Most people have no idea how much personal information is actually present on their airplane boarding pass when they fly.

It is fairly common to see people post photos of their plane tickets in their excitement about their trip, or they might leave the ticket somewhere unsafe after they’ve arrived. Many people simply leave their ticket in their seat, or crumple it up and throw it away at their first convenience.

This may seem like an unimportant piece of paper after the flight, but it is anything but that.

There isn’t much information printed directly on the ticket. Most plane tickets are simple pieces of thin card material with the passenger’s most pertinent flight info printed on the side. There will be a seat number, a flight number, a flight time, the passenger’s name, and any other vital tidbits.

However, there is much more hiding in plain sight. The ticket also includes a barcode printed on the bottom, and the barcode contains much more information than you might think.

That single barcode on the plane ticket can hold the passenger’s home address, email address, phone number, and just about any other piece of information collected by the airline during the booking process. In fact, the only piece of information that isn’t available on the ticket is the credit card number used to purchase the seats.

However, hackers have an easy time stealing your identity with the few pieces of info they could clean from the discarded barcode, so be careful what you do with your old plane tickets.