Finding Your MacBook’s Identity: A Guide to Locating Your Serial Number
System Settings: Open System Settings (or System Preferences), go to General, and select About.
If your MacBook won't turn on, you can find the number physically:
Pro Tip: Once you have your serial number, you can verify your warranty status by entering it at the Apple Check Coverage site.
Checking the serial number on your MacBook Pro is simple, whether the computer is powered on or off. The fastest way is Apple menu at the top-left of your screen Apple Support For a Working MacBook Pro About This Mac (Easiest) : Click the Apple menu () and select About This Mac
Original Box: Look for a barcode label on the original product packaging; the serial number is typically listed there.
If your screen is broken or the laptop won't power up, check these physical locations:
Original Packaging: If you still have the box, look for the barcode label on the side or bottom; the serial number is printed next to the barcode.