomer.org.
Make sure the prefix is not used by banks or delivery services|
Check the reviews of the room on the Internet |
Add exceptions for important contacts |
Keep a backup copy of the blacklist-->
Blocking the prefix via ADB (for advanced users)
If your version of MIUI does not have a mask lock option, you can activate it via ADB (Android Debug Bridge), which works on most Xiaomi devices, but requires a computer connection and basic command line knowledge.
What you need:
- 🖥️ Computer with installed Xiaomi and ADB-tools drivers.
- 📱 Included Debugging by USB on a smartphone (path: Settings) → The phone. → Version. MIUI → 7 times tap the assembly number → return to → For developers → Debugging by USB).
- 🔌 USB-cable (preferably original).
Instructions:
- Enter the command to add the prefix to the blacklist (replace) +7999 Prefixed: Adb shell content insert --uri content://call_log/calls/blacklist --bind number:s:"+7999" --bind type:i:3 Here. type:i:3 means blocking incoming calls.
⚠️ Attention: Misuse of the right ADB It can cause your phone to crash, and if you're not sure what you're doing, use third-party apps.
What if the ADB can’t see the device?
Third-party applications for blocking prefixes
If the built-in MIUI tools fail, you can use third-party apps, which offer advanced features like blocking regular expressions, cloud-based spam numbers, and even automatically adding new prefixes from community blacklists.
Top.-3 prefix-blocking applications:
| Annex | Features | Cons |
|---|---|---|
| Easy Blacklist | Mask blocking (+7999*), import/export lists, no advertising. | Paid (≈150₽), requires permission to call. |
| Calls Blacklist | Support for regular expressions, SMS blocking, log of blocked calls. | The interface is overloaded, advertising in the free version. |
| WhoCalls | Cloud-based spam numbers, automatic prefix updates. | Registration is required, sometimes by mistake blocking legitimate numbers. |
💡 Tip: Before installing, check the permissions of the app. If it requests access to contacts, SMS geolocation without an obvious reason – it is better to refuse.
Built-in blacklist MIUI|
Easy Blacklist|
Calls Blacklist|
WhoCalls|
Other (I will write in the comments)-->
How to block prefixes through operator settings
Many mobile operators offer their own spam-fighting services, which are less flexible than apps, but do not require software installation and operate at the network level.
The methods of blocking from popular operators:
⚠️ Warning: Operators can only block incoming calls to your number if the spammer calls through your phone. IP-Telephony (such as WhatsApp or Skype) will not work.
What to do if the prefix locking doesn’t work
Sometimes the added prefix is ignored by the system.
Problem 1: The prefix is not blocked after adding.
- 📋 Check the prefix format: it must be in an international format (e.g., in a prefix format, +7999, not 8999).
Problem 2: Legitimate numbers are blocked.
- ✏️ Refine the prefix: for example, instead of +7495* (all Moscow numbers) use +7495123* (specific range).
Problem 3: The mask lock function disappeared after the update.
V MIUI 14 and newer Xiaomi removed the prefix locking option from the standard interface. ADB-method.
💡
If the spammer calls from different prefixes, but from the same region (for example, +7343 for Yekaterinburg), add the entire regional code to the blacklist: +7343*.
Additional protection measures against spam calls
Blocking prefixes is an effective, but not the only, way to fight spam. Here's what else you can do:
1. Set up "Do Not Disturb" for unknown numbers:
Go to Settings → Sounds and Vibrations → Do Not Disturb → Allow exceptions and disable Calls from unknown numbers. Now all unfamiliar subscribers will be sent to voicemail.
2. Use cloud spam databases:
Apps like Truecaller or GetContact automatically detect spam numbers from a user database, and they require access to your contacts.
3. Register in the register "Do not call":
In Russia, the service Netcalling.ru, where you can add your number to operators and call centers will stop calling you, the effect is not instantaneous (up to 30 days), but reduces the amount of spam.
4.Block it. SMS-spam:
In Settings → Applications → Messages → Spam protection, enable SMS filtering. This will help get rid of advertising mailings that often accompany spam calls.
💡
The combination of prefix blocking + cloud-based spam numbers (like Truecaller) + Do Not Disturb setting gives maximum protection against intrusive calls.