Modern Xiaomi smartphones offer users many features to filter incoming calls, but sometimes this protection works against the owner, blocking important conversations.A situation when the subscriber can not reach, and the screen displays a strange icon or a message about blocking, requires immediate intervention in the settings of the system. Often the problem lies in the activated functions of “Antispam” or “Blocking unknown”, which by default can be too aggressive.
There are several levels of protection that can prevent calls from coming: from software filters. MIUI hardware-lock SIM-map PIN-To unlock calls on Xiaomi, you need to consistently check each of these levels, from the phone’s system apps to the mobile operator’s settings. In some cases, you need to reset network settings or even flash the modem if the problem is of a software nature.
In this article, we will take a look at all the possible causes of blocking and provide step-by-step instructions for eliminating them: you will learn how to manage blacklists, configure contact exceptions, and use an engineering menu to diagnose a radio module. It is critical to determine exactly the type of lock before you start, since resetting network settings will delete stored Wi-Fi passwords.
Diagnostics of the type of lock on the device
The first step in solving the problem is to pinpoint the source of the lock. Users often confuse locking a specific number, Do Not Disturb mode and hardware locking. SIM-If the call just doesn't go through, but the beeps are going, it's probably the operator's side or the forwarding settings, and if the call is dropped instantly, or the caller hears the beep, and you don't have anything going on, it's the software filters. MIUI.
Note the icons in the status bar. A crossed-out tube usually indicates activation of Do Not Disturb or On the Plane. In some firmware versions, the lock icon next to the contact means that the number is blacklisted. For diagnostics, you can call your number from another phone and see how the lock screen reacts.
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Use the voice recorder during an incoming call from another number to record the exact message of the operator’s answering machine – this will help you understand exactly where the call is lost.
System logs can also tell you why. Security often stores a history of blocked actions. If you see incoming calls, the built-in antivirus or spam protection module works correctly, but requires exceptions to be configured. The absence of records may indicate a deeper problem with the network module.
- 📱 Check the icons in the status bar for lock symbols or flight mode.
- 📞 Call from another number to track smartphone behavior when incoming call.
- 🛡️ Open the lock log in the Security app to analyze the history.
- ⚙️ Make sure that the Do Not Disturb mode is not activated in the Quick Settings Panel.
Managing built-in Antispam and Blacklist
The most common reason to unlock calls on Xiaomi is the aggressive operation of the built-in Antispam module, which automatically detects spam numbers and blocks them, but sometimes mistakenly blacklists the numbers of couriers, colleagues or government agencies, accessing these settings through the standard Security app, which is pre-installed on all devices of the brand.
Inside the Antispam section, you need to go to the blacklist settings, and here you will see a list of all the blocked numbers, and if you don't have the right contact, you may have activated the lock mode "All Unknown Numbers" or "Hidden Numbers," and disabling these options will make it possible to take calls from any ID, even if they're not stored in the phone book.
☑️ Checking the Antispam settings
Special attention should be paid to blocking settings by keywords or prefixes. If you previously set up SMS filtering, it could affect voice calls. Resetting antivirus settings to factory settings often helps if manually managing lists does not work. After resetting, all previously blocked numbers will be unlocked, so act carefully.
⚠️ Note: When clearing the blacklist, all previously blocked spammers will again be able to contact you. It is recommended not to delete the list completely, but to use the function "Unblock selected spammers».
Setting up the “Do Not Disturb” mode and restrictions
The “Do Not Disturb” mode» (DND) — It's a powerful tool that completely ignores incoming calls unless they're marked as favorites, unlike a blacklist that resets a challenge, DND You can simply not wake the screen and not make sounds, creating the illusion of a broken phone. → Sound and vibration → Don't disturb.
Within the mode settings, there are subtle exception options: You can allow calls from contacts on the Favorite list or re-calls from a single number within minutes. It's a useful feature, but it requires the correct initial configuration. If the mode is on schedule (for example, at night), make sure the time slots are set correctly.
