Have you bought a used Xiaomi or are you doubting the honesty of the new smartphone seller? The release date of the device is a key parameter that affects warranty life, battery status and even performance. For example, 2020 smartphones with a battery of 4,000 mAh by 2026 can lose up to 20% of capacity even if they were in stock. And Redmi Note 11 models released in early 2022 often come with fresher chips than the batches of late 2021.
In this article, 5 working ways to know the exact date of Xiaomi production, including methods for devices without a box, with a locked bootloader or custom firmware. We will discuss how to decrypt the serial number, where to look for hidden data in MIUI, and why the information from ##4636## is not always accurate. You will also learn how to distinguish the restyled version (for example, Poco X3 NFC revision 2021) from the original one – this is critical when buying from hand.
Xiaomi serial number decoding: algorithm for all models
Serial number (S/N) — Xiaomi has a major release date source, which is coded according to a standard that has changed. 3 once 2018 year 2018 down 2021, s 2022 Consider the current format (for devices after the 2021 year-end):
Example of serial number: K63B4C9DE78F.
- 📅 4th and 5th characters (B4) — year and month of production. = 2022 (A)=2020, C=2021, D=2023), 4 = spring.
- 🏭 3rd character (3) - factory code (does not affect date, but helps track batch).
- ⚠️ The Last 6 Symbols (E78F) — Unique device identifier (does not carry date information).
For 2018-2021 devices, use a different scheme:
Example: 8QF9C19A06001234
8QF9 → Model (no matter what)
- C → 2019 (B = 2018, D = 2020)
- 19 → Week 19 (May)
A06001234 → unique ID⚠️ Note: Serial numbers Poco and Black Shark can use alternative encoding. F3 The date is encrypted in 6-7 characters, not 4-5 characters.
Find S/N on the box or in settings (Settings → About Phone → General information)
Contrast the format with the table below
Use an online decoder (links in Section 3)
Check the date match with the data from MIUI (section)-->
2.Where to physically look for the serial number (if there is no box)
If the box is lost, the serial number can be found in 5 places:
| Source | Way | Notes |
|---|---|---|
| MIUI settings | Settings → About the phone → General information → Serial number | It works on all models except for custom recavery devices. |
| Slot for SIM | Remove the tray - the number is printed on the sticker below it | Relevant for Redmi 9/10, Poco X3, etc. (not on all models). |
| Battery | Remove the back cover (requires a mediator) | Only for models with removable battery (Redmi 4A, Mi A1). |
| ADB-team | adb shell getprop ro.serialno | Requires USB debugging enabled (Settings → For Developers). |
| Check or guarantee card | Papers from the store. | The date on the check may not coincide with the date of production (think logistics time). |
Important: On Xiaomi models 12/13 series 4 serial number is duplicated by IMEI-sticker under the back panel (visible when illuminated with a flashlight, without disassembling the phone).
On the box | In the phone settings | Under the battery | Through ADB| I don't know where to look-->
3. Online services for decoding the date Xiaomi
If manual decryption causes difficulties, use specialized services:
- 🌐 IMEI.info – enter the serial number in the field S/N Decoder. Shows date, model and region.
- 🔍 Mi-Code – Xiaomi serial number database with history of inspections (helps to identify fakes).
- 📊 SNDeepInfo – analyzes batch and manufacturer (useful for checking originality).
Warning: Services like imei24.com or imei-pro.info often show the wrong date for Xiaomi, as they use universal algorithms that do not take into account the peculiarities of brand coding.
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Before buying a used phone, save a screenshot of the serial number check result, which will help prove the date discrepancy if the seller withheld the information.
Hidden MIUI menus: how to find out the date without a serial number
MIUI's firmware contains the date of first activation and the time of device assembly, to find them:
- Open the Phone app and enter the code: ##4636## Go to the Phone Information tab → scroll to the Opening Time block.
- Or use the code for the hardware test: ##284## Under Version info, look for the Manufacture date line.
Limitations of the method:
- ❌ Poco and Black Shark may not work (use ##6484## instead of 4636).
- ❌ After resetting to factory settings, the activation date is zeroed.
- ❌ On custom firmware (for example, LineageOS) data can be replaced.
What do I do if the codes don't work?
5. IMEI Verification: Myths and Reality
Many users try to find out the release date through IMEI, but this doesn’t work for Xiaomi.
- 🔢 IMEI It only contains information about the model, the country of manufacture and the checksum.
- 📡 Services like imei.info show the registration date IMEI in the base, not the production of the phone (the difference can be up to 6 months).
- ⚠️ On fake Xiaomi (clones) IMEI Often duplicated or replaced, making the test useless.
The only thing you can learn from the IMEI is the originality of the device.
- Enter *#06# and your IMEI will appear.
- Check it out at imei24.com.
- If the model in the results does not match yours, then you are a fake.
Release Date vs. Activation Date: What’s the Difference and Why It Matters
Sellers often confuse (or deliberately substitute) two concepts:
| term | What does it mean? | Where to see. |
|---|---|---|
| Release Date (Manufacture Date) | When the phone rolled off the assembly line | Serial number, hidden menu, sticker on the box |
| Activation Date (First Boot Time) | When the phone was first turned on | Settings → The phone. → Working hours or ADB |
| Date of sale | When you bought your phone in the store | Check, warranty card. |
Why is this critical? Differences between dates may indicate:
- 📦 Warehouse: If the phone was released in January 2023 and activated in December 2023, it was in storage for 11 months.
- 🔄 Resale: Activation date a year older than release date? phone likely already in use.
- ⚙️ Replacement or replacement of fees: if the dates in MIUI And the box doesn't match, maybe the motherboard was replaced.
⚠️ Attention: On Global phones ROM The activation date may be reset when the firmware updates through MIUI bootloader, check it through ADB: adb shell dumpsys battery Look for the line first_install_time.
7. Features for specific Xiaomi models
Some Xiaomi devices have unique ways to verify the date:
- 📱 Xiaomi 12T/12T Pro: Date coded in MEID (analogue IMEI for CDMA). Use the code ##6343##.
- 🎮 Black Shark 4/5: The serial number begins with BSH, where 4–5 symbols - month/year (example: BSHK5... = November 2022).
- 💡 Poco F4 GT: In the engineering menu (#36446337##) there is a Manufacturing Info section with a precise date.
- 🔋 Redmi Note 10/11 Series: Battery sticker shows date in format YY/MM/DD (case: 22/05/15 = 15 may 2022).
For flagships (Xiaomi 13 Ultra, Mix Fold 2), the date can be checked through the official Mi Support app (Device Info section), but this method only works for devices with original firmware and a tied Mi Account.
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If you buy Xiaomi hand-held, be sure to check the date from the serial number with the data in MIUI and on the box. discrepancies of more than 1 month are a reason to be wary.