When buying a used Xiaomi smartphone or even a new device out of the box, many people are faced with the question: how to find out the real year of its production? This information is critical for assessing battery wear, verifying the authenticity of the gadget and even for warranty maintenance. The manufacturer does not always specify the release date on the package, and in the phone settings it does not. However, there are at least 5 reliable ways to determine the age of your Redmi, POCO or Mi – from analyzing the serial number to hidden service codes.
In this article, we’ll look at all the current verification methods, including those that work even without access to the device itself (for example, if you buy a phone online), and focus on the nuances for different regions – Chinese versions (China ROM) and global (Global ROM) may differ in labeling, and you’ll learn why the date on the box and the actual year of production sometimes don’t match, and how this affects the cost of the phone.
1. Serial number check (S/N) — most accurate
The serial number is your Xiaomi’s unique identifier, which contains encrypted information about the date of production.
- 📦 On the sticker under the battery (if the body is removable) or on the tray SIM-map.
- 📱 In the phone settings: Settings → The phone. → General information → Serial number.
- 📄 On the device box (usually on a barcode sticker).
Xiaomi serial number usually has a format XXXXXXXXXA or XXXXXXXXXB, where the last 2 characters are coded for the month and the year:
| The last symbol | Year of production | Penultimate symbol | Month of production |
|---|---|---|---|
| A | 2017 | 1-9 | January-September |
| B | 2018 | A | October. |
| C | 2019 | B | November |
| D | 2020 | C | December |
| E | 2021 | D | January (next year) |
Example: if your serial number ends in B5, then the phone was released in May 2018. For models after 2022, Xiaomi has changed the format - now the year can be coded with the first digit after the prefix (for example, 2203... = March 2022).
⚠️ Warning: Serial numbers are often forged on fake phones.Verify authenticity through Xiaomi's official website at the link.
2.IMEI Analysis: What You Can Learn About a Phone
IMEI (International Mobile Equipment Identity) is a 15-digit code that is assigned to each mobile device, which does not contain direct information about the date of production, but allows you to check:
- 🔍 The authenticity of the phone (is it not a clone).
- 📅 Approximate year of release (via operator databases).
- 🌍 Region of Sale (Chinese or Global).
You can find out about IMEI:
- 📱 In settings: Settings → The phone. → General information → IMEI.
- 📞 Dial *#06# - the number will appear on the screen.
- 📄 On a box or under a battery.
To verify the IMEI production date:
- Go to IMEI.info.
- Enter your IMEI in the search box.
- In the results, find the line "Date of Manufacture" (if any).
⚠️ Note: Not all databases contain information about the date of production "N/A", Try alternative services like SNDeeP.
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If the phone supports two SIM-He'll have two cards. IMEI (IMEI1 and IMEI2). Check both – they should differ only in the last digit.
3. Date on the box: trust or not?
Many buyers are guided by the date indicated on the Xiaomi box, but there are a few nuances:
- 📅 The date on the box may indicate the date of packaging, not the phone's production. 3-6 months.
- 🔄 Devices from service centers are often repackaged into new boxes.
- 🌍 For global versions (Global) ROM) The date on the box may refer to the time of importation into the region.
Where to look for the date on the package:
- 📦 On a barcode sticker (usually in format) YYYY-MM-DD).
- 🏷️ On the side of the box (only a year may be indicated).
Example of markings on the box Redmi Note 10 Pro:
MANUFACTURE DATE: 2021.03
PACKAGING DATE: 2021.05If the difference between these dates is more than 2 months, this may indicate:
- 🔋 Long-term storage in the warehouse (the battery could degrade).
- 🔄 Repackaging of the device (possibly the phone was in use).
Make sure the serial number on the box and on the phone match|View the date of production (not packaging!)|Check for holograms and protective stickers|Compare the model on the box with the model in the phone settings-->
4. Hidden service codes for date verification
Xiaomi hides some of the technical information behind engineering codes, one that lets you know the date of the first activation of the phone (not production!), which indirectly indicates its age.
- Open the Phone app.
- Enter the code: ##4636###.
- Go to the tab "Phone Information".
- Find the line "Uptime" (working time).
If the phone is new, it will show the time since the first boot, and for used devices, this method is not accurate, since the meter is reset after resetting the settings.
For models on Qualcomm processors (most Xiaomi) the code works:
##225##It displays the calibration date of the battery, which usually coincides with the production date of ±1 month.
⚠️ Note: Not all engineering codes work on POCO And new Redmi models (starting in 2023), and on MediaTek chips, these codes may not work.
5. Check through the official Xiaomi website
Xiaomi provides a tool for authenticating devices by serial number or IMEI.
- Go to the authentication page.
- Enter the serial number or IMEI.
- Fill in the captcha and press Submit.
The system will show:
- 📱 Model of the device.
- 🔍 Authentication (Genuine or Fake).
- 📅 Activation Date (if the phone has already been used).
If a site makes a mistake, “This device does not exist,” it can mean:
- 🔄 Phone is fake (frequent issue with Redmi Note) 8/9).
- 🌍 The device is intended for another region (e.g., the Chinese version for the domestic market).
- 🔧 Serial number erased or damaged.
What to do if Xiaomi does not pass the test?
6.Assessment of battery wear as an indirect indicator of age
If you can't determine the year of release by other means, look at the battery status, and even if the date of production is unknown, the charging cycles and capacity will help you estimate the age of the phone.
How to check the wear of the battery:
- Install the AccuBattery app (available on Google Play).
- Charge your phone to 100% and wait for calibration (1-2 cycles).
- Check out the section “Battery Health”.
| Battery status | Approximate age of the phone | Recommendations |
|---|---|---|
| 90-100% | Less than 1 year | Perfect condition |
| 80-89% | 1-2 years | Normal wear and tear |
| 70-79% | 2-3 years | Replacement is required soon. |
| Less than 70% | More than 3 years | Critical wear and battery dangerous |
For example, if AccuBattery is 75 percent healthy, and the seller claims that the phone is released in 2023, that's a clear mismatch, most likely a 2.5-3 year old device.
⚠️ Note: Xiaomi with removable batteries (e.g. Redmi) 4A, Redmi 5A) The battery could have been replaced, and in that case, the wear and tear doesn't reflect the actual age of the phone.
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If the phone was released more than 2 years ago, but the battery is in perfect condition (95%+), chances are it has been replaced.
7. Buying used Xiaomi: what to look for
When buying a used Xiaomi, the year of release is not the only criterion.
- 🔋 Battery status (see section above).
- 🛠️ Presence of repair marks (check the screws on the case - if they are scratched, the phone was taken apart).
- 🔒 bootloader Unlock Status (Dial ##7378423## → Service info → Configuration).
- 📡 Network support 4G/5G (Especially relevant for Chinese versions).
Typical problems of the old Xiaomi (released before 2020):
- 📶 Poor support for modern LTE-Redmi Note 7 does not catch Band 20 in Europe).
- 🔄 No security updates (devices older than 3 years do not receive patches).
- 🔋 Battery bloating (characteristic of Redmi) 3S, Redmi 4X).
Critical information: Xiaomi phones released before 2019 often have a locked bootloader that cannot be officially unlocked, limiting customization and repair options.