iPhone 5 Serial Number
How can I find my serial number if I cannot boot my device?
iPhone 5, iOS 8.1.1
How can I find my serial number if I cannot boot my device?
iPhone 5, iOS 8.1.1
The following gives some methods: Find the serial number and other information for your iPhone, iPad, and iPod touch - Apple Support
It would also be at https://supportprofile.apple.com/ if you ever added the iPhone to your support profile.
iPhone 5 Serial Number