How to Restore IMEI on Android After Reflashing?

Every Android device comes with IMEI or International Mobile Equipment Identity. Think of it as your phone’s fingerprint: a special 15-digit serial code number assigned during production that identifies the phone regardless of the SIM card.

Why is the IMEI important? The importance of IMEI is directly correlated with its wide range of practical uses. The unique identifier makes IMEI crucial in several situations, including:

• Identification. IMEI is your device’s fingerprint that distinguishes it from other phones. The unique identifier comes in handy for manufacturers and users who can differentiate their phones from the crowd.
• Tracking. One of the main perks of IMEI is that it simplifies the search if your device is stolen or lost. Whether you’re filing a report with law enforcement or calling your carrier provider to blacklist it, providing your device’s IMEI will simplify the search.
• Blacklisting. If reported lost or stolen, the network provider can blacklist the phone in the shared database of stolen devices, which blocks it from the other carriers. Basically, you can't use the phone for any phone calls, messaging, or cellular data.

What Do the IMEI Numbers Mean? The 15-digit code can be grouped into three smaller categories. The first 8 numbers are the device’s type allocation code, identifying the manufacturer and the specific model. The next 6 digits represent the device’s serial number, while the last number is a check digit, which verifies the integrity of the entire IMEI.

What’s the Difference Between ESN, IMEI, and MEID? The terms are often grounds for confusion, as all three are used to identify a device uniquely. Here’s a look at the key differences:

• IMEI (International Mobile Equipment Identity) is typically found in devices that rely on GMS technology and SIM cards for authentication.
• MEID (Mobile Equipment Identifier) is mostly used by older models that rely on CDMA technology that uses the mobile’s unique identifiers.
• ESN (Electronic Serial Number) was gradually replaced by the MEID as the manufacturers exhausted the unique number combinations. ESN is used mostly by CDMA carriers.

Mind you, the mobile phone can’t support both technologies at once, which makes the device either GSM- or CDMA-based.

Finding out that the IMEI is lost after flashing is pretty straightforward: you’ll receive the Invalid IMEI Number error message printed across the device screen. To fix the error and move your IMEI from invalid to restored, figure out the old number linked to the firmware. Here are a couple of ways to achieve it:

1. Dial *#06#. One of the easiest ways to check the IMEI is to dial *#06#, after which you’ll automatically receive the number on the screen. Dual-SIM phone owners will get two IMEI numbers.
2. Phone Settings. Android users will find the IMEI number in Settings > About Phone section.
3. Retail Box. Your device’s original packaging typically has the IMEI number on it.
4. SIM Card. Although not all Android phones have this option, it’s still worth ejecting the SIM card tray to check whether it features the IMEI code.
5. Network Provider. Call your carrier for detailed information. Customer support will guide you through the process.
6. Google Services. There are two ways for Android users to check the phone’s IMEI: First, open Google Dashboard, select the smartphone, and click on the information icon; second, open Google Find My Device and tap the top left information icon.

Luckily, even if you’ve lost the IMEI, there are numerous ways to retrieve it, even if you don’t have access to your phone.

After finding the number, it’s high time to replace it. Here, we’ll look at how to do it through the engineering menu, a hidden Android menu that gives access to hardware information and setting modifications like registering IMEI information, camera customization, etc.

How to Access Engineering Mode? There are two approaches: you can download a specific engineering mode app or input a code tailor-made for different phone brands. Before doing any of the mentioned procedures, you need to root your device.

• Samsung: Open the calling app > enter * # 0011 # > tap three dots in the upper right corner > click Key Input > enter Q0 in the mini pop-up window.
• Sony: Open the calling app > enter * # * # * # * # 7378423.
• Xiaomi: Open the calling app > enter * # * 6484 * # * > in the pop-up menu, enter * # * # 64663 # * # *.
• Huawei: Open the calling app > enter *#* #2846579 #*#*.
• OPPO: Open the calling app > enter * # # 36446337

While in engineering mode, scroll through the navigation bar and click on Connectivity > Information about CDS > Radio information. At the AT+ line, your input should look like this:

AT+EGMR = 1,7, «XXXXXXXXXXXXXXX»
Replace the X with your IMEI number.