Serial number is a character string that includes letters and numerical digits. Your iPhone/iPad's serial number is a unique identifier that distinguishes your device from all of the others. When you are requesting warranty service, it needs your serial number. You may also want to look up your serial number if you're reporting your device stolen. This article describes different ways to find your serial number in different situation.
If your iPhone/iPad turns on, you can find the serial number right in the Settings app.
Step 1: Open Settings app > General.
Step 2: Tap About. You'll see what the serial number of your device.
If your iPhone/iPad is connected with iTunes, you can easily view its serial number.
Step 1: Connect your device to your computer with the included USB cable.
Step 2: Open iTunes, it'll automatically detect your iDevice, and display device icon in its upper left corner.
Step 3: Click device icon. In the left pane of Summary tab, you'll see the information on your device.
If you don’t have access to your device (stolen or lost), you can still find the serial number, here's how:
If you have your product's original packaging, you can check the barcode to find the serial number.
If you have an Apple ID account, the serial number is tied to your Apple ID account online.
Go to the Apple ID account website, sign in with the Apple ID account you used on iPhone/iPad. Click the name of your iPhone/iPad under Devices on the page that appears and you'll see the serial number of your device.