Where to see the serial number on Xiaomi Redmi 3S: all the ways from the box to the service menu

The Xiaomi Redmi 3S serial number is a unique device identifier that can be needed in the most unexpected situations, from checking the originality of the smartphone to warranty repair or unlocking the bootloader. Many users only start looking for this number when it is urgently needed, and finding it is not so easy, especially if the phone does not turn on or the box is long lost.

In this article, we will discuss all possible ways to obtain a Redmi serial number. 3S — From standard (through the settings menu) to little-known (for example, using engineering code or disassembling the device). S/N You'll learn what works even on a phone that's turned off, and where a serial can disappear after being reset to factory settings.

For convenience, we've compiled a comparison table of methods, showing how reliable they are and how they're used, and if you've tried to find a number, but you haven't, there's a section at the end of this article that addresses the problem, including cases where the serial number is displayed as "unknown" or has zeros.

Before you go to the instructions, check if your case is in one of these scenarios:

• 🔄 The phone does not turn on or hovers on the logo - you will find ways №3, №5 and №6.
• 📦 Box and documents are lost, and the number is not displayed in the settings - try the methods №2 and №4.
• 🔧 You have flashed your device or changed your motherboard – the serial number may have changed (for more on this, see Why). S/N may not match»).

1. Serial number in phone settings (the easiest way)

If your Xiaomi Redmi 3S is on and running consistently, it makes sense to start searching for a serial number with the settings menu, which requires no additional tools and takes less than a minute.

Open the Settings app (the gear icon on the desktop) and go to the section:

Settings → About the phone → General information

Here in the feature list you will see the string "Serial Number" (or Serial Number if the interface language is English).The number usually consists of 14-16 characters** (digits and Latin letters) and begins with a combination indicating the model (for example, for Redmi 3S it is often 2016 or 5A).

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Note: If this section displays zeros instead of the number (000000000000000) or the word unknown, it may mean that: 📱 Device unoriginal (fake Xiaomi). 🔧 The motherboard was replaced without the original firmware S/N. 🖥️ Phone stitched custom firmware with errors in system files.

In such cases, try alternative methods from the following sections, but if the number is displayed correctly, we recommend taking a picture or writing it down - this will save you problems in the future.

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The serial number in the settings may differ from what is indicated on the box if the phone was repaired with a change of board, in which case the number on the box (if it is original) takes priority for guarantee.

2.Serial number on the box and documents

The original Xiaomi Redmi 3S packaging always contains the serial number of the device, which is indicated on a barcode sticker located on the end of the box (usually on the side of the side where the Mi logo is depicted), and the number is duplicated on the warranty card (if it is saved).

Serial number format on the box:

• 📌 It starts with letters. S/N or SN.
• 🔢 It's made of 14–16 alphabetic-numeric symbols (example: S/N: 5A2016041234567).
• 🏷️ The label may contain additional data: IMEI, Model (2016037) for Redmi 3S) firmware.

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Note: If the number on the box doesn’t match what’s displayed in the phone’s settings, it could mean: 🔄 The device was in repair with a replacement board (serial number tied to the motherboard). 📦 The box is unoriginal (for example, from another phone). 🛠️ The phone is recovered after loss (for example, bought from hand without a box, and the sticker is forged).In such cases, warranty service at the Xiaomi service center will require a confirmation of purchase (check or data of the Mi Account account to which the phone is tied).

If the box is lost, but you have a warranty card or check, check them – sometimes the serial number is duplicated there, and the number can be specified in the contract of sale (if you bought the phone from hand).

Serial number under the battery (for switched off phones)

If the Xiaomi Redmi 3S doesn’t turn on or is getting stuck on the screensaver, but you have access to its “entrails”, the serial number can be found under the battery. This method requires disassembling the device, so it is only suitable for those who are willing to risk the warranty (if it is still valid) or have experience with electronics.

Step-by-step:

1. Turn off your phone (if it responds to the power button).
2. Remove the back cover - it is attached to the latches, so put it with a plastic card or a mediator on the side of the headphone jack.
3. Gently disconnect the battery plume (if you are afraid of damaging, just bend the battery to the side).
4. Under the battery, you will see a data sticker where the S/N string is the serial number.

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Note: When disassembling Redmi 3S keep in mind: 🔋 The battery is glued, but it can be gently tampered with a plastic blade (do not use metal objects!). 🛠️ The sticker under the battery can be damaged if the phone has been repaired - in this case, the number may not be readable. 📱 If the phone is warranty, disassembly will cancel it (on the box will appear autopsy trace).

