Locate the serial number on an Apple Macbook in the software, on the surface of the unit, on the packaging or on the receipt. The exact location on the unit differs depending on the model and year of manufacture.
Find the serial number on both the Macbook Air and Macbook Pro in the About This Mac window by selecting About This Mac from the Apple menu. On Mac OS X Yosemite, the serial number is just above the System Report and Software Update buttons. On Mac OS X Mavericks and earlier versions, double-click the version number to view the serial number, or click the More Info button.
On Macbook Airs, locate the serial number on the back of the unit near the regulatory markings. The serial number appears below the markings or to the right and just above them.
On Macbook Pros, find the serial number on the bottom of the case just after the copyright information or below the agency approval symbols. If you are unable to locate the serial number, it may be inside the battery compartment. Turn off the computer, and remove the battery. Locate the serial number on the front wall or on the bottom of the battery bay.
The serial number also appears on the original packaging’s barcode label and on the receipt or purchase invoice.