How to block SMS on Xiaomi 12: the full guide

Owners of modern Xiaomi smartphones, including the flagship model Xiaomi 12, often face intrusive advertising and spam mailings that can come at any time of the day. Effective blocking of unwanted messages becomes not just a convenience, but a necessity to preserve productivity and data privacy. The built-in tools of the MIUI 14 shell and the Android operating system offer powerful protection mechanisms that are often underestimated by users.

In this article, we will take a look at all the available ways to isolate information noise, from standard message settings to advanced filtering scenarios. You will learn how to block SMS from specific senders, how to hide the content of notifications from prying eyes and what hidden features can help in the fight against aggressive marketing.

Using the built-in spam filter in the Messages app

The first and most effective step is to activate the built-in filter, which is based on cloud databases and local text analysis algorithms. Xiaomi automatically checks incoming messages for signs of fraud or advertising mailings, placing them in a special folder without disturbing the user with an audible signal. To access these settings, you need to open the standard Message application and go to the settings menu through three points in the upper corner.

In the Antispam or Spam Filter section (the name may vary depending on the regional firmware), you will find a security activation switch. Turn on this feature so that the system starts automatically scanning incoming traffic. The algorithm analyzes not only the sender number, but also the content of the text, identifying suspicious links and template phrases characteristic of scammers.

It is important to check Spam periodically, as important messages, such as confirmation codes from banks or delivery services, can also be sent there if they have been misclassified. In filtering settings, you can also add specific keywords that are guaranteed to block the message, which is especially useful for combating mailings from local stores or services using certain stable expressions.

⚠️ Warning: Turning on the filter may cause some promotional mailings from legitimate companies (such as loyalty bonuses) to be hidden, so check your spam folder regularly.

Blocking specific numbers and contacts

If you are concerned about a particular subscriber or a short number from which spam comes, the most radical and effective method is to block the contact completely. Unlike keyword filtering, this method ensures that you do not receive any data from that source at all, including calls, if you also block them in the phone book.

To implement this method, open a dialog with an unwanted sender. Click on the three dots in the upper right corner of the screen or the contact avatar to open the action menu. In the list of options, select Block or Blacklist. Once validated, all future attempts to communicate from this number will be interrupted at the system level.

• 📵 Open a dialogue with the sender of spam in the Messages app.
• 🔒 Click on the menu (three dots) and select the lock option.
• 🗑️ Confirm the addition of the number to the blacklist of the system.
• ✅ Check the list of blocked in the settings to make sure you are successful.

It is also possible to block not only individual numbers, but entire groups, such as all hidden numbers or unknown contacts not stored in your phone book, which is especially relevant during periods of high activity of phone scammers. However, be careful: enabling locking all unknown numbers can lead to missing important calls from couriers or taxi services that use dynamic numbers.

Configures to hide the contents of notifications on the lock screen

Often the problem is not the fact of receiving SMS, but that confidential information is displayed on the lock screen, becoming accessible to prying eyes. AMOLED-The screen always shows notifications, which are convenient but not safe in places. To solve this problem, you need to configure the content of the notifications.

Go to the system settings of your smartphone, then select the Notifications and Status section. Find the Notification Format or Display on the lock screen. Here you are asked to choose the option to Hide Content. Once you activate this option on the locked screen, you will only see the name of the application (such as "Messages") and the number of new events, but the text of the message itself will remain hidden until the device is unlocked with a biometric or pin code.

This is a critical setup to protect the two-factor authentication codes that often come in SMS. If an attacker gains physical access to your unlocked phone, this setup won’t help, but it does protect against “shoulder-over-the-shoulder” in a transport or office.

Use of forwarding codes and third-party applications

In some cases, embedded funds MIUI This may not be enough, especially if spam comes from different short numbers or through Internet services (iMessage on Android there are no analogues, but there are some spam messages). RCS-In such situations, specialized applications from Google Play, such as Should I Answer? or Sms Blocker, come to the rescue. These applications require the provision of extended permissions to read SMS, which is normal for their functioning.

Another technical but effective method is to use operator forwarding codes. You can redirect all SMS to another number (for example, the old one you don't use), but this method has limitations and depends on the tariff plan. A more reliable way within a smartphone is to turn off the RCS service (Chat features), if spam comes through extended messages.

• 📥 Install a proven blocking app from Google Play.
• 🔐 Provide the necessary permissions to access SMS and calls.
• ⚙️ Set up in-app filtering rules (by keywords or regions).
• 📶 If necessary, turn off the chat function (RCS) in the settings of Google Messages.

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Use open source applications to block if you are concerned about data privacy, as they do not pass the content of your messages to third-party servers for analysis.

When installing third-party blockers, pay attention to reviews and installs. Don’t trust little-known applications to access your personal correspondence, as this can lead to data leakage.

Block notifications from specific applications and services

Often, SMS-like notifications do not come through a standard message application, but through messengers or banking applications that use push notifications masquerading as SMS. To block them, you need to manage permissions at the Android level. Go to Settings → Apps → All applications.

Find an app that abuses notifications (such as a store, bank, or delivery app). Go to Notifications. Here you will see a detailed list of notification types. You can turn off all notifications completely or, more correctly, leave only critical ones (such as "Transactions" or "Security"), and advertising categories ("Promotions", "News", "Tips") turn into a status No Sound or completely disable.

This technique allows you to fine-tune the information flow, leaving important communication and removing visual noise. Xiaomi 12 also operates the function "Important notifications", which allows you to display on the lock screen only messages from favorite contacts, ignoring all other applications.

Advanced DND settings (Do not disturb)

MIUI’s Do Not Disturb mode has flexible settings that allow you to create schedules to block any sounds and vibrations, including SMS. You can set it to automatically turn on at night or during business hours. Go to Settings → Sound and vibration → Do not disturb.

Inside the mode menu, you can create a schedule, for example, from 23:00 to 07:00. During this time, the phone will ignore incoming messages. However, to avoid missing an emergency call, set exceptions: allow repeated calls (if the same person calls twice within 5 minutes, the call will pass) and calls from favorite contacts. SMS in this mode usually just do not emit sound and do not vibrate, remaining in the notification curtain.

⚠️ Warning: Make sure that the Do Not Disturb settings do not tick off all visual notifications if you want to see missed messages after the mode ends.

Using this mode is the best way to ensure that you have uninterrupted sleep or focus on work, knowing that spam mailings will not distract you with audio signals. It is a software-based perceptual lock that does not delete messages, but makes their presence invisible until you decide to look at the phone.

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Combining the built-in spam filter, blacklist and schedule-based "Do Not Disturb" mode gives 100% protection against unwanted information noise on the Xiaomi 12.

Comparison of blocking methods

The best method depends on your specific situation: whether you are struggling with one persistent number or with a massive attack of advertising SMS gateways. Below is a comparison table that will help determine the strategy of protecting your Xiaomi 12.

Remember that no method is 100% perfect, so a combination of approaches is recommended, such as the MIUI filter enabled plus a manual blacklist for particularly intrusive numbers, which is a great result without the need to install additional software.

Frequently Asked Questions (FAQ)