The tool will provide specific details based on the serial number provided: Valid Serial Number

If you are shopping for a second-hand iPhone or Mac, follow this script to stay safe:

In this detailed guide, we will walk you through every method of running an systems support, decode what the numbers mean, and highlight the red flags every user must know.

If you are looking for the standard operating procedure for checking a device before buying or selling:

On modern Macs and iPhones, the serial number is fused to the security chip (T2 or Secure Enclave). Altering it requires microsoldering and specialized tools—and it is illegal in many jurisdictions.

To check if a device is clean (Find My off), Apple provides a dedicated portal: