How to find out the real age of Xiaomi smartphone

Buying a Xiaomi smartphone is always a lottery, especially if you are considering options in the secondary market or in stores selling “grey” appliances. The appearance of the device may be perfect, but no one will guarantee that the gadget has not been in stock for three years or used as a test stand in the store.

Unlike the iPhone, where the release date is often hidden in an encrypted serial number, there are more transparent verification methods in the Android ecosystem and specifically the Xiaomi brand. However, they are scattered across different menus or require the use of special commands. In this article, we will analyze all the available methods, from simple settings to engineering codes, so you can accurately determine when your phone came off the conveyor.

Understanding the age of a device is critical not only to estimating its market value, but also to planning upgrades. Older models may no longer receive security patches, making them vulnerable to use. Let's figure out how to get this information without installing suspicious applications from unverified sources.

Checking through the About Phone menu and battery status

The most obvious, but not always informative, way to go is to look at system settings. In modern versions of the MIUI shell and the new HyperOS, developers try to hide unnecessary technical information from the average user so as not to overload the interface. However, in some models, the date of the first activation or the approximate production period may be displayed in the status section.

First, you need to go to the Settings menu. → The phone. Here, you should pay attention to the line "Version." MIUI» Or, "Android Version." Clicking on it a few times can get you to the extended menu, where sometimes (but rarely) additional technical information appears.

Inside this menu, find the battery item, and although it's hard to see the exact release date, the indirect indication of age is the charging cycle. If the phone's a year and the charging cycles are 500, it's been in use or in a warehouse for a long time with the processes on, and it's often the serial number (S/N) that will be the key to the next section.

⚠️ Warning: Don't blindly trust the date of purchase on the check if you buy a used device. The seller could buy a phone, use it for a year, and then sell it to you as "new." Only the date of production in the factory matters.

Sometimes the Status section shows the date of the first activation of the device if the phone was registered in the Mi Account immediately after unpacking, which is the most accurate reference point for used technology, and if the phone has never been connected to the network, this graph will be empty.

Decoding of serial number (S/N)

The serial number is a device passport that contains encrypted information about the date and place of production. Xiaomi S/N format can vary depending on the year of manufacture and manufacturer, but the general logic remains similar. Usually the number consists of 10-12 characters, where the first digits or letters indicate the year and month.

The most common format for modern models is a sequence where the first two characters represent a year and the next two characters represent a month. For example, if the number starts with 2305, it can mean May 2023. However, there are also letter encodings where a certain Latin letter corresponds to the year.

• 📅 Year of issue: often encoded by the first two digits (21, 22, 23) or letter.
• 📅 Month of production: follows the year, indicated by two figures (01-12).
• 🏭 Factory code: The last symbols often point to a specific assembly line.

To find the serial number, use the *#06# combination in the Phone app or look at the sticker on the back cover (if it is retained) and on the box. It is important that the number on the box, in the system and on the case (if it is read) match. A single digit discrepancy may indicate a replacement case or a rephab (restored device).

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The serial number can also be found on your Google account. Go to google.com/android/find, select a device, and the information about it often shows an S/N that matches the system number.

It's worth noting that some global firmware versions may have different S/N formats than their Chinese counterparts, and if you bought a phone that came from China but was flashed onto the global, standard spreadsheet decoding might fail, and in such cases, you'd better rely on IMEI verification.

Use of engineering menus and codes

The engineering menu is a hidden part of the system, designed to test equipment by developers, and on Xiaomi smartphones, access to it is often limited, but basic information is available. USSD-codes in dialer (calling ringer).

Enter the code ##6484## or ##4636##. The first code opens the CIT menu, where you can check all the sensors, screen and sound. The second code takes you to the testing menu, where in the Phone Details section you can sometimes find more in-depth information about the time and status of the network, which indirectly indicates the age of the SIM card and device.

CIT menus often have Version or Hardware Info, and if you click on it, you'll see a detailed breakdown by component. While there may not be a precise day-month-year date, the hardware version (such as the screen controller firmware date) will give you an idea of when the phone was assembled. If the component firmware date is 6-8 months older than the stated sales date, that's fine (warehousekeeping).

Codes to check Xiaomi:




*#06# - Displaying IMEI and serial number


#6484## - Engineering Menu (CIT)
#4636### - Android Test Menu

⚠️ Warning: Be careful in the engineering menu. Do not change the settings in the sections, the value of which you do not know (especially in the paragraphs). RF Test or Band Selection, as this may result in lost communication or incorrect operation of modules.

If standard codes don't work (operator locks them or a specific version of dialer is installed), try entering code ##3646633##. This is an alternative input to the engineering menu for some MediaTek processors that are used in Redmi's budget models. For Snapdragon processors, this code is usually irrelevant.

Official IMEI check on the Mi website

The most reliable method, which gives a guaranteed correct result, is the use of an official authentication service. Xiaomi maintains a database of all released devices, and you can get accurate information from the unique IMEI identifier.

IMEI (International Mobile Equipment Identity) is a 15-digit number unique to each mobile device, which is assigned in the factory and sewn into the communication module, you can find it by dialing *#06# or looking in Settings → About Phone. For dual-symbol smartphones, there will be two IMEI numbers, you can use any one.

The algorithm of actions is as follows:

1. Go to the official checkout site (usually mi.com/global/verify or regional versions for your country).
2. Enter the 15-digit IMEI code in the appropriate field.
3. Get a CAPTCHA check.
4. The system will give you the status of the warranty and, most importantly, the date of activation or the date of termination of the warranty.

Knowing the warranty expiration date (usually 1 year from the date of purchase/activation), you can easily calculate the age of the phone. If the warranty expired in May 2023, then the phone was activated (purchased) in May 2022, this is the most accurate way to determine the age of the used device.

This is the time that the phone has spent in distributor warehouses and stores, so if it's made in January and activated in March, that's perfectly normal.

Using ADB to get an accurate date

For advanced users who want to access hidden system logs, Android Debug Bridge (ADB) is the ideal tool, which allows you to pull out the exact firmware build date and sometimes the date of the first turn on, which is not displayed in the usual interface.

For this you will need a computer, USB-cable and installed drivers ADB. On the phone, you need to activate the developer mode (7 times click on the build number in the About Phone menu) and enable debugging by USB. After connecting to the PC, execute a command to obtain system properties.

adb shell getprop | grep build.date

This command will show the compilation date of the current installed firmware. If the phone has never been reflashed (which is typical for new devices), this date will be very close to the date of exit from the assembly shop, the difference can be from 2 weeks to 1 month.

You can also try asking for information about the time of the system, although after the restarts, this data is reset.

adb shell dumpsys battery

It will show the wear and tear of the battery and the temperature, which, combined with the firmware assembly date, gives the full picture: If the firmware is fresh (assembled a month ago), and the charging cycles are in the hundreds, the phone is clearly used, perhaps with a replacement battery or re-shopped for sale.

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Comparing firmware build date (via ADB) and warranty activation date is the best way to identify “refurbished” devices sold as new.

Table of conformity of codes in serial number

So to keep you from guessing, we've developed a composite table that can help you navigate numerical notations quickly, and note that the encoding can change, and for very old or experimental models, the rules may differ.

The table shows approximate correspondences. The letter year is often after the plant's digital prefix. For example, in CW12345678, the letter W may indicate 2022. However, the first two digits remain the most reliable indicator if they are present explicitly (e.g., 2205..).

And the month, too, is obvious if you have 01 to 12 after a year, but sometimes you have codes where the month is A-L (where A is January, L is December, excluding I), a system that has been used in some batches to save space or protect against counterfeiting.

Frequently Asked Questions (FAQ)