How to accurately determine the date of manufacture of the Xiaomi phone: from the box to hidden codes

Did you buy a used Xiaomi Redmi Note 12 or POCO X5 Pro at a bargain price, but doubt the honesty of the seller? Or do you want to check whether you sold a “fresh” smartphone from the counter, which actually lay in the warehouse for 3 years? The date of production of the phone directly affects the battery life, warranty obligations and even the market value of the device.

In this article, we’ll look at all the official and hidden ways to know when your Xiaomi was released, from serial number analysis to engineering menus, learn how to distinguish fake data on the box from the actual build date, and understand why some methods don’t work for all models. Instructions are relevant for smartphones 2018-2026, including the Redmi, POCO, Mi and Black Shark lines.

1. Serial number check (S/N) — most reliable

The serial number (S/N) is your phone’s unique identifier, which contains coded production date information. Xiaomi’s serial number format has changed over time, but in most cases, the date can be extracted from the first 4-6 characters.

Where to find the serial number:

• 📦 On a sticker under the removable lid (for models with removable battery, for example, Redmi). 4A)
• 📱 In settings: Settings → The phone. → General information → Serial number.
• 🔋 On the battery (if it is removable)
• 📄 In a check or warranty card (if retained)

How to decipher the date:

• 🔢 Format 2018–2020: First 4 Numbers are a year and a week: 1935 = 35-I'm a week. 2019 year).
• 🔢 Format 2021–2026: First 3 the symbol - the factory code, the following 3 — year/week. Example: ABC9K2, where 9K2 = 2-I'm a week. 2019 year (but requires additional decryption).

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Attention! Some vendors fake serial number stickers on boxes. Always check the number on the box against the data in the phone settings. If they don't match, you're either a fake or the phone has been replaced under warranty.

2.IMEI Analysis: What You Can Learn About Release Date

IMEI (International Mobile Equipment Identity) is another unique identifier, but it does not contain direct information about the date of production, but IMEI can indirectly determine the age of the phone through verification services.

How to check for IMEI:

1. Dial on the phone keyboard *#06# - a window with a 15-digit number will appear.
2. Go to IMEI.info or SNDeeP and enter the number.
3. Look at the date of first activation (not to be confused with the date of production!) If the phone was in stock, the difference could be 6-12 months.

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Limitations of the method:

• ⚠️ Services show the date of first network link, not production.
• ⚠️ For new models (2023–2026), data may not be available.
• ⚠️ Some operators (e.g. China) do not transfer data to global databases.

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If IMEI starts with 86, the phone is assembled in China, and it starts with 35 in Europe or India, which doesn't affect the date, but it helps to identify the "gray" shipments.

3.Date on the box and stickers: trust or not?

The manufacturer shall place the production date on three places:

1. A sticker on a box (usually on the end or bottom) format: YYYY-MM-DD or WW-YY (week-year).
2. Sticker under the battery (for models with removable battery).
3. Sticker on the tray SIM-cards (rarely, but found in the POCO F1 Mi 8).

Examples of real labels:

Warning!: Fraudsters often forge stickers on boxes, especially for popular models (Redmi Note 11, POCO F3).

⚠️ Compare the date on the box to the serial number in your phone settings. If the difference is greater than 3 months, you're either a fake or the phone has been replaced under warranty.

4 Hidden engineering menus: how to find out the date without disassembly

Xiaomi phones have hidden menus where you can find information about the date of production, which methods do not work on all models, but it is worth a try.

Method 1. Testing menu (#4636###)

1. Open the Phone app and type ##4636##.
2. Go to the tab Information about the phone.
3. Scroll down to the Build Date or Build Date block.

Method 2: MIUI menu (##225###)

This code runs on MIUI firmware 12-14:

1 Enter ##225##


2. Select "Version info"




3. Find the line "Manufacture date"

5. Check through official Xiaomi services

Xiaomi provides two official authentication and production dates:

1.Authentication Service (mi.com/verify)

• 🔍 Enter. IMEI serial number.
• 📅 The system will show the date of the first activation (not production!).
• 🔄 For new phones, the difference between production and activation is 1-6 months.

2.The Mi Verify app (China only)

This app is available on the Chinese App Store and requires registration, and it shows the full history of the device, including the build date, but only works for phones sold in China.

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Xiaomi’s official services DO NOT show the exact date of production – only the date of first activation. To find out the real age of the phone, combine the methods from this article.

6. Indirect signs: how to determine the age of the phone without codes

If none of the above methods worked, pay attention to the physical and programmatic features:

Battery:

• 🔋 Phones older than 2 years have a 15-30% battery capacity drop. → Battery → Battery status.
• 🔌 If the phone is discharged in 3-4 hours with an average load, it is definitely more than 18 months old.

Body and equipment:

• 📦 Xiaomi boxes were gray with red accents until 2020. Since 2021, they are white with minimalist designs.
• 🔌 Charging units older than 2021 have power 10W or 18W. New models (2022–2026) — 33W, 67W or 120W.

Firmware:

• 🤖 Phones 2018-2019 were often supplied with MIUI 10 or Android 9.If your Redmi Note 7 is still on MIUI 11 - it hasn't been updated 3+ year-end.
• 🔄 Check the date of the last update in Settings → The phone. → Updating the system.

7 Frequent Mistakes: Why Methods May Not Work

Not all methods of determining the date of production are universal, but here are the common reasons for failure:

Attention! On custom firmware phones like LineageOS or Pixel Experience, all the system methods for verifying the production date don't work, so you only have to analyze the serial number or IMEI.

FAQ: Answers to Frequent Questions