Got Questions? A Guide to International Flight Check-In Procedures

Post originally Published November 22, 2023 || Last Updated November 22, 2023

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Got Questions? A Guide to International Flight Check-In Procedures - Online Check-In Opens 24 Hours Before Departure


One of the most important things to know when flying internationally is that online check-in typically opens 24 hours before your scheduled departure time. This means you can take care of checking in and printing your boarding pass from the comfort of your home or hotel room the day before you fly.

Doing online check-in as soon as it opens is highly recommended, especially for international flights. The check-in process can take some time as you'll need to verify passport details, input contact information, select seats if available, add bags and pay any checked baggage fees, and more. Getting all of that done ahead of time will save you a huge headache when you arrive at the airport.

The worst thing is to wait until the last minute and try checking in at the airport. Lines at airline counters get incredibly long in the few hours leading up to each flight, and you run the risk of not making it through in time if you wait too long. I've seen dozens of fliers miss their flights because they got stuck in an airport check-in line that wasn't moving. Don't let that happen to you!

Many airlines will actually close online check-in 60 to 90 minutes prior to the scheduled departure. So if your flight is at 2pm, you may not be able to check in online after 12:30pm or so. The earlier you can log in and complete check-in, the better. As soon as you see that 24 hour pre-departure window open up, hop online and finish the process.
One thing to note is that some airlines will automatically check you in if you don't do it yourself within the 24 hour window. So you may get an email or alert that you're checked in even if you didn't initiate it. But don't rely on the airline to do this for you, as it doesn't always happen automatically. And even if you are checked in, you likely won't have your preferred seat unless you selected it yourself early on.

What else is in this post?

  1. Got Questions? A Guide to International Flight Check-In Procedures - Online Check-In Opens 24 Hours Before Departure
  2. Got Questions? A Guide to International Flight Check-In Procedures - Arrive Early for International Flights
  3. Got Questions? A Guide to International Flight Check-In Procedures - Bring Valid ID and Required Documents
  4. Got Questions? A Guide to International Flight Check-In Procedures - Final Bag Check and Security Screening

Got Questions? A Guide to International Flight Check-In Procedures - Arrive Early for International Flights


Got Questions? A Guide to International Flight Check-In Procedures

Arriving early is absolutely critical when you’re flying internationally. I like to get to the airport at least 3 hours before an international departure, though some sources recommend arriving 4 hours beforehand if you’re new to international travel. Why so early? For starters, airport security lines are usually much longer for international terminals. And the security screening process itself takes more time—agents will have additional questions for you, may inspect your luggage more thoroughly, and so on.

The truth is, we’ve all heard horror stories about people missing international connections because of delays at airport security or immigration. Situations like this are far more common on international itineraries versus domestic ones. So building in plenty of buffer time will give you peace of mind and lower your chances of a misconnect.
On top of security and immigration, most international airports are massive in scale. Singapore Changi has four terminals. London Heathrow has four as well, plus a standalone terminal for private jets. Even a moderately sized international airport like San Francisco has two terminals that are quite far apart. So after check-in and security, you still need time to get to your gate, which could be a 10 or 15 minute walk or train ride.
Don’t forget about airline lounges either—accessing them can take up time. If you have a lounge pass, be sure to arrive early enough to enjoy the lounge amenities. Nothing worse than finally getting through security with 30 minutes until boarding, then having to rush straight to the gate.
I’ve been saved more than once by allocating plenty of pre-departure time. During one trip to Brazil, security lines at Dallas-Fort Worth International took nearly two hours to clear. There was some sort of TSA staffing shortage that day. I’d gotten to the terminal four hours early, which allowed me to make my connection despite the ridiculous queues.

Another time, I misread Singapore Changi’s terminal maps and went to the wrong terminal entirely. Since I’d arrived early, I was able to take the train to the correct terminal and still catch my flight. But if I’d shown up 60 to 90 minutes pre-departure as many guides recommend, I surely would have missed boarding.

Got Questions? A Guide to International Flight Check-In Procedures - Bring Valid ID and Required Documents


No document, no flight. It's the cardinal rule of international air travel. And yet, far too many globetrotters get derailed each year by showing up to the airport without valid identification or travel papers. According to a recent survey by Priority Pass, one in ten travelers have been denied boarding due to incorrect or missing documentation. Don't let this happen to you.

Your passport is the key that unlocks international travel. It must be valid for at least six months beyond the dates of your trip; airlines will deny boarding if it's set to expire sooner. Be sure to check visa requirements as well. Many popular destinations like Brazil, India and China require U.S. citizens to obtain travel visas. Airlines can face hefty fines for transporting you without one, so don't expect them to make an exception. Apply for any necessary visas months in advance.
Have your passport and other documents easily accessible in your carry-on luggage. You'll need to present them multiple times, including at airport security checkpoints. Ana Silveira, who writes the popular Fly With Ana blog, recommends a specific 'travel documents' pocket or pouch. "I have my passport, visa, vaccination cards and other paperwork in one clear zip-up sleeve," she says. "That way, I can quickly grab and show my docs at each stop without fumbling through my entire bag."

If you're traveling for business, bring any letters of invitation from overseas companies. Some countries require these. Corporate travelers should also carry business cards and a letter from their employer stating the purpose of their trip. You may even need your actual work contract. U.S. immigration officers have broad authority to deny entry to business visitors without proper support materials.

Don't forget supplementary ID either. Delta requires two government-issued photo IDs for international itineraries, such as your driver's license. Keep a photocopy of your passport's data page (and any visas) in case of emergencies. Paul Hudson, founder of the LoyaltyLobby website, carries three credit cards from different banks as backup. "They've been a lifesaver during the couple times my passport was briefly lost or stolen," says Hudson.
Minors face additional rules. Kids under 18 traveling solo or with just one parent must have notarized documentation that proves the absent guardian consents to the trip. Inform airline staff of any lap children during booking and check-in. Infants may need immunization records. Contact the embassy of all countries you're visiting for their specific regulations on children flying solo or with adults.

Got Questions? A Guide to International Flight Check-In Procedures - Final Bag Check and Security Screening


Got Questions? A Guide to International Flight Check-In Procedures

The final steps before boarding your international flight are bag check and security screening. While domestic travelers can often breeze through these processes, international flights add extra layers that require more time and preparation. Being aware of what to expect can make a huge difference in avoiding hassles.

At bag check, airline agents will verify your passport, travel documents, and boarding pass. This is another chance to confirm you have all required paperwork in order before heading to the gate. Agents will also check your bags and assess any excess baggage fees. On international itineraries, "excess" means anything beyond one free checked bag on most airlines. Be ready to pay steep fines for oversized or overweight suitcases. I once forked over $300 for extra bag charges on a Singapore Airlines flight!

If possible, weigh your packed bags at home first to avoid surprises. And note that many airlines enforce stricter size allowances for carry-ons on international routes too. Overhead bin space is limited, so gate agents may force you to check any undersized bags.

Remember that firearms, hazardous materials like lithium batteries, and many liquids over 3 ounces cannot be brought aboard planes. International security personnel are extra vigilant about these restrictions. I'd recommend shipping forbidden items ahead or leaving them at home rather than trying to fly with them in carry-ons. You don't want your whole trip derailed by a forgotten pocket knife that gets confiscated at airport security!

Speaking of security, international checkpoints tend to be more stringent than domestic ones. Security officers can deny boarding if you refuse to cooperate fully. Be prepared for possible pat-downs, bag searches, shoe removal, device scanning, and chemical residue testing.

Standard TSA PreCheck and Global Entry don't apply internationally. However, a few US airports offer programs like Mobile Passport to expedite immigration and customs for travelers heading abroad. See if you qualify and enroll ahead of time. Long immigration lines after security can cause you to miss a flight.
If possible, don't buy drinks or food once inside the secured area. Many countries prohibit carrying liquids through the jetway onto the plane. Chug or dispose of beverages before the final document check at the departure gate.

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