Quectel Ec25 Change Imei May 2026

| Error Message | Likely Cause | Solution | | :--- | :--- | :--- | | ERROR | Module locked | Use AT+QCFG="imei",1 instead of ,0 | | +CME ERROR: 100 | SIM not inserted | Insert active SIM and register on network | | +CME ERROR: 3 | Operation not allowed | Update firmware to version A08 or newer | | No change after reboot | Write-protect enabled | Use Diag port with AT+QNVW commands | | Checksum error | Invalid IMEI | Recalculate Luhn check digit (15th digit) |

Always check the existing IMEI before making changes. Use:

AT+CGSN=1

Example output:

+CGSN: 123456789012345
OK

Or use:

AT+CGSN

(Returns IMEI without label.)

Make a note of this number. You may need to restore it later.

This is the cleanest method provided by Quectel. It uses the standard Hayes command set extended by Quectel. quectel ec25 change imei

Some older EC25 firmware versions (pre-2019) or custom engineering builds from Quectel allow AT+EGMR. If you have access to such firmware:

Outcome: Simple and reversible. But engineering firmware is rarely available to end customers – only large OEMs under NDA.

Warning: Flashing back to standard firmware sometimes resets the IMEI to factory – or corrupts it entirely. | Error Message | Likely Cause | Solution

Disclaimer: This essay is provided for educational and research purposes only. Modifying the International Mobile Equipment Identity (IMEI) of a cellular device is illegal in many jurisdictions, including the United States (under the Federal Communications Commission regulations and the Wireless Telephone Protection Act) and the European Union. IMEI alteration is frequently associated with fraud, tracking evasion, and the use of stolen devices. The author and platform do not condone any unlawful activity. Readers are solely responsible for complying with all local laws.

If you are on a Linux host (OpenWrt/Raspberry Pi) and only see ttyUSB0: