Making sure you’ve packed everything, brought your passport or ID, your baggage isn’t over the weight limit, you adhere by TSA’s 3-1-1 Rule for liquids in your carry on… it’s safe to say that the day of a flight can be a very stressful experience.

Many passengers therefore like to check in early to put their mind at ease. It’s just one less thing to think about.

If this sounds like you, you might be wondering how early you can check in for a flight.

Generally, airlines allow you to check in online up to 24 hours before the scheduled departure time – and 1 hour before at the very latest.

If checking in at the airport counter, and you have baggage you want to check, you can usually check in 3-4 hours before your flight. For domestic flights, this may reduce to 3 hours.

Checking into a Flight Online

It’s no coincidence that the earliest you can check in for a flight is always through online means – whether that be through the airline’s website or app.

  • Alaska Airlines

If checking in online with Alaska Airlines, you can check in anywhere from 1 to 24 hours before your flight.

  • American Airlines

According to American Airlines, you can check in online or from their app starting 24 hours before and up to 45 minutes before departure (90 for international flights).

  • Delta

Delta allow passengers to check in online up to 24 hours before departure.

  • Frontier

Frontier state that you can check in up to 24 hours before your flight (and until 60 minutes prior to departure).

Hawaiian Airlines

Hawaiian Airlines online check in is available 24 hours prior to your flight’s departure

  • JetBlue

If done online, can check in for your JetBlue flight up to 24 hours before departure

  • Southwest

Southwest state that passengers can check in online 24 hours prior to their scheduled departure.

  • Spirit

With Spirit Airlines, online check in begins 24 hours before departure and ends an hour prior to departure

  • United

United allow you to check in up to 24 hours before your scheduled departure time

Domestic vs. International Flights Check In Times

Regardless if you’re flying domestically or internationally, online check in is available up to 24 hours before a flight.

You may be able to check in in-person at the airport for a flight several hours before departure, but you may not be allowed through airport security if you are too early.

How Early Can You Check Your Bags for a Flight?

For international flights, and if checking in at the airport, and you want to check bags, you can check in 3-4 hours before the scheduled departure time.

For domestic flights, and if checking in at the airport, and you want to check bags for your flight, you can check in 3 hours before the scheduled departure time.

You Usually Have to Wait to Go Through Airport Security

You can usually go through airport security approximately 3 hours before your flight if you have checked baggage.

This is because airport and baggage counters only open 3-4 hours before a flight, so it’s impossible to go through airport security without first having checked your bag.

While it can vary on the country and on an airport-to-airport basis, if you’re only flying with a carry-on, have checked in online 24 hours before and have your boarding pass, you can go through airport security even earlier.

You Can Likely Enter the Airport At Anytime

Again, while it can vary on an airport-to-airport basis, you can generally enter an airport 24 hours before your flight.

However, some airports don’t have anybody checking at the entrance, so you could technically enter at any time, even if you aren’t flying.

You Probably Don’t Need to Be at the Airport 2 – 3 Hours Early

While it’s recommended that you arrive at an airport 2 or 3 hours before your flight, this is by no means required.

It’s a recommendation to account for long queues and to make absolutely sure that there will be no time issues when checking in, (either with checked bags or without), and going through airport security.

Getting to the airport 2 hours before a domestic flight and 3 hours before an international flight will practically guarantee that there will be minimal stress, and you will make your flight.

How Late Can You Check In For a Flight?

How late you can check in for a flight depends on if you’re flying domestically or internationally, and if you need to check in luggage or not.

Generally, to check in as well as check your bags at the airport, you must do so 45 minutes before the scheduled departure time when flying domestically, and 60 minutes when internationally.

It’s safe to say that it’s definitely better to check in and go through airport security early than checking in at the last moment and worrying about missing your flight.

Ella Dunham, a Freelance Travel Journalist and Marketing Manager, boasts an impressive career spanning eight years in the travel and tourism sectors.

Honored as one of "30 Under 30" by TTG Media (the world’s very first weekly travel trade newspaper), a "Tour Operator Travel Guru" and "Legend Award" winner, Ella is also a Fellow of the Institute of Travel, a Member of the Association of Women Travel Executives, has completed over 250 travel modules, and hosts travel-focused segments on national radio shows where she provides insights on travel regulations and destinations.

Ella has visited over 40 countries (with 10 more planned this year).