It is crucial to note the line between repair and fraud . Restoring a phone’s IMEI is a legitimate repair, often saving a device from the landfill. However, "Repairing" an IMEI by changing it to a different number (often stolen from another device) is illegal in most jurisdictions. A true repair aims to restore the factory identity, not fabricate a new one.

If the IMEI is null or invalid after a custom ROM installation or a failed flash, technicians often use specific service tools. These usually require a Windows PC and a USB cable.

: This is a common professional tool that supports MediaTek and Qualcomm-based Sony devices. It requires connecting the phone in a specific "service mode" (often by holding Volume Up/Down while plugging in the USB) to "patch" or repair the IMEI using a valid number from the device's sticker or box. Octoplus Pro