Hidden DND settings
It’s also worth checking for specific application restrictions. If you’re using a third-party caller (like Google or Truecaller), the system may have restricted its background activity. Go to Settings → Apps → All apps, find your phone app and make sure that calls and background permissions are active. Android permission-level locking often looks like a software glitch.
- 🌙 Turn off Do Not Disturb mode in the control panel or sound settings.
- ⭐ Add important contacts to your favorites list to bypass restrictions DND.
- 📱 Check the permissions for the Phone app in the App Management menu.
- ⏰ Make sure that automatic activation of the schedule mode is not activated.
Unlocking SIM-maps PUK-code
If, when you turn on the phone or attempt to make a call, the device requests PUK-code, which means that PIN-code SIM-The card was entered incorrectly three times, and in this state, it is impossible to unlock calls on Xiaomi using conventional methods - the phone completely blocks the communication module until the correct code is entered. PUK (Personal Unblocking Key) is provided by the operator and is usually located on the plastic card where it was located. SIM-ka.
Introduction of the wrong PUK-10 times the code leads to irreversible blocking SIM-In this case, recovery is impossible, and you will need to replace the SIM card in the operator's cabin. Be extremely careful when entering the numbers. If the card is lost, you can try to find the code in the subscriber's personal account on the operator's website or request from the support service.
| Type of code | Number of attempts | Consequence of error | Where to find out. |
|---|---|---|---|
| PIN | 3 | Block, request PUK | User memory |
| PUK | 10 | Full SIM lockdown | Envelope from SIM / Personal Cabinet |
| PUK2 | 10 | Blocking SIM functions | Envelope from SIM / Operator |
| Network unlock code | Depends on the model. | Operator lockdown | Service center / Seller |
After successful entry PUK-The system will propose to install a new PIN-It is recommended to choose a combination that is easy to remember, or disable the request. PIN When turning on the phone in security settings SIM-This will make it easier to use the device, but it will reduce protection in case of phone theft.
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PUK-Code is the only way to restore access. SIM-post-lock PIN-Don't try to guess it unless you're sure of the numbers.
Reset network settings and work with engineering menu
When software methods fail, you may need to reset your network settings, which returns your mobile network, Wi-Fi, and Bluetooth to factory values. It is important to understand that this will not delete your personal files or contacts, but will forget all saved passwords from Wi-Fi networks and Bluetooth headset settings. → Connection and sharing → Reset Wi-Fi, mobile networks and Bluetooth.
For advanced users, you can log in to the engineering menu using the code ##4636##. In the Phone Information section, you can try to switch your preferred network type (for example, from LTE Only to GSM/UMTS/LTE auto). Sometimes the phone sticks in a mode that is not supported by the current operator tower, which leads to the inability to register in the network and receive calls.
The engineering menu can also check the status of the IMEI. If the fields IMEI empty or zeros are displayed, this indicates damage NV-This is a memory partition, which often happens after a failed firmware experiment, in which case software unlocking calls is impossible, you need to restore a backup copy. NVRAM through specialized software.
⚠️ Warning: Changing the settings in the engineering menu without understanding their purpose can lead to complete loss of communication.
Solving the locking problems from the operator
Sometimes the reason for blocking is not the phone, but the carrier side, it can be the service "Number Antidetector" at the caller, you activated the service "Blacklist" on the tariff or bill debt. Operators can also block calls if abnormal activity, such as sending SMS, which often happens when the phone is infected with a virus.
To check the status of services, you need to contact your personal account or call support, the operator can remove all the locks you have installed on their side, and it is also worth checking whether a redirect to another number that may be configured incorrectly is activated. Redirection can be managed through USSD-commands, for example ##002# to disable all types of forwarding.
If the phone is bought from hand and locked under a specific foreign operator (SimLock), unlocking calls will require entering a special code to unlock the network. SIM-The code can be purchased from specialized services, providing IMEI The device, but it is a paid procedure.