Problems with sending text messages to Xiaomi Redmi 9 often come suddenly, leaving the user confused. The phone seems to catch the network, the indicators show a confident reception, but the messages freeze in the status of “Submit” or instantly return with an error. In most cases, the root of the evil lies in the incorrectly prescribed SMSC number, which is responsible for routing your correspondence through the network of the operator.
Changing this setting doesn't require deep programming knowledge or root rights, but the MIUI shell has its own nuances that make it different from pure Android, and we'll look at all the ways we can go from standard settings to using an engineering menu that's hidden from the eyes of the average user.
It is important to understand that the wrong setup can temporarily block the possibility of sending messages, so you need to act carefully. For Russia and CIS countries, the standard message center number usually begins with the +7 code or the corresponding country code, followed by a short numerical code of the operator. Below we will discuss in detail the algorithm of actions for successful replacement of the parameter.
What is SMSC and why is it important for Redmi 9?
SMSC stands for Short Message Service Center, which is a carrier server that receives your text messages and forwards them to the recipient. If your phone doesn't know the address of that server or knows it incorrectly, SMS communication with the outside world becomes impossible. Unlike messengers that work over the Internet, SMS relies solely on this infrastructure.
On Xiaomi Redmi 9 smartphones, the message center number is usually written automatically when you first install it. SIM-The operator transmits this data through a special service protocol, but sometimes this process is interrupted, the configuration file is corrupted or the user accidentally makes changes in an attempt to optimize the communication. As a result, the phone tries to send a message to a non-existent or someone else's address.
It's worth noting that for every carrier (MTS, Beeline, MegaFon, Tele2, etc.), the address of the center is unique. If you change the operator but leave the old settings, or move to a region with a different code, the problem can manifest here, and checking the relevance of the number is the first step in diagnosing any messaging problems.
⚠️ Note: Introducing the wrong number format SMSC This can cause the phone to stop sending any messages until the error is corrected.
Preparing for changes in network settings
Before you get into the technical settings, you need to make sure that the device is ready to make changes. Chaotic actions without preparation can lead to confusion, especially if you have two on your phone. SIM-On Redmi 9, each SIM card is managed separately, and the settings may vary.
Make sure your number has funds on your balance, as some operators may block service requests when the balance is negative, and check if the messaging feature is enabled in the app settings. Sometimes the problem is solved by simply restarting the messaging service or the smartphone itself.
To perform some techniques, you may need access to telephony.Make sure you know the unlock pin code SIM-If you have a card installed, because when you reset your network, your phone can request it again.
If you plan to use the engineering menu (which will be discussed below), make sure that the screen does not turn on the In-pocket mode or any protective films that may interfere with the exact input of numbers.
The most effective way to change SMSC Xiaomi Redmi 9 is the entrance to the engineering menu through a special USSD-This is a modem-level technique that allows you to edit parameters that are hidden in the normal interface. MIUI Access to this menu may be restricted or require special activation.
To start, open the standard "calling phone" and dial the code ##4636##. If the menu opens, you'll see a list of options. Select "Phone Information." If you have two. SIM-maps, select the one you want to change the settings for. In the menu that opens, find the field SMSC.
In the input field, you will see the current number in HEX format (hexadecimal code) to change it:
- 📱 Copy the current value or take a picture of the screen just in case.
- 🔢 Enter a new number in the format HEX (It must be converted from a regular telephone format).
- 💾 Click the “Update” or “Install” button).
How to convert a room to HEX format
Regular number. +79,160,000 HEX It will look like 07917496000000F0 (last F0 It depends on the type of numbering. For accurate conversion, it is better to use the online calculators “Phone to” HEX», Because a single digit error will cause a failure. HEX-The number format often starts with 07 or 08, and at the end you add control characters. Be very careful when you type manually. If the ##4636## code doesn't work and the menu doesn't open, then your firmware version is blocking that access. In this case, move to the next method or use third-party applications to change the region code. Method 2: Standard message settings MIUI In some versions of the shell MIUI Redmi 9 has a direct number change via settings, which is less risky, but also less functional, and is suitable if the input field is available and not blocked by the operator. Open the Messages app, click three dots in the corner of the screen, and select Settings. then go to Additional or Settings. SIM-This can show the field "Message Center Number." If it's active, just type in a new number in an international format. Often users are faced with a situation where the field is gray and not available for editing. SIM-In this case, the standard methods will not change anything. Operator Region Number Type Editing status MTS Moscow Federal Often blocked Beeline St. Petersburg Regional Available MegaFon Kazan Federal Partial Access Tele2 Yekaterinburg Regional Available Please note that even if the field is available, the system may not save the changes immediately.After entering the number, be sure to click "Save" and restart the device. Only after turning on, check if the settings have been applied. 📊 Which operator are you having problems with SMS?MTSBILINEMegaFonTele2If the standard methods on Xiaomi Redmi 9 don’t work, you can try changing the region of the phone. The logic is simple: messaging center settings are often tied to the region selected at the first start-up or in the system settings. Changing the region can shake up network settings, requiring you to download the Country Code Setter app from Google Play, then launch the program and select the country that matches your carrier, and make changes to your configuration system files. Once you change region, the phone may request a reboot. You can agree to do this. Once you turn on, check your SMS settings again. Sometimes this method will unlock the manual number field or automatically pull up the correct values from the operator, but this method has its own risks, changing the region can affect the operation of other system applications, the frequency of updates and even the display of language in some menus. Use it only if other methods are powerless. ⚠️ Note: When you change region through third-party apps, date and time settings may reset. Check them immediately after the reboot to avoid problems with security certificates in the browser. Alternative solutions and reset network settings When manually change SMSC If you can't or can't get it done, you need to take more radical, but safer measures, and if you reset your network settings, you can get all the connectivity settings (Wi-Fi, Bluetooth, mobile) back to factory values, and that often helps if you have a lot of junk in your configuration files». To perform a reset on Redmi 9, go to Settings → The phone. → Resetting settings → Reset your Wi-Fi, mobile network and Bluetooth settings. Note that Wi-Fi passwords will have to be re-entered, but no personal files (photos, contacts) will be affected. SIM-If your SIM card has been in use for more than 5 years, its chip may have worn out or become obsolete, leading to errors in reading service data. Replacing the SIM card in the operator's cabin often solves the problem out of nowhere. 🔄 Completely reset your network settings via your phone menu. 📲 Extract. SIM-map, wipe the contacts with a lasticle and paste back. 🏪 Visit the communication room for replacement SIM-new-card (USIM). If nothing helps, perhaps the problem lies not in the phone, but in the services of the operator. Make sure that the number is not blocked outgoing SMS or not exhausted the limit of free messages (if the tariff is old). 💡Before resetting your network settings, make sure to write down passwords from important Wi-Fi networks if they are not synced with your Google account. Restoring access to the router can take time. Diagnostic problems with sending SMS After making changes to the Xiaomi Redmi 9 settings, you need to check the result. Do not rely only on sending a test message to yourself, as incoming SMS from yourself can come even when broken. SMSC (The best way to check is to send a message to another operator's number or ask a friend to send you a response, and you can also use short number services to check balance if they support feedback. If a message is sent but not delivered (the "Delivered" status has not appeared), the problem may be on the recipient's side or in roaming. 💡Successful shift SMSC The delivery report is confirmed by the delivery report to the number of another operator (DLR) It's a message chain problem, and in some cases, it helps to turn on and off flight mode, and it causes the modem to re-register with the updated parameters. 2-3 Why don't you open the engineering menu on Redmi? 9? On the new versions MIUI code-access ##4636## This is not a phone error, but a manufacturer limitation, so use the Country Code Setter app or reset the network settings. Can we change? SMSC No root rights? Yes, in most cases, root rights are not required. Standard user rights, an engineering menu or an application are enough to change the region. Root is only for deep editing system files if all other methods are blocked. What if after a change of location? SMSC Immediately return the original message center number. If you don't remember the old value, reset the network settings or extract and paste it. SIM-The card is re-designed, the operator must send the automatic settings. SMSC No, changing the number of the message center only affects the classic messaging. SMS and MMS. Messengers (WhatsApp, Telegram, Viber) use the Internet channel (Wi-Fi or mobile data) and from settings SMSC dependency.