Xiaomi’s “This device is locked”: why it appears and how to remove the bootloader lock

You turned on a Xiaomi, Redmi or POCO smartphone, but instead of the usual boot screen, you saw the words "This device is locked" on a black background? This means that the device activated bootloader lock, a security mechanism that prevents unauthorized changes to the firmware, which can occur after a reset, a failed update or an attempt to install custom firmware.

In this article, we will discuss in detail:

• 🔍 Why a message appears and what it means for device security;
• 📱 Official ways to unlock through Xiaomi tools (linked to your Mi Account);
• ⚙️ Alternative methods for power users (including risks and consequences);
• ⚠️ What to do if the unlock does not work or the device is “bricked».

Important: the bootloader unlock procedure resets all data on the device to factory settings. If there are important files on the phone, it will be impossible to restore them after unlocking without a prior backup.

What does this device mean in Xiaomi?

The message "This device is locked" appears on the Fastboot screen and signals that the phone bootloader is locked, a standard Xiaomi protection introduced to prevent:

• 🛡️ Installation of informal firmware (custom) ROM), which may contain malicious code;
• 🔄 Unauthorized rollback of the version MIUI (Downgrade, which can disrupt the system;
• 📱 Data theft in case of loss of the device (without unlocking the bootloader, the attacker will not be able to reflash the phone).

The lock is activated automatically on all modern Xiaomi, Redmi and POCO devices released after 2016, with the exception of some models for the Chinese market (for example, the first generation Mi Mix series), where the bootloader could be delivered unlocked.

⚠️ Note: If you bought a phone with your hands and encountered this inscription, there is a high risk that the previous owner did not untie the Mi Account from the device, in which case unlocking through official tools will be impossible without his participation.

The following is the phrase “This device is locked”.

The message about the bootloader lock may appear in the following situations:

If the phone is stuck on a screen with this inscription after self-manipulation (firmware, root rights), most likely, the problem software. If the message appeared spontaneously (without user action), this may indicate a hardware defect, such as wear of flash memory.

The official way to unlock the Xiaomi bootloader

Xiaomi provides a legal unlocking tool, the Mi Unlock Tool, which requires a device-based Mi Account and wait (usually 7-15 days) to be linked.

1. Link your Mi Account to your phone: 📱 Go to Settings. → Xiaomi account → Mi Cloud; 🔗 Turn on synchronization and confirm binding through SMS/email; 🔐 Enable the Settings option → Additionally. → Unlocking OEM (Android 8+).
2. Download the Mi Unlock Tool: 🖥️ Official page: en.miui.com/unlock (authorization required); ⚠️ Use only the latest version – older versions may not support newer models.

Run the unlock:

• 🔌 Connect your phone in Fastboot mode (press the Power). + Vol− off-set);

⚠️ Note: If you are trying to unlock a phone with a Mi Account tied to someone else, the system will require the previous owner to enter the password. Without it, unlocking is impossible - you will have to contact the service center with proof of purchase.

Backup your data (all files will be deleted) |

Charge your phone at least 60% |

Make sure that drivers are installed on the PC ADB/Fastboot|

Disable the antivirus (it can block the utility) |

Use the original USB-cable (not cheap analogues)

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Alternative Unlocking Methods (for Power Users)

If the official method is not suitable (for example, due to a linked account), there are informal methods, which are risky and can lead to a complete loss of operation of the device (brick).

1. Unlock through EDL-regimen (Qualcomm)

The method works on devices with Qualcomm processors (most Xiaomi/Redmi).

• 🔧 Paid credit for authorization in Mi Flash Pro (about) $5–10);
• 📂 Firmware file in.mbn format for your model;
• 🖥️ Mi Flash Tool and Qualcomm Drivers HS-USB QDLoader 9008.

Algorithm:

1. Transfer the phone to EDL mode (usually by closing contacts on the board or via adb reboot edl);
2. Connect to the PC and wait for the device to be defined as QHUSB_BULK;
3. In the Mi Flash Tool, select a firmware file and press Flash.

2. Exploits to bypass lock (on older models)

Some devices (e.g. Redmi Note 3/4, Mi 5) have vulnerabilities that allow you to unlock the bootloader without waiting.

• ❌ It only works on older firmware. MIUI 10;
• ❌ Can trigger an anti-Rollback (irreversible lock);
• ❌ Requires exact matching of bootloader version and firmware.

Before using alternative methods, assess the risks:

• 💀 Loss of warranty – Unofficial unlocking voids warranty obligations;
• 🔥 The risk of “brick” – wrong actions can make the phone unrepairable;
• 🛡️ Security vulnerabilities – unlocked bootloader makes it easier to install malware.

What to do if the unlocking does not work?

If after all the manipulations the phone still shows “This device is locked”, check the following points:

If none of these methods worked, there are two options:

1. Contact the Xiaomi service center - you will need a check or a warranty card;
2. Use paid services of specialists - some workshops offer unlocking through EDL Guaranteeed (price from 1,500) ₽).

💡

Before visiting the service center, take a screenshot of a screen that says "This device is locked" and write down the serial number of the phone (under the lid or on the box), which will speed up the diagnosis.

How to avoid blocking the bootloader in the future?

To avoid the problem again, follow the simple rules:

If you’re actively experimenting with firmware, consider buying a model with an unlocked bootloader out of the box. For example, some versions of the POCO F1 or Mi A2 (Android One) came with an open bootloader.

💡

Even after successfully unlocking the bootloader, the Mi Account is still linked to the device, which means that once the settings are reset, the phone will again require you to enter your account data.

FAQ: Frequently Asked Questions About "This Device Is Locked"