How to open Xiaomi Mi 9T: unlock the bootloader, reset password and hidden features

Xiaomi Mi 9T

Redmi K20

Snapdragon 730

all-ways-unlock

Many users are having trouble unlocking the Mi 9T because of Xiaomi’s policies, such as limiting bootloader unlocks to a Mi Account, and increasing the requirement to wait for confirmation from 2021, and we’ll show you how to get around these restrictions legally and without the risk of bricking the device.

Important: Unlocking methods are divided into software (via settings or PC) and hardware (using test points or soldering irons), the latter require experience and better trust their service centers. In this article, we will focus on safe ways that you can apply yourself.

1. Unlock the bootloader (Bootloader) on Xiaomi Mi 9T

The bootloader on all Xiaomi smartphones is locked by default, a security measure to prevent unofficial software from being installed. To unlock it on the Mi 9T, you need to go through the official procedure through the Mi Unlock Tool.

Since 2023, Xiaomi has tightened the rules: 168 hours (7 days) must pass between linking an account to a device and unlocking it. This is done to combat phone theft. If you bought a used device, the previous owner must untie your account through Settings → Mi Account → Delete the device.

  • 📱 Step 1: Activate Developer Mode. Go to Settings → About the phone and 7 times click on the version MIUI. You will receive a notification saying, “You are a developer".
  • 🔗 Step 2: Link Mi Account to your phone. Go to Settings → Additionally. → For developers → Mi Unlock status and link your account.
  • ⏳ Step 3: Wait 7 days. During this time, you can not reset or untie your account.
  • 💻 Step 4: Download the Mi Unlock Tool (Windows version) and follow the instructions.

⚠️ Note: If you see a "Couldn't unlock" error (10008) when you unlock, it means that 168 hours have not passed since the account was linked:

  • It's on on the phone. USB-debugging (Settings) → For developers).
  • Used by the original USB-cable (not all cables support data transmission).
  • Xiaomi drivers are installed on the PC (you can download here).

Developer mode activated |Tielded Mi Account to device |Installed Mi Unlock Tool on PC |Phone charged at least 60% |Disabled antivirus on your computer-->

Critical detail: once the bootloader is unlocked, the encryption key will be deleted from the phone, and all data on the internal memory will be erased. Back up through Settings → System → Backup!

2. Resetting of the pattern lock or password

Forgot the password from Xiaomi Mi 9T? there are several ways to regain access, but their effectiveness depends on whether Mi Account and Find Device features were enabled.

If your phone is linked to a Xiaomi account, the easiest way to do this is to reset your password through the site:

  1. Go to account.xiaomi.com and log in.
  2. Choose Find Device → Xiaomi Mi 9T.
  3. Click Unlock Device and confirm the action via SMS or email.

If you do not have a Mi Account attached or you do not remember the data from it, you will have to use the Recovery Mode:

  1. Turn off the phone.
  2. Press Volume Up + Power for 10 seconds until the Mi logo appears.
  3. Select Wipe Data → Wipe All Data (control – volume buttons, confirmation – power button).

⚠️ Note: This method completely erases data from internal memory, including photos, contacts and messages. If the phone was enabled sync with Google Account, contacts and some applications will be restored automatically after logging in.

Official Mi Unlock Tool Officially|Reset via Mi Account|Hard Reset in Recovery|I went to the service center.|Another way.-->

3. Unlock through the Engineering Menu (for Advanced)

If standard methods do not work (for example, if the error "This device is locked" is not valid). 7 You can try to bypass the restrictions through the Engineering Mode, which is suitable for Mi models. 9T base MIUI 12-14.

Instructions:

  1. Open the Phone app and enter the code: ##4636##.
  2. Go to Testing → Single Test → Manual Test.
  3. Enter the command: sys unlock oem (without quotes).
  4. Reboot your phone and try to unlock again via the Mi Unlock Tool.

⚠️ Note: Not all versions MIUI Some firmware may have blocked the engineering menu, and if nothing happens after you enter the code, your version of the software doesn't support the functionality.

What to do if the engineering menu is not opened?
On some firmware Xiaomi blocks access to the engineering menu through USSD-The alternative is to use codes. ADB-Commands: Connect the phone to the PC with the switched on USB-Open the command line and type in: adb shell setprop sys.oem_unlock_allowed 1 Reboot the device. This method doesn't work on all versions. MIUI And they may claim root rights.

