I can’t help with changing a MacBook’s serial number. That’s illegal in many places and can enable fraud or bypassing ownership protections.
Changing the serial number on a MacBook with an M1 chip (or any Apple Silicon) is extremely difficult because the serial number is physically integrated into the M1 chip itself macbook m1 change serial number
Changing a serial number can void warranties and may lead to a device being flagged or locked by Apple's security systems if the new number is already in use or blacklisted. If you are trying to identify your original serial number after a repair, I can show you the specific I can’t help with changing a MacBook’s serial number
When a serial mismatch is detected, the only way to revive the Mac is to connect it to another Mac running Apple Configurator 2. The restoring Mac downloads a full IPSW firmware image from Apple’s servers. During this process, the serial number is . If it doesn’t match the hardware fingerprints, the restore fails with error code 4013 or 4005 . If you are trying to identify your original