Why SMS does not come to Xiaomi: reasons and solutions

When a long-awaited bank confirmation code or a message from a loved one doesn’t appear on Xiaomi’s screen, it can unsettle anyone. In the digital age, the lack of communication with the outside world is seen as a critical failure, especially if the phone is urgently needed to work or log in to services. Modern MIUI and HyperOS shells have powerful security tools that unfortunately sometimes work too hard to block legitimate messages or violate standard data protocols.

The problem of lack of incoming SMS-Messages on Redmi and Poco smartphones are complex, which can be due to both banal overflow of SIM card memory, and deep system conflicts of network settings or errors on the operator side. Users often find that notifications don’t come from specific senders, such as banking services, while private messages arrive without delay. Understanding the mechanics of how messages work on Android is the first step to successfully troubleshooting a problem.

Before you take a device to a service center or write angry feedback to an operator, it is worthwhile to conduct a self-diagnosis. In most cases (more than 80%), the problem is solved by changing one setting or rebooting the message service. It is critical to first check the balance status and network availability, as this is the most common but ignored cause of failures. Next, we will discuss in detail the algorithms of actions that will help return functionality to your device.

Network diagnostics and status SIM-map

The first thing to do when you don't have a connection is to make sure the physical integrity of the connection. Xiaomi smartphones are sensitive to the quality of the SIM card's contact with the tray contact group. If the device has recently fallen or been vibrated, the contact may have broken. Take out the tray, wipe the SIM card chip with soft cloth and paste back in before the characteristic click. Make sure the status bar displays the network icon (4G/LTE/5G) and there is no "Network" label.

One of the hidden reasons why SMS codes don't come is that the SIM card itself is overflowing with memory, and older cards have limited storage space for incoming messages. If the memory is full, the new messages simply cannot be written, and the operator returns them to the sender with a delivery error. To check this, open the message settings and look for the option "Save to the mail". SIM-map».

It's also worth checking if the Flight Mode or Do Not Disturb feature is activated.In the MIUI shell, Do Not Disturb mode can be set so aggressively that it hides not only the sound but also visual notifications of new messages. Check the notification curtain and make sure the aircraft icon is not on and the silence mode is turned off for incoming calls and messages.

• 📶 Check the signal level: if it is lower 1-2 Try moving to the area with the best coverage.
• 🔄 Reboot the device: this will force the phone to re-register in the operator’s network and update it IP-address.
• 💳 Check balance: A negative balance can block some types of messages, especially service messages.
• 📵 Make sure that SIM-card not blocked PIN-post-reboot.

⚠️ Note: If you use two of these SIM-Check which card is assigned to receive. SMS The settings are in the Settings menu. → SIM-Maps and mobile networks. Messages can come to the second card while you wait for them on the first card.

Messages and MIUI Optimization App settings

MIUI is known for its strict energy saving policy, which often kills background processes, including the messaging service. If the system decides that the Messages app is consuming too much resources or was not used recently, it can limit its background activity, which leads to delays or a complete stop of new emails coming in until the user opens the app.

To solve this problem, go to the advanced settings of the application. Go to Settings → Applications → All applications → Messages. Here you are interested in the Battery or Energy Saving section. Set the No Limits mode, which will allow the system to keep the process active all the time, which is critical for instant notification delivery.

Another important parameter is the availability of updates for the application itself. In the GetApps store or Google Play, patches can come out that fix compatibility bugs with specific versions of Android. It is also worth clearing the app cache if the problem occurred suddenly after the system update. Accumulated temporary files can cause conflicts in the operation of the communication module.

MIUI Optimization is a feature that can be in conflict with native messaging services in some cases (especially on global firmware) and disabling this option (available in the Developer Menu) can help, but keep in mind that it will change the interface of some system apps to the stock Android style.

SMS Center Settings Failure (SMSC)

One of the most technical and often overlooked reasons is incorrectly configuring the service center number (SMSC), which is the number that the operator routes all incoming and outgoing messages through. If the phone's settings down that number or change (for example, after flashing or changing the region), the phone will not physically be able to receive the message, even if the network catches perfectly.

You can check and change the message center number through the engineering menu or the standard dialing interface. Enter ##4636## (code may vary depending on the model and version of Android). In the menu that opens, select Phone Information and find the SMSC field. Your operator number should be listed here. If the field is empty or the number is incorrect, enter the current number for your region (it can be found on the operator's website) and click Update or Set.

For more advanced users, a method is available through ADB-If you connect the phone to the computer, you can send a command to reset the settings. SMS-It's the center to the operator's factory values. ADB and the debugging included USB.

adb shell service call sms 17 i32 0 i32 0 s16 "message center number"

When you change your SMSC settings, make sure you restart your device, and the changes only come into effect after you completely reboot the communication module, and if you send messages after that, then the problem was routing at the protocol level.

Blockers and spam filters

The antivirus and security module built into MIUI have powerful spam filtering algorithms that sometimes work too effectively and flag important messages from banks or government agencies as spam, removing them from the shared inbox, and the user thinks that the text hasn't arrived, and it's in quarantine.

To check this, open the Messages app and find the Spam and Lock folder (usually found in the three-dot menu or in the “More” section). If you find a lost message there, add the sender number to the whitelist. To do this, click on the message, select options and specify “Do not spam” or “Add exceptions.”

It’s also worth checking out third-party apps if they’re installed.Programs like Truecaller, Mr. Number, or various Clear Masters can take control of SMS and block them according to their often flawed databases. Try temporarily disabling or uninstalling such apps for verification.

• 🛡️ Check the Blacklist in the security settings for important numbers.
• 📂 Clean the Spam folder regularly so that the system does not overflow with logs.
• 📉 Turn off Smart Response or other AI features if they interfere with display.

⚠️ Note: Some banking applications require reading permission SMS To automatically enter codes, make sure that the bank application has the appropriate permission in the Settings menu. → Annexes → [Your bank] → Permits.

Problems after system update or firmware

After an operating system update (e.g., switching from MIUI 13 to 14 or HyperOS) configuration file conflicts often occur, the system has updated the kernel and communication modules, but the old network settings have remained the same, causing desynchronization, in which cases messages may come with a huge delay or not come at all.

The first step after the update is to reset your network settings. This will not delete your personal data (photos, contacts), but will return your Wi-Fi, Bluetooth and mobile settings to factory values. Go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. Confirm the action and restart the phone.

If the problem is massive and is reported on forums immediately after the update, it may be a firmware bug, in which case waiting for a patch from developers or, for experienced users, a rollback to the previous stable version through Recovery mode helps.

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Before a major system update, always back up important data and settings via Mi Cloud or locally to be able to roll back in case of critical communication errors.

Sometimes cleaning up the phone and messaging system application (not contacts, but app settings) helps. Go to app management, find Messages, click Clear → All data, and it will return the app to store-like.

Table: Basic error codes and their significance

When diagnosing delivery problems, carriers can send delivery reports or display statuses in logs, and understanding these codes helps determine when a message is lost.

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If the error code indicates overflow of memory or inaccessibility of the center, the problem is solved on the user side in 5 minutes. Errors with 90+ codes often require operator intervention.

When to contact the operator or service

There are a number of situations where self-manipulation is useless and even harmful. If you've tried all the methods: resetting, checking. SMSC, shift SIM-cards to another (from the same or another operator), and messages still do not come - the problem may be on the side of the equipment or base stations.

It is necessary to contact the communication operator if:

• 📞 SIM-The card is very old (issued more than one). 5-7 years ago and does not support modern encryption standards.
• 🚫 The room has a service "Antispam" or "Parental Control", blocking short numbers.
• 📡 There are massive network failures in your area (check on operator’s website or Downdetector).

Xiaomi service center should go if the phone does not see the SIM card at all (writes "Put SIM"), warms up in the antenna area or if the problem appeared after a physical impact / moisture. Repair of the modem part of the phone is a complex procedure that requires professional equipment.