I usually don't have to wait much to go through the U.S. transportation and security administration line at airports where Clear and TSA PreCheck are available.

Even though I fly out of airports and airlines offer expedited security, I still arrive at the airport earlier just in case something unforeseen happens.

Unusual circumstances can result in a later-than- planned arrival at the airport for travelers like me.

An unexpected, nearly hourlong ride to Los Angeles International Airport (LAX) had me worried about navigating security at the airport since the airline I flew doesn't participate in the Clear program.

I was wondering how late I could get to the gate without missing my plane as I waited for security to let me through.

Most airlines have standard check-in time requirements that are different for domestic and international flights.

This is the most recent time you can check in at the airport and still get a boarding pass, but you need to consider how late you can get to your gate.

Check-in and gate arrival requirements are detailed in this guide.

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Alaska Airlines

All Alaska Airlines passengers must check in for their flight no later than 40 minutes before domestic flights and one hour before international flights.

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Travelers are advised to check their bags at the airport before the cutoff time if they want to have their bags turned over in time.

Alaska flyers should be at the gate 30 minutes before their flight.

Being late may cause the cancellation of your reserved seats.

American Airlines

The exact boarding time for AA flights varies from destination to destination.

The boarding ends 15 minutes before the flight leaves. Most domestic carriers use this 15-minute gate closing time.

If you aren't on the plane, we can reassign your seat. Once the doors close, you won't be allowed to board.

You need to check in at least 45 minutes prior to your flight for flights within the U.S. and an hour for international flights.

Delta Air Lines

Delta passengers have to check in at least half an hour before their flight and be at the gate at least 15 minutes before their flight.

The minimum check-in time for international flights is one hour before departure, while Delta requires you to be at your gate 45 minutes prior to your flight.

JetBlue

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Passengers on international flights can arrive at the gate up to 20 minutes before departure, which is the most generous international check-in policy of all the carriers mentioned in this guide.

If you experience a delay between checking in and arriving at the gate, the 20-minute window before boarding won't apply. International passengers can check their bags at the airport for 60 minutes. All other bags must be checked at the airport.

If a boarding pass isn't marked, what to do?

Southwest

Southwest is the most generous with its check in policy. Customers can board all the way up to 10 minutes before their flight leaves.

All passengers are encouraged to arrive at the gate no later than 30 minutes before their flight.

United Airlines

United has the most varied check in policies for travelers based on the route.

  • For most United- and United Express-operated domestic flights, travelers not checking bags must check in for their flight at least 30 minutes before departure.
  • For most United- and United Express-operated domestic flights, travelers with checked luggage need to check in at least 45 minutes before departure.
  • For most United- and United Express-operated international flights, travelers must check in at least an hour before departure, regardless of whether they are checking luggage.

All customers need to be on board the aircraft 15 minutes before the scheduled departure time for flights within the US.

"We recommend being at the boarding gate at least 15 minutes before departure to ensure that you are on the aircraft before the doors are closed," said United. You should be at the gate no later than 30 minutes before your flight.

Bottom line

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Airport requirements for travelers about the latest time you can arrive at the airport without missing your flight are included in the above policies.

Most U.S. airports require passengers to check in at least 30 minutes before their scheduled departure time, regardless of whether you check a bag.

All passengers flying out of Toronto Pearson Airport must check in 90 minutes before their flight, while those leaving from Amsterdam Airport Schiphol must check in 75 minutes. To verify the minimum check-in time at an airport, you should contact it directly.

Most airports require you to check in at least 45 minutes before your flight, but JFK requires passengers to check in 60 minutes before their flight. If you are like me and don't mind checking a bag, you should be able to get to the airport within 30 minutes for domestic flights and one hour for international flights.

If you find yourself in a long security line, at risk of missing your flight, please ask the relevant airport security employee if you can skip ahead in line. I've seen people do this before and the agent at the airport helps them.

Sometimes travel days don't go as planned. You should review the minimum requirements for the latest time you can check in for your flight and arrive at your gate.

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