The situation when a message gets stuck in the “Sending” status or is returned with an error is familiar to many Android users. This can happen at the most inopportune moment: during an important confirmation of a transaction, when trying to contact loved ones, or during work correspondence. The problem is widespread and affects devices from different manufacturers, from budget models to flagships.
The reasons for the failure can be trivial, for example, lack of account balance, or deep, associated with damage to system files. messenger. Often users begin to panic and blame the device itself for the breakdown, although in 80% of cases the problem lies in incorrect network parameters or configuration failure SMSC. Before taking your phone to the service, you should carry out independent diagnostics.
In this article we will analyze in detail all the possible factors blocking the transmission of short messages. We will look at both software settings and hardware aspects of the work SIM cards. You will learn how to check hidden network settings and reset settings to factory settings without losing personal data.
Basic connection and balance checks
The first thing that needs to be ruled out is problems on the side of the mobile operator. Even if you have an unlimited Internet package, the tariff for voice communications and SMS may be separate. Check your balance via USSD command or operator app. Sometimes the balance goes negative unnoticed due to the subscription fee being charged at the beginning of the month.
Make sure that the network indicator on the screen shows a stable signal. If you are in an area with poor coverage (basement, elevator, remote area), the message will not go away until the phone finds the tower. Try moving to a window or going outside. Temporarily turn it on and off Airplane modeto force re-register the device on the network.
⚠️ Attention: If you are using a dual-SIM smartphone, check which SIM card is selected for sending messages by default. The settings may be lost after a system reboot or update, and the phone tries to send an SMS through a slot with a card that has no funds or no coverage.
You should also make sure that the recipient's number is entered correctly. Some operators require a country code, others do not. Try saving the number in international format (for example, +7 instead of 8) and send a test message again. Errors in contacts often cause silent sending failure.
Incorrect message center settings (SMSC)
One of the most common technical reasons is a failure in the message center settings. Each operator has its own unique number SMSCthrough which all incoming and outgoing texts are routed. If this number in the phone settings is changed, erased or entered with an error, sending becomes impossible.
You can check and change this data through the standard messages application or the engineering menu. The path to the settings may differ depending on the shell: Samsung One UI, Xiaomi MIUI or clean Android. Usually the option is hidden in the settings menu of the SMS application itself, and not in the general settings of the phone.
- 📱 Open the Messages application and tap on the three dots in the corner of the screen.
- ⚙️ Go to section
Settings→Advanced(orService messages). - 📍 Find the item
Message Center(Service Center) and check the number with your operator's data.
If the field is empty or the number differs from the official one, correct it manually. For Russian operators, this data is standard, but may change when roaming. If you have difficulties finding the menu, you can use secret codes, for example, ##4636##to get to the testing menu, which also displays information about the cell and message center.
Message center codes for the main operators of the Russian Federation
MTS: +79160000911, Beeline: +79037000911, MegaFon: +79262000911, Tele2: +79600000911. These numbers are relevant for the home region; in roaming they may differ.
Application conflicts and data cache
Modern smartphones allow you to install third-party messaging clients, such as Textra, QKSMS or specialized apps from manufacturers. software can block the delivery service. The system simply does not understand which application to give priority to sending.
The accumulated cache and application data can become damaged over time. This causes the app to freeze when trying to establish a connection to the network. Clearing the cache is a safe procedure that does not delete your correspondence, but resets temporary configuration files. data-i="67">Settings → Applications → Messages → Storage → Clear cache
Settings → Applications → Messages → Storage → Clear cacheIf simple clearing does not help, try clearing the application data. Warning: This action may delete your chat history if it is not synchronized with the cloud or not saved separately. After this, the phone will prompt you to configure the application again as when you first started it.
☑️ Diagnosis of software failure
Problems with the SIM card and slot
The physical condition of the SIM card plays a critical role. The contacts on the chip may have become oxidized, dirty, or scratched. Also, the card itself could be outdated: old Mini-SIM format SIM cards sometimes do not work correctly in modern Nano-SIM slots, especially if they were cut manually with scissors.
Try to remove the tray, wipe the SIM card contacts with a soft eraser or an alcohol wipe and insert it back. Make sure the card fits snugly and does not wobble. If you have a smartphone with two slots, move the card to another slot. This will help identify the malfunction of a specific reception slot.
| Symptom | Possible cause | Test method |
|---|---|---|
| No network or "Emergency Only" | Slot malfunction or cards | Rearrangement to another slot |
| SMS are sent every other time | Oxidation of contacts | Cleaning contacts with alcohol |
| Phone does not see SIM | Mechanical damage chip | Replacement of SIM with the operator |
| Errors during registration | Incompatibility of form factor | Replacement with a new Nano-SIM |
The most reliable diagnostic method is to insert your SIM card into another phone. If messages are sent there without problems, then the problem is with your smartphone. If the error persists, contact the communication store to replace the SIM card; this service is usually free if you keep the number.
When replacing a SIM card, ask your operator to check the binding of the “Banning SMS sending” service on your number. Sometimes this blocking is placed automatically due to suspicious activity or by mistake.
The impact of system updates and blockers
After updating the operating system Android or installing a security patch, permissions for applications may be lost. The system may have automatically revoked the Messages app's right to access the network or phone. This is a common problem after major OS version updates.
Check access rights manually. Go to the application settings, find your messenger and make sure that the “Phone”, “SMS” and “Contacts” items are allowed. Without these permissions, the app will not be able to initiate sending.
It is also worth paying attention to the installed antiviruses and spam blockers. Aggressive security settings can perceive an outgoing message as suspicious activity and block it at the system level. Try temporarily disabling third-party antivirus or adding the recipient's number to the white list.
⚠️ Attention: Interface and menu settings may vary depending on the Android version and the manufacturer's shell. If you do not find the item in the specified location, use the search in the settings by entering the word "Permissions".
Resetting network settings as a radical solution
If none of the previous methods helped, perhaps a critical conflict of network protocols has accumulated in the system. Resetting your network settings will return your Wi-Fi, Bluetooth, and cellular settings to factory defaults. This will not delete your photos, contacts or applications, but will forget saved Wi-Fi passwords.
This procedure effectively solves problems associated with communication modules not working correctly after multiple configuration changes. It forcibly overwrites the radio module configuration files.
Settings → System → Reset settings → Reset Wi-Fi, mobile data and Bluetooth settingsAfter the reset, the phone will reboot. You will need to re-enter the password for your home Wi-Fi network and check the operation of SMS. In most advanced cases, this action restores the functionality of the messaging service.
Resetting network settings is a safe method of treating software communication errors, since it does not affect the user’s personal data, unlike a full reset to factory settings.
Why are SMS not sent only to certain contacts?
If messages go to some subscribers, but not reach others, the problem is most likely not with your phone. Perhaps the recipient's number is blocked by himself, or his inbox memory is full. It is also worth checking if this contact has been added to your blacklist by mistake.
Can a long message (MMS) not be sent due to SMS settings?
Yes, if you have mobile data turned off, MMS (multimedia messages with photos) will not be sent, even if regular texts are sent. MMS requires active internet (3G/4G/LTE). Check whether the mobile data is turned on in the notification shade.
What to do if a “Not Delivered” error appears immediately after sending?
Such an error usually means that the network received the message, but was unable to transmit it to the recipient. Reasons: the recipient's phone is turned off, he is out of reach, or his number is blocked by the operator for non-payment. Try calling this subscriber to check the connection.
Does power saving mode affect sending SMS?
In extreme power saving modes, the system can limit the background activity of applications, including the message delivery service. If you have Ultra-Saving mode enabled, try disabling it and resending the message.