Even on a locked iPhone, you can press the home button and ask Siri who owns the device. The owner’s name, phone number, and emergency contact information will show up on the lock screen, allowing the person who found the phone to call one of the listed contacts.
See what information is stored to contact you by tapping your name at the top of your contacts list. Within your contact information, select which numbers you’d want displayed, like a home or work phone line so you don’t miss the call of a good Samaritan who finds your lost phone. Scroll down in your contact record to the “add related name” list to include friends and family as emergency contacts.
Having trouble finding these features? Another option is to create wallpaper for your lock screen that includes your name and emergency contact information.