If your family trip is going to include a lot of time in a car, it might make sense to bring your own car seat along instead of struggling with a rental or buying one at your destination. That way, you don't have to worry about struggling with unfamiliar connections and whether the rented car seat is dirty or has non-visible damage that renders it unsafe in a crash. Most U.S. airlines and international airlines will let you take a car seat with you for free, either as checked baggage or as a gate check item.

Checking the Car Seat as Baggage

If you don't want to use your car seat on the plane or while you're in the airport, it makes sense to check it through as baggage; that means one less thing you'll have to carry as you make your way to and from the flight. Cover your car seat with a dedicated car seat cover or a duffel bag to protect it from soil and superficial damage such as broken buckles or torn padding. If you find yourself at the airport without a car seat bag, most airlines will offer heavy-duty plastic bags to use as a makeshift cover. Just like any other piece of baggage, make sure your car seat is marked clearly with your name and phone number or email address that can be used to reach you while you're traveling.

It Can Be Extra Packing Space

For your car seat to travel free, you'll need to show the airline attendant what you have inside that cover or duffel bag – but they generally don't mind if you use the extra space inside or around the car seat to pack a reasonable amount of lightweight child care items like diapers or formula. Just take care not to include any prohibited items or to go overboard with the size or weight of the resulting bundle; it's still subject to airline regulations and healthy common sense.

Gate Checking Your Car Seat

It can be wonderfully liberating to leave your car seat behind at the checked baggage counter – it's one less thing in your hands or dangling from your body as you make your way through the airport. But if you're traveling with a lap infant and want the use of your car seat after security but before the flight, you can also gate check it. Your car seat will still travel in the luggage hold, but you'll be able to drop it off on the jetway as you board the plane; then pick it up on the jetway as you exit the plane. This is especially handy if the car seat would have been the only piece of luggage you'd check through. Just speak to the gate agent before boarding begins and ask for a gate check tag.

Car Seats on the Plane

If your car seat is FAA-approved and your child is traveling in his or her own airline seat, you can generally carry your car seat onto the plane for use there. There have been anecdotal accounts of flight attendants not allowing travelers to use their FAA-approved car seats on the plane, so it's best to carry manufacturer documentation that shows your car seat's approved status, and show it to the gate agent before you board. Here's another bonus of talking to the gate agent before you board: If you were planning to hold your infant in your lap and gate check your FAA-approved car seat, you might even get lucky and be allowed to carry it on if there's an extra seat available for your child.

Tip

As with checked baggage, if your car seat is allowed on the plane, you can usually get away with using it to stash a few essentials like diapers or teething rings. However, just like any other piece of carry-on luggage, it's still subject to the same regulations about what you can and can't bring onto a plane.