Family travel is no child’s play, especially when taking a plane. Traveling with an infant takes trip planning to a whole new level. What do you do with your stroller, car seat and diaper bag? And don’t forget all the necessary travel documents.

If you’re traveling with United Airlines, we’ve got the details for how to book an infant’s ticket, what kind of baggage allowance you get and even which aircraft have changing tables.

United Airlines infant policy

If your child is under the age of 2 (but older than 7 days old), he or she can sit on a parent’s lap on flights to any destination. However, the cost varies by destination:

U.S. domestic flights (including flights to Puerto Rico and the U.S. Virgin Islands): free, no ticket required.

Flights between the U.S., Canada and Mexico: ticket is required, and you pay only taxes.

International flights (including flights to Guam): ticket is required and charged a partial fare based on the destination.

If you’re flying in United Polaris business class or in economy on select routes, United will provide free bassinets. To request one ahead of your flight, contact United customer service.

If you decide to pay for an infant’s seat, you must bring an approved car seat — as all passengers must be in their seats during takeoff, landing and turbulence. Additionally, children flying in car seats must be in a window seat, and the car seat must be secured to the aircraft seat.

Look for car seats made after 1985, as these are Federal Aviation Administration-approved — and will have a certificate attached to them stating as much. Keep in mind that car seats aren’t allowed in Polaris business class on most Boeing 767, Boeing 777 and Boeing 787 aircraft.

Do I have to pay for an infant’s seat when flying United?

As mentioned above, you don’t have to purchase a seat for a child under 2 if you keep them in your lap for the duration of the flight. However, some situations require you to book a seat for your child.

You book a round-trip flight, and your child turns 2 before the return segment of the itinerary.

You’re an adult traveling with 2 children under the age of 2. You must purchase at least one seat for an infant because you can’t hold more than one child in your lap.

How much will I pay for a lap infant’s ticket on an international itinerary?

The lap infant fare varies based on destination. For example, we’ve looked up a round-trip flight from Newark to Frankfurt in economy class for two adults and one lap infant. The total came to $1,113 per adult, including taxes and fees, and $118 for the lap infant, including taxes and fees. A lap infant’s ticket costs just a fraction of the price of an adult ticket.

When it comes to tickets booked with United MileagePlus miles, you’ll pay 10% of the revenue fare, which includes travel on United as well as on partner airlines. The lap infant fee is capped at $250, which comes in handy if you’re booking a pricey business-class ticket for the parent.

United Airlines stroller policy, carry-on allowance when traveling with an infant

In addition to a regular United carry-on allowance, you may bring the following items onboard when traveling with an infant:

Diaper bag.

Breast pump, milk or formula.

FAA-approved car seat.

Compact folding stroller (must be under standard carry-on limits).

At the airport, you may use standard strollers, folding wagons and car seats to get to your gate and check them for free at the gate.

If you’re nursing, you can breastfeed or pump from your seat or bathroom. You’re also allowed to bring ice to keep the milk and formula cold in the cabin. Unfortunately, you won’t be able to store breastmilk in the onboard fridges, so plan ahead.

Do United planes have changing tables?

The following aircraft feature changing tables in lavatories:

Boeing 757-300.

Boeing 767.

Boeing 777.

Boeing 787.

Select Boeing 757-200.

United Airlines family boarding

Anyone flying with children 2 or younger qualifies for pre-boarding on United planes. Pre-boarding is the first boarding group and also includes the following travelers:

Customers with disabilities.

Unaccompanied minors.

Active members of the military.

Global Services and Premier 1K elites.

How to book a ticket for a lap infant on United

To book an infant’s ticket on United, go to United.com and input your search parameters, including origin city and destination, travel dates and whether you need a round-trip or a one-way ticket.

Under “Travelers,” you’ll be able to select the number of passengers. If you want to buy a ticket with a seat for your child under 2, select “Infants (Under 2).” If you don’t want to purchase a ticket, select “Infants on lap.”

If you’re booking an international trip, make sure your child has a valid passport. For domestic travel, a birth certificate should be enough.

Can I sit together with my child on United?

Parents on a budget might be inclined to book basic economy tickets, which normally don’t include a complimentary seat selection. However, thanks to United’s recent policy, families flying with children under 12 can sit together for free.

So, if you’ve compromised between cost and comfort and purchased a separate seat for your child under 2, you can skip paying for seat selection, even on a basic economy fare.

United Airlines infant policy recapped

Although you don’t have to get a ticket for a lap infant when flying on domestic flights, you need to get one when flying internationally. Luckily, it won’t cost you as much as a full fare, so you can save some money until your child turns 2. After that, your kid will require his or her own seat.

United also offers some great perks for parents traveling with infants, such as priority family boarding, extra carry-on and checked luggage allowance, and free seat selection, even on basic economy fares.