What's My Serial Number?

You may be asked to provide your Mac's serial number. It is usually written on the base of your Mac in very small letters, but you can also find it out from your booted system. Here's how to find it out:

OS X El Capitan

Click on the Apple symbol (top left of the task bar), and select "About This Mac”. The serial number is quoted on this page, like so:

OS X Mountain Lion and Mavericks

Click on the Apple symbol (top left of the task bar), and select "About This Mac”.

Then, click on the writing that says "Version 10.X.X" twice to reveal the serial number: