Do Grandparents Need a Letter to Travel With Grandchildren?

"They're asking for a letter. Did you give me a letter?" That's the phone call no grandmother wants to make from a cruise terminal. Two kids beside her, two little roller bags covered in stickers, and their parents already through security at an airport three states away. I'm a grandmother, and I hear versions of this worry from women my age all the time, usually about a week before the trip.

So, do grandparents need a letter to travel with grandchildren? If you're flying inside the U.S., most of the time nobody asks for one. If you're boarding a cruise ship or crossing a border, bring one. It's a single page, signed by the parents and stamped by a notary, that says the kids are traveling with you and you can okay medical care. It might be the cheapest thing you pack.

I didn't want to guess on this one, so I read what the government and a major cruise line say in their own words.

Do grandparents need a letter to travel with grandchildren? What the rules say

Start with the federal government. USA.gov's page on travel documents for children says that when a child leaves the country with a guardian or alone, both parents should sign a letter of consent. It even hands you the sentence: "I acknowledge that my child is traveling outside the country with [the name of the adult] with my permission." It also says the letter is preferred in English and notarized.

Notice the word "should." Nobody is promising to stop you at the gate without it. An airline agent or a border officer can still ask, and that's reason enough for me to carry one.

Cruise lines are stricter. Royal Caribbean's policy says an adult who isn't the parent or legal guardian has to present "an original, notarized letter signed by the child's parent(s)." That letter has to authorize you to take the child on that specific cruise, supervise them, and allow emergency medical treatment. Other lines write it their own way, so look yours up before you make the final payment.

This catches Alaska travelers too. Plenty of Alaska sailings start in Canada or stop there, which means the kids are leaving the country. If Alaska is on your list, I worked out what an Alaska cruise really costs for two, and adding grandkids changes that math fast.

Domestic flights are the easy one. TSA doesn't require ID for kids under 18 flying within the United States, and I couldn't find a federal rule that makes Grandma carry a permission slip to Chicago. Airlines can set their own policies, so check with yours. I'd still carry the letter, and the next part is why.

The medical line is the part I wouldn't skip

Imagine day three of the trip. Your grandson slips at the pool and his wrist swells up like a tennis ball. Now you're at an urgent care front desk, his parents are six time zones away with their phones off, and the woman behind the glass wants to know who can consent to treatment.

One sentence in that letter answers her. Something like: "We authorize [your name] to consent to any routine or emergency medical treatment for our child during this trip." Royal Caribbean builds that kind of authorization right into its sample letter. I'd put it in every version, cruise or no cruise.

Tuck copies of the kids' insurance cards behind it, front and back, with the pediatrician's phone number and a short list of allergies and medications. You'll probably never open it. I'd want it anyway.

What I'd put in the folder

One cheap plastic folder, and it stays in your carry-on the whole trip.

• The consent letter, with each child's full name and birth date, your name the way it appears on your ID, where you're going, and the dates. Both parents sign it and add their cell numbers.
• The medical authorization sentence, in that same letter.
• The original notarized copy, two photocopies, and a photo of it on your phone.
• Copies of the kids' birth certificates. If your last name is different from theirs, this is the paper that connects you.
• Passports for anything outside the U.S. Look at the expiration dates tonight.
• Insurance cards and the pediatrician's number.

About those passports. A child's passport is only good for five years, and the State Department lists the cost at $100 plus a $35 acceptance fee as of October 2026. Routine processing runs four to six weeks, and that's before mailing time. Both parents have to be part of that application, so this errand belongs to them. Ask about it now.

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Getting it notarized without making it a project

The parents sign in front of the notary, so tell them to leave the signature line blank until they get there. Plenty of banks notarize for their own customers at no charge, and shipping stores and online notaries do it for a small fee. Figure about twenty minutes.

I'd write a fresh letter for every trip, with that trip's dates on it. I wouldn't hand an agent a vague one from last summer.

If the parents are divorced or share custody, get both signatures anyway. That's what USA.gov recommends, and it heads off the hardest conversation you could have at a counter.

Will a grandkid trip cost more than you think?

Yes, and the school calendar is why. I've written about why I travel in shoulder season now that my schedule is my own. Grandkids are the exception. They're free at Thanksgiving, over Christmas, during spring break and all summer, and those are the priciest weeks of the year.

So book early. If Thanksgiving is the plan, this is when I'd book those flights. Then price the room in more than one place before you pay, because I've seen big gaps on the exact same room. One of the places I check is Travel Advantage. I'm an MWR Life ambassador and earn a commission if you join through my link.

The phone call that never happens

Back to that cruise terminal. Same kids, same sticker-covered bags. The agent asks for the letter, and this time Grandma slides a plastic folder across the counter. The agent glances at the notary stamp and waves them through.

The only thing she sends the parents that day is a photo of two kids on the top deck, already arguing about who gets the top bunk.

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Grandparent travel letter FAQ

Does a travel consent letter for grandparents have to be notarized?

USA.gov says notarized is preferred, and Royal Caribbean asks for an original, notarized letter. I'd notarize it every time. It takes about twenty minutes, and it's the version I'd want in my hand at the counter.

Do grandparents need a letter for a domestic flight with grandchildren?

Usually nobody asks. TSA doesn't require ID for kids under 18 on flights within the United States, though your airline may have its own policy. I'd still bring the letter because of the medical authorization.

Do both parents have to sign the letter?

USA.gov says both parents should sign when a child travels with a guardian or alone. If one parent can't, ask your cruise line or airline what they'll accept before you travel. For a complicated custody situation, talk to a family attorney.

How long is a child's passport good for?

Five years for kids under 16, so the one from the last family trip may have expired. As of October 2026 the State Department lists $100 for the passport book plus a $35 acceptance fee, and routine processing takes four to six weeks before mailing.

I'm not an attorney, and requirements vary by cruise line, airline and country. Confirm the rules for your exact trip before you go.