All Macs have a serial number and each number is unique to a Mac. It’s tied to the motherboard of the computer so, if you happen to have it replaced by Apple, make sure they update the information on your system. The serial number is printed somewhere on your device and a physical examination of the device is all you need to do to find it. On MacBooks, it’s at the bottom towards the back. You can also find the Mac serial number via macOS.
If you don’t want to look for the serial number, you perhaps have a something obscuring it (a tag or sticker), you cannot turn your MacBook over (for whatever reason), or the number has simply faded away with time, you can still find the Mac serial number via macOS.
Find Mac serial number
On your Mac go to the Apple menu and select About this Mac.
In the window that opens, you will see a field for Serial Number. That’s the serial number for your Mac.
Note: the serial number in the screenshot below has been partially hidden. It is 12 characters long and contains both numbers and letters.
Using the serial number
Now that you have the serial number, you might wonder what it’s used for. For one, this is the quickest way to identify your Mac model, especially if you need to look something up related to it on Apple’s website. For example, Apple is offering battery replacement for certain MacBook models. In order to check if your MacBook is eligible, you have to enter its serial number.
If you ever need to contact Apple support online, the serial number will allow whoever is assisting you to get your system configuration quickly.
It can also serve as a low-level anti-theft/ID tool. If you suspect your MacBook’s hardware has been tampered with during repair, you can check its serial number. Likewise, if you know your MacBook’s serial number you can use it to prove a MacBook belongs to you.
We say this is low-level anti-theft because the serial number can be erased. It’s not easy to do so and will require serious changes to the hardware but it is nevertheless possible. If you have anything major on your MacBook replaced, whether it’s by a third-party repair service or by Apple, discuss your system’s serial number with them before hand. Apple will reset it for you though third-party repair services may have a different policy or they may not tinker with it at all.