If the sticker is erased or missing, try other methods (for example, through the Fastboot or engineering menu). SIM-Cards – Check the inside of the card.

Plastic card or mediator|Screwdriver (cross, if you need to remove the screen)|Lupa (if the number is not visible)|Antistatic bracelet (optional, for safety)|-->

Serial number via engineering menu (#4636##)

Xiaomi’s hidden engineering menu allows you to access technical information, including the serial number, which works even if the phone is not connected to the Internet, but requires the device to turn on and respond to presses.

Instructions:

1. Open the phone (calling) application.
2. Enter the combination: ##4636## (no spaces).
3. In the menu that opens, select the Phone Information (or Phone Information) tab.
4. Scroll down to the Serial Number (may be called Serial Number or SN).

If you see an unknown or an empty field instead of a number, it can mean:

• 📵 Phone doesn't recognize. SIM-map (try inserting an active card and repeating the code entry).
• 🔧 The firmware is modified (for example, custom recaveri is installed).
• 🛠️ The device is not the original Xiaomi (fake).

Alternative engineering code for Redmi 3S:

##225##

It displays information about the screen calibration, but sometimes duplicates the serial number.

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The engineering menu is the fastest way to get a serial number without disassembling the phone, but it only works on the original MIUI firmware.

5. Serial number via Fastboot (for non-working phones)

If the Xiaomi Redmi 3S is not enabled but is responsive to a computer connection (e.g., defined as Qualcomm HS-USB QDLoader 9008), the serial number can be obtained via Fastboot mode.This method requires a PC with ADB/Fastboot drivers installed and minimal command-line knowledge.

Step-by-step:

1. Turn off the phone (if it freezes, press the power button for 10-15 seconds).
2. Press Volume Down + Power and hold until the Fastboot logo appears.
3. Connect your phone to your PC through USB-cable.
4. Open the command line (Win + R → enter cmd) and execute the command: fastboot getvar serialno
5. In the answer, you will see the serialno line: [your serial number].

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Attention: When working with Fastboot: 🖥️ Make sure that the PC has Mi Flash Tool drivers installed (you can download from the official Xiaomi website). 🔌 Use the original. USB-cable – cheap cables can’t transmit data in Fastboot mode. 📵 If the command returns the waiting for device error, try reconnecting the cable or changing it. USB-port.

If the serial number does not appear, try an alternative command:

fastboot oem get_serialno

It runs on some versions of the Redmi 3S with a Qualcomm Snapdragon 430 processor.

6. Serial number through Mi Account (if the phone is tied)

If your Xiaomi Redmi 3S is linked to your Mi Account, the serial number can be found in your personal account on Xiaomi’s website, which is convenient if the phone is lost or not turned on, but you remember the login details.

Instructions:

1. Go to the Mi Account website and log in.
2. In the Devices (or Devices) section, find your Redmi 3S in the list.
3. Click on the device and a page will open with detailed information, including serial number and IMEI.

If the phone doesn’t appear in the list of devices, check:

• 📱 Whether the account was synced to the breakdown (if the phone is new or after a reset, it may not automatically be linked to the account).
• 🔄 The device may be linked to another account (e.g., if you bought from hand).
• 🛠️ If the phone was repaired with a change of board, it can “disappear” from the list of devices in the account.

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Note: The serial number in Mi Account is not updated instantly. If you recently dropped your phone or changed your firmware, the data can be displayed with a delay of up to 24 hours.

If you don’t have access to your account but your phone is turning on, try to restore your password through your email or phone number, and in extreme cases, you can contact Xiaomi’s support team with proof of purchase (check or warranty card).

Why the serial number may not match or be missing

Sometimes users find that the serial number on the box does not match the one displayed in the phone settings, or is not at all, so let's figure out in which cases this is normal and when to be alert.

Reasons for the absence or non-match of S/N:

Especially often problems with the serial number arise after:

• 🔧 Replacement of motherboard – a new number is not always stitched.
• 📱 Custom recaveri installations (e.g, TWRP) — It can damage the data section.
• 🖥️ Incorrect updates via Mi Flash Tool (for example, firmware for another model).

If you suspect that the serial number was changed by fraudsters (for example, when buying a used phone), check it through the service IMEI.info. Enter IMEI (you can find it through *#06#) and compare the data with those listed on the box.

Frequent questions about the Xiaomi Redmi 3S serial number