What is online check-in and how does it work?

Online check-in is the process of confirming your flight reservation via an airline's website or app before arriving at the airport. Passengers enter a booking reference, verify their itinerary, select or adjust seats, add baggage, and receive a digital or printable boarding pass. Most travelers complete the process in a few minutes.

When does the online check-in window open?

Online check-in typically opens 24 hours before the scheduled departure time for most domestic and short-haul international routes. Long-haul carriers often extend the window to 48 hours, and some premium programs allow check-in 72 hours ahead. For early-morning flights, the window usually opens the evening before departure.

Can I check in online for an international flight?

Yes, in most cases. Online check-in is available for the majority of international routes, though some flights require in-person document verification at the counter, particularly for routes with stricter visa or immigration controls. The airline's website will indicate whether online check-in is available when you enter your booking reference.

What happens if I miss the online check-in window?

Missing the online check-in window doesn't prevent travel. You'll check in at the airport counter or kiosk instead. The main consequence is seat selection: by the time the counter opens, preferred seats are often taken by passengers who checked in online. Arriving at the airport with extra time is advisable.

How does online check-in work for corporate travel bookings?

The booking reference that initiates online check-in comes from the original flight reservation. When bookings are made through a corporate travel platform like Navan, that reference is stored in the traveler's trip view and accessible when the check-in window opens. Some corporate policies also specify what passengers can change during check-in, such as seat category or upgrade acceptance.

Is a mobile boarding pass accepted everywhere?

Mobile boarding passes are accepted at security and boarding gates at most major airports worldwide. They display via the phone's native wallet app without requiring a cell signal, which is useful during international travel. A small number of airports in certain regions may still require printed passes, so verifying local requirements before a first visit to an unfamiliar airport is worthwhile.

How does completed online check-in relate to duty of care tracking?

A confirmed online check-in indicates the traveler is actively proceeding with a booked flight, providing useful context for travel managers during disruptions. Corporate travel platforms like Navan track booked itineraries, and actual check-in confirmation is a separate signal that security teams may use when coordinating responses to cancellations or emergencies.

What is Online Check-In? How It Works

Online Check-In

The process by which a passenger confirms their reservation on a flight through an airline's website or mobile app, typically beginning 24 to 48 hours before departure. Completing online check-in generates a digital or printable boarding pass and allows travelers to select seats, add checked baggage, and verify travel documents before reaching the airport.

Victoria Landsmann

•June 11, 2026•

6 minute read

Key Takeaways

Online check-in is the digital process of confirming your place on a booked flight via an airline's website or app. The check-in window typically opens 24 to 48 hours before departure, generating a digital or printable boarding pass without the need to queue at an airport counter.

Airlines typically open online check-in between 24 and 48 hours before departure, though some long-haul carriers extend the window to 72 hours for certain routes.
Passengers can select or change seats, pre-pay for checked baggage, enter passport details for international flights, and download a digital boarding pass during check-in.
The IATA 2025 Global Passenger Survey found that 78% of travelers want a single smartphone interface combining their digital wallet, passport, and loyalty cards for airport processes [1].
Corporate travel platforms like Navan centralize booking confirmation details, making it easy to retrieve the reference number travelers need when the check-in window opens.
Biometric check-in is growing: 50% of passengers used biometrics at airports in 2025, up from 46% the year before [1].

What is Online Check-In?

Online check-in is the process of confirming your reservation on a flight via an airline's website or mobile app before arriving at the airport. It typically opens between 24 and 48 hours before the scheduled departure time, though the exact window varies by carrier and route.

When passengers complete online check-in, they receive a boarding pass, digital or printable, that grants entry to the security area and the boarding gate. The process replaces the traditional airport counter check-in for most travelers, reducing time spent at the airport before a flight.

How Online Check-In Works

Online check-in follows a consistent sequence across most carriers:

Start the process. Open the airline's website or mobile app and navigate to the check-in section, usually accessible from your upcoming trips or booking confirmation.
Enter your credentials. Provide your booking reference and last name, or log in to your frequent flyer account if it's linked to the reservation.
Verify your details. Confirm your flight information and, for international travel, enter or verify passport details.
Select your seat. Most airlines display the full seat map during check-in, allowing changes to the initial assignment. Some offer paid or points-based upgrades at this step.
Declare or add checked baggage. Pre-paying for baggage at check-in is typically cheaper than paying at the counter on departure day.
Receive your boarding pass. Download the digital version to your phone's wallet app or email, or print a copy if preferred.

Most travelers complete the process in a few minutes.

