You fly with one all the time and most of you don’t pay any attention to it once you board the plane.

It’s your boarding pass. You know…the one you often leave in the seat back pocket when you deplane.

But it’s not just the boarding pass that’s important—it’s the boarding pass bar code, and what you don’t know could hurt you.

So what’s in that Bar Coded Boarding Pass (BCBP)?

Well, it turns out it holds a lot of information about you.

It includes your future travel plans, onward flights, and confirmation code, which when accessed, can reveal your entire account with an airline.

That includes your home address and phone number.

It’s better to be safe than sorry.

Keep your boarding passes with you, even on flights you’ve already taken.

Then, unless you want to keep them as a souvenir, cut them into many pieces or put them through a shredder when you return home.

For more information about boarding and travel security, check out:

• How to Store Your Boarding Pass on Your Phone
• Preclearance Will Expand to 10 International Airports
• Global Entry vs. TSA PreCheck: Which Is Worth It?

Keep reading for more travel tips.