How to check serial number OS X Mavericks or earlier.

How to check serial number OS X Mavericks or earlier.

1. Choose About This Mac from the Apple menu.
2. Double-click the version number to reveal your computer’s serial number.
   
   

Using System Information

You can also find your computer’s serial number in the Hardware section of System Information. To hear your Mac speak its serial number, open System Information and press Command-4.

Cr : https://support.apple.com/en-us/HT201581