How to set up mobile Internet on Xiaomi Redmi 9: from APN to network selection

Xiaomi Redmi 9 remains one of the most popular budget smartphones even in 2026, but many users face problems when setting up mobile Internet. APN-profile is lost after updating MIUI, The phone is not “seeing” the network. 4G, Although the SIM card supports it, in this article we will discuss all the ways of manual and automatic configuration, from basic parameters to hidden functions of the engineering menu.

Feature of Redmi 9 (model M2003J15SC/M2004J19C) in that which he maintains before 18 range LTE, But by default, it might not work on the fastest frequencies of your operator. B7 (2600 MHz, and Tele's2 — B20 (800 MHz. If the smartphone is stuck on 3G, The problem is often the wrong choice of network.

We're not going to be limited to standard tips like "reset your phone," but instead, we're going to show you how:

• 🔍 Find hidden settings of modified firmware MIUI, Which are not in Android stock
• 📡 Forced to switch to 4G, If the smartphone is persistently holding on to 3G
• 🔧 Restore APN, If they are missing after resetting or updating
• 🚨 Diagnose hardware problems (e.g. antenna damage)

1.Preparation: Checking SIM card and network support

Before digging into your smartphone settings, make sure the issue isn't on the carrier or SIM side.Redmi 9 supports:

• 📶 2G: GSM 850/900/1800/1900 MHz
• 📶 3G: WCDMA 850/900/1900/2100 MHz
• 📶 4G LTE: FDD-LTE B1/3/5/7/8/20/28, TDD-LTE B38/40/41 (before 150 Mbit/s)

If your SIM card is older than 2018, it may not support VoLTE or LTE-Advanced. For example, Beeline from 2023 turns off 3G in some regions, and old SIMs automatically stop catching the Internet. The Redmi 9 smartphone does not support 5G, but this does not prevent it from working on 4G+ networks with frequency aggregation (if the operator provides such an opportunity).

⚠️ Attention: If you use a nano-SIM SIM with a micro-SIM adapter, the contacts may not fit well, which leads to periodic network "disappearance.

2. Automatic setting of mobile Internet

The easiest way is to let the operator set the parameters himself.

1. Open the Settings → SIM cards and mobile networks application.
2. Choose your SIM card (if there are two).
3. Slip on Access Point (APN) → Reset to default values.
4. Send. SMS textual: 📩 For MTS: Internet number 1234 📩 For Beeline: Internet at 5100 📩 For MegaFon: 1 in 5049 📩 For Tele2: Internet at 679

In 1-5 minutes, the settings will come in the form of SMS, confirm their installation. If the message does not arrive, check:

• 🔄 Is there a lockdown? SMS from the operator (sometimes switched on by default).
• 📵 Is not activated mode in the plane or Save traffic.
• 📱 Is it worth the checkmark? 2G network-setting.

SIM card is active and not blocked

Airplane mode is off.

The signal level of the network is not lower than 2 divisions

SMS-Operator center is not blocked-->

⚠️ Warning: If the Internet never works after you set it up automatically, don't rush to drop your phone. APN manually (button Remove) APN in the settings) and repeat the procedure.

3. Manual setting of APN for all operators

If the automatic setting doesn't work, you'll have to enter the settings manually.

Settings → SIM cards and mobile networks → [Select SIM] → Access Points (APN) → Add APN

Below are the current parameters for each operator (data for 2026):

After entering the parameters:

1. Save the APN (Save button in the upper right corner).
2. Select the profile created in the APN list (should be ticked).
3. Reboot your smartphone.

💡

If the APN is missing from the list after saving, check if the profile name has Cyrillic or special characters. MIUI sometimes resets such profiles. Use only Latin and numbers.

4. Forced 4G network selection (if the phone is "stuck" on 3G)

Redmi 9 automatically selects the network by default, but sometimes this algorithm fails. For example, if your region has a weak 4G signal, the phone can stick to 3G and not switch back.

1. Go to Settings → SIM cards and mobile networks → [Select SIM] → Network type.
2. Instead, automatically select LTE Only (or 4G/3G/2G if the first option is not available).
3. If LTE Only is not available, use the engineering menu:

1. Dial in the phone app: ##4636##


2. Select "Phone Information"




3. Scroll down to "Installation of Network Type"




4. Select "LTE only"

If the Internet is gone after that, then your region is not getting 4G or your SIM card is not supporting this standard.

5 Diagnostics of Problems: Why the Internet Is Not Working

If after all the manipulations of the mobile Internet and did not work, check the following points:

• 📶 Signal level: If in the status line of division 1-2, try moving closer to the window or going outside.Redmi 9 does not catch the net well in basements and elevators.
• 🔄 Roaming: In SIM card settings, turn off National Roaming and International Roaming if you are not abroad.
• 🔒 Blocking: Check the balance and status of the mobile Internet service in the operator's personal account.
• 🛠️ Hardware problems: If the smartphone fell or got wet, the communication module could have been damaged).

For deep diagnosis, use service codes:

• IMEI check: *#06# (must match the sticker under the battery)
• Antenna Test: ##4636## → Phone Information → Signal.
• Check the lock operator: ##7594## (if the phone was tied to a specific operator).

💡

If Disconnected or Out of Service is displayed in the network status (#4636##), the problem is most likely on the carrier or SIM card side, not the phone.

6. Additional settings to speed up the Internet

Even if the Internet works, it may be slower than expected, and here are a few ways to optimize it:

• 🚀 Turn off traffic savings: In Settings → Battery and productivity → Save traffic uncheck the box from mobile data.
• 📊 Reset the network's statistics: Sometimes MIUI Limit speed once you reach the limit. Reset the counters to Settings. → SIM cards. → Use of data → Reset the statistics.
• 🔗 Use it. IPv6: In the settings APN add to the Type field APN default,supl,ia if the operator supports).
• 🔄 Update: In older versions MIUI (Below 12.5) there were bugs with the communication module. → The phone. → Updating the system.

If you use two SIM cards, make sure that the data priority is correctly set:

Settings → SIM cards and mobile networks → Priority of mobile data

7. Addressing specific problems

Some errors are only found on Redmi 9 due to the features of MIUI firmware.

🔴 Problem: The Internet works, but the icon 4G not displayed

This is a MIUI bug where the indicator shows H+ or 3G, although LTE is actually used.

1. Install the NetMonster app from the Play Market.
2. Open it and see the real network type in the Network Info section.
3. If there is LTE, but the icon does not change, reset the network settings: Settings → System → Settings Reset → Reset settings Wi-Fi, mobile network and Bluetooth

🔴 Problem: Mobile Internet disappeared after the update

MIUI updates sometimes reset APN settings. Try:

1. Delete all saved APNs (Remove APN button in settings).
2. Manually add the operator profile (see section 3).
3. If it doesn’t work, roll back to the previous version of MIUI via Fastboot (instructions on Xiaomi’s official website).

🔴 Problem: Phones don't catch the network in some places

Maybe the search engine's turned off.

Settings → SIM cards and mobile networks → [Select SIM] → Network Search → Automatically

If that doesn’t work, check to see if 2G Only is on in the engineering menu (#4636###).

FAQ: Frequent questions about mobile internet