Here are seven things you might not have known about your passport:

Fall is the best time to renew your passport. 
If you obtained your passport after age 16, it’s valid for 10 years.  If before, you get 5 years.  As some countries require at least six months beyond your travel dates to enter, it’s always wise to keep tabs on your family’s expiration dates. The best time to renew is in fall when applications are at a low before Thanksgiving and holiday rushes, the State Department says. You’ll likely get yours processed faster.

You can get an XL passport with extra pages — for free!
The traditional U.S. passport comes with 28 pages, but you can request a 52-page one for free when you apply for your first passport or renew an old one. You can also add pages to an existing passport, but for an $82 fee.

What is a passport card?

It’s wallet-sized and it costs less than a regular adult passport. But you can only use it to re-enter the U.S. from land border-crossings and sea ports of entry in Canada, Mexico, the Caribbean and Bermuda.

Your passport is one of the most powerful in the world.
If you’re from the U.S., your passport affords you free access to 172 other countries. Not many other global citizens can say the same.

If you got your passport after 2007, there’s an electronic chip in it. 
That chip on the back stores the same personal information printed on your passport’s photo page, plus a biometric identifier (aka a digital image of your face). If you have one of these “e-passports,” agents can use facial recognition technology to confirm the passport is indeed yours.

You don’t have to take your passport photo at the drugstore.
The picture must be square, unaltered and on a white background, but you’re allowed to take it at home.  Check http://travel.state.gov/content/passports/english/passports/photos/photos.html for details.

You may get barred from boarding if your passport doesn’t have enough blank pages.
“Some countries require that your passport has two to four blank visa/stamp pages,” reads the State Department website. “Some airlines will not allow you to board if this requirement in not met.”  Always check the requirements for your specific destination before you go.