You can still find the number even if you lost the device or are selling it.

Once you have the number, you can use it to look up vital information. There are two primary ways to do this. Method 1: The Official Apple Coverage Check

Before handing over cash for a used iPhone or Mac, run the serial number. If the tool says the device has already been replaced or doesn't match the model being sold, walk away.

Go to Settings > General > About .

If you want to know the exact week your device was made or the specific factory it came from, you can use third-party decoder websites.

To check your official warranty status, use Apple's official tool. Go to the Apple Check Coverage website. Enter your device's serial number. Type in the security captcha code. Click . What you will see:

Finding your Apple device's serial number is the key to unlocking its history, warranty status, and authenticity. Whether you are buying a used iPhone, checking your Mac's repair coverage, or reporting a lost iPad, this unique code is your device's digital fingerprint.

Click the Apple menu () in the top-left corner > About This Mac . Apple Watch: Go to Settings > General > About . Apple TV: Go to Settings > General > About . On the Physical Device (Hardware)