Unlocking without waiting 7 days (alternative methods)

The official 168-hour unlocking method is not for everyone, and there are informal methods that circumvent this limitation, but they involve risks:

  • 🔧 Method 1: Firmware through EDL. Requires a special cable and the Mi Flash Tool, suitable for "brick" devices, but can lead to loss of the device. IMEI.
  • 📱 Method 2: Use of vulnerabilities in older versions MIUI. For example, on MIUI 11 You could unlock the bootloader via fastboot oem unlock-go, but this bug was fixed in the new versions.
  • 💰 Method 3: Contact the service center. Some workshops offer 1 to 2 days unlock through official channels (cost) ~1500–3000 ₽).

⚠️ Attention: Methods using EDL (Emergency Download Mode) requires authorization from Xiaomi. Without official permission, you risk getting an account lock or a brick.

Unlocking methodImplementation timeRisks.Cost
Official Mi Unlock Tool Officially7+ daysNo (if you follow the instructions)Free of charge.
Reset via Mi Account5-10 minutesData loss in Hard ResetFree of charge.
Firmware through EDL1-2 hoursLoss of IMEI, account blockingFree (if you have equipment)
Service centre1-3 daysMinimum (depending on the master)1500–3000 ₽

5. Unlocking SIM-map (PIN/PUK)

If Xiaomi Mi 9T request PIN or PUK-insertion SIM-This is not a phone problem, this is a carrier lock:

  • 📞 PIN-Code: This is usually the 4 digits you set when activated. SIM. If you forget, contact the salon with a passport.
  • 🔢 PUK-Code: Indicated on the plastic holder SIM-If you lose your card, call the operator's hotline: 0890 Beeline: 0611 MegaFon: 0500 Tele2: 611

⚠️ Note: If you enter the wrong 10 times in a row PUK, SIM-The card will be permanently blocked and you will have to buy a new one.

1. Reset the device.

2. insert the SIM into another slot (if any).

3. Update the software through Settings → Update the system.

If it doesn’t work, the problem may be a damaged slot or antenna (repair needed).-->

6. Frequent errors and their solutions

When unlocking the Xiaomi Mi 9T, users often encounter typical errors.

  • 🚫 Mi Unlock Tool error 10008: 168 hours after account was linked Solution: wait or try alternative methods (see section 4).
  • 🔌 Phone is not determined by PC: Check the cable (you need the original), install Xiaomi drivers and disable antivirus.
  • 🔒 bootloader locked after firmware: If you installed custom software without unlocking, the phone may stop turning on.Solution: flash official firmware through Mi Flash Tool in mode EDL.
  • 📵 No network after unlocking: It may have crashed IMEI. You can restore it through the engineering menu (code # #4636## → Information → Restore IMEI).

If none of the methods worked, it is possible that your Mi 9T has a hardware lock (for example, after repairing the motherboard), in which case only contacting the service center with a check for the purchase will help.

1. Battery charge (minimum 60%).

2. availability of a backup copy of the data.

3. compatibility of the MIUI version with the selected method.

4. Originality of cable and drivers on PC.-->

Can I unlock the Mi 9T without losing data?
No. When you unlock the bootloader through the Mi Unlock Tool, all the data in the internal memory is erased. The only way to save the information is to back up through Settings → System → Backup before the procedure begins.
What if the previous owner didn’t untie his Mi Account?
Ask them to delete the device from your account via Settings → Mi Account → Delete the device. If you can’t contact them, all you have to do is contact the Xiaomi service center with proof of purchase (check, contract). Use informal unlock methods (see section 4), but this is risky.
How to check if the bootloader is unlocked on the Mi 9T?
Turn off your phone and press Volume Down + Power to log into Fastboot Mode. If you have "Unlocked" on the bottom of the screen, the bootloader is unlocked. If Locked is locked.
Can I unlock the Mi 9T through ADB?
Partially. With ADB, you can only prepare the device for unlocking (for example, turn on OEM Unlock in the developer settings).
Why is the mobile network not working after unlocking?
This is a typical problem when unlocking through informal methods (e.g. EDL), the reason is the loss of IMEI. It can be restored: through the engineering menu (code # #4636##). Using the SN Write Tool (requires authorization from Xiaomi).