Spam calls and messages from unknown numbers have become a scourge of modern times. According to Kaspersky, in 2023, one in three smartphone users experienced fraudulent calls at least once a week. Xiaomi phone owners have several built-in tools to combat this problem, from basic MIUI features to advanced security options, but many users are unaware of their existence or use them inefficiently.
In this article, we will analyze all available ways to block unknown numbers on Xiaomi, Redmi and other devices. POCO — From standard settings to hidden features and third-party solutions, you'll learn how to weed out not only spam, but also swapped-numbered calls (spoofing), which are often used by scammers to disguise themselves as banks and government agencies. MIUI 12-14 Adapted to the latest security updates 2026 year-end.
1. Standard locking through the "Phone" - a quick way
The easiest method is to use the built-in features of the Phone app, which is suitable for blocking specific numbers after the first call or for adding numbers from a magazine to a blacklist.
To block the number:
- 📱 Open the Phone application and go to the Journal section
- 🔍 Find the number you want to block and click on it.
- ⚙️ In the menu that opens, select Block the number (or Blacklist on older versions). MIUI)
- ✅ Confirm the action in the window that appears
For mass blocking of unknown numbers:
- Get on the phone. → ⋮ (three-point) → Settings → Number locking
- Activate the option to Block Unknown Numbers
- Manually add numbers or ranges (e.g. +79xxxx to lock all Russian numbers)
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If calls continue to arrive after blocking, check the blacklist synchronization settings in Mi Account. Sometimes resetting the app cache Phone helps with crashes.
2. Advanced settings in "Security" (MIUI Security)
The Security app (or MIUI Security) offers more flexible tools for spam filtering, where you can set automatic rules for blocking keywords, geolocating numbers, and even behavioral patterns (such as repeated calls from different numbers).
How to set up:
- Open Security. → Protection against spam
- Turn on the call filter switch
- In the section Blocking Rules select: 🚫 Block all unknown numbers 📛 Block numbers with suspicious prefixes (the list is updated automatically) 🔄 Block repeat calls (if one number calls more than 3 times a day)
Exceptions
A feature of this method is the cloud-based spammer database that Xiaomi shares among all users, and if a number is flagged as fraudulent by at least 100 users, it is automatically added to your blacklist.
How does cloud filtering work in MIUI?
Blocking through “Messages" (SMS-filter)
Not only does spam come through calls, but also via SMS. MIUI has a separate messaging filter that works independently of call blocking, and its settings are hidden deeper, but provide an additional layer of protection.
Algorithm of settings:
- 📩 Open the Messages app
- 🔧 Click on three dots in the upper right corner → Settings → Spam protection
- 🔄 Enable options: Filter spam messages Block messages from unknown senders Mark suspicious links (phishing protection)
- 🗑️ In Spam Management, set up automatic deletion of messages older than 30 days.
Important: some banking and service SMS may be spammy. Check the Spam folder in the Messages app regularly to ensure you don't miss important notifications.
4.Using Truecaller and other third-party applications
If built-in MIUI tools aren’t enough, you can install specialized applications. Truecaller is the most popular solution with a database of more than 500 million numbers, but there are alternatives like Hiya or Kaspersky Who Calls.
Advantages of Truecaller:
- 🌍 Global database of spammers with user reviews
- 🔍 Identifying unfamiliar numbers in real time
- 📊 Call statistics (frequency, geolocation, type of spam)
- 🛡️ Integration with MIUI system-application
How to set up:
- Install Truecaller from Google Play
- Register (requires a phone number for verification)
- In the application settings, enable: Spam Block → Aggressive Show notifications about blocking Synchronization with contacts (optional)
Phone Settings → Applications → Truecaller
Install the latest version of the app |Give all permissions requested |Enable aggressive lock mode |Add important numbers to whitelist |Disable ad display in the settings-->
⚠️ Warning: Truecaller collects your contacts and calls to improve its database. If privacy is critical, use alternatives like Should I Answer? that work locally without sending data to servers.
5. Hidden MIUI functions: blocking by regular expressions
For advanced users, MIUI can create custom lock rules using regular expressions, allowing you to block entire ranges of numbers, numbers with specific patterns, or even calls at specific times of the day.
Examples of regular expressions to block:
| Purpose of blocking | Regular expression | Example |
|---|---|---|
| All numbers with +7 code | ^\+7\d{10}$ | +79123456789 |
| Numbers with repeating numbers (spam) | ^\+?\d{1,3}(\d)\1{2,}\d+$ | +79991112233 |
| Calls from 23:00 to 8:00 | ^(?!.(0[8-9]|1[0-9]|2[0-2]).).*$ | Any room at night |
| Numbers prefixed 900-999 | ^\+79[0-9]{2}\d{7}$ | +79001234567 |
How to use regular expressions:
- Open Security → Spam Protection → Blocking Rules → Add a rule
- Select the Castomy Rule
- In the Template field, enter a regular expression
- Specify action: Block or Redirect to voicemail
- Save the rule and test it on test numbers
If you frequently encounter calls on behalf of banks, add your bank’s official numbers to the whitelist in Security settings. Fraudsters often swap numbers disguised as support for Sber, Tinkoff or VTB.
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Create a separate group in your contacts called "Important Numbers" and add banks, operator and family support, and set an exception for this group in your lock settings.