When Does Online Check-In Open?

The check-in window varies by carrier but follows a pattern most business travelers can plan around:

24 hours before departure is the most common opening time, particularly for domestic flights in the U.S. and Europe.
48 hours before departure is offered by several long-haul and international carriers.
72 hours or more is occasionally available for premium cabin passengers or loyalty program members.

For early-morning flights, the 24-hour mark falls the previous evening, worth noting when managing a dinner meeting or hotel arrival before an early departure. Checking in promptly when the window opens typically yields better seat selection on full flights.

What You Can Do during Online Check-In

Online check-in has expanded beyond simple reservation confirmation. Passengers can now:

Change or select seats: Airlines release the full seat map at check-in. Early access often means the best available economy seats are still open.
Add and pre-pay for checked bags: Counter fees for bags added at the airport are typically higher than the rate available during online check-in.
Enter travel document details: International flights may prompt for passport number, expiration date, and country of issuance. Some carriers run a preliminary document verification at this stage.
Access upgrade offers: Paid or points-based upgrades are often presented at check-in for available premium seats. Corporate travel policies vary on whether travelers may accept these without prior approval.

Online Check-In and Business Travel Policy

For business travelers, online check-in decisions can affect the expense report. Seat upgrades, extra baggage fees, and seat selection charges added during check-in all require documentation and may fall outside travel policy compliance guidelines.

Some travel programs address the check-in stage directly: specifying which seat categories employees may select, whether upgrades require pre-approval, and whether passport details should be stored in a central traveler profile rather than re-entered flight by flight. Centralizing passport data reduces repetitive entry and errors for frequent travelers.

When bookings flow through a corporate platform like Navan, travelers see all flight details in a single trip view, making it straightforward to retrieve the booking reference when check-in opens. This creates a central record connecting the travel management company and finance team to the traveler's actual itinerary.

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How Biometrics Are Reshaping the Check-In Process

Online check-in is converging with biometric identification in a way that is gradually making the boarding pass optional at some airports. The IATA 2025 Global Passenger Survey found that 74% of passengers would share biometric data to skip presenting a passport or boarding pass at security, immigration, and boarding checkpoints [1]. As of 2025, 50% of passengers had used biometrics at some point during their airport journey, up from 46% in 2024 [1].

In practice, some airports now let passengers who have pre-registered their biometrics bypass both the counter visit and the boarding pass step, using facial recognition at security and boarding gates. Electronic bag tags, which passengers generate directly from a mobile device during check-in, rose from 28% adoption in 2024 to 35% in 2025 [1].

For corporate travelers, this trend means the booking and traveler profile are increasingly the check-in anchor, not the 24-hour login window. The confirmation of travel happens earlier in the process, and airport passage grows progressively more automated.

When Online Check-In Isn't Available

Not every traveler or flight is eligible for online check-in. Common situations requiring in-person counter check-in include:

Document verification requirements: International routes where an airline cannot verify visa or immigration documents electronically require in-person check-in to inspect physical documentation.
Special assistance needs: Passengers requiring wheelchair services, traveling with pets in the cabin, or using certain medical equipment typically check in at the counter to confirm arrangements.
Group bookings: Flights booked for larger groups sometimes require counter check-in to coordinate seat assignments across the full party.
Codeshare flights: On certain codeshare routes where the operating carrier and the ticketing carrier differ, one airline's online check-in system may not recognize bookings made through the other. Contacting the operating carrier directly resolves this in most cases.
First-entry document checks: Some carriers require manual document verification on the first flight between specific country pairs, then allow online check-in on subsequent trips once documents are on file.

When online check-in is unavailable, arriving at the airport with additional time for counter processing is important, particularly at busy hubs during peak travel periods.

Tips for Business Travelers

Business trips often involve early departures, tight connections, and back-to-back travel days. Online check-in makes each more manageable when approached intentionally.

Set a calendar reminder for when check-in opens. For fully booked flights, missing the 24-hour window often means middle-seat assignments. A brief calendar event keeps the check-in window on your radar without requiring active monitoring.

Review your company's upgrade policy before the check-in screen appears. Upgrade prompts appear at check-in on many airlines. Knowing your travel policy in advance turns a potentially awkward expense conversation into a quick, informed decision.

Save your boarding pass to your phone's wallet app rather than only your email. Digital boarding passes display without a cell signal, which matters during international travel when roaming is off.

Keep your booking reference accessible. If online check-in requires the booking reference rather than your frequent flyer number, retrieve it from the original confirmation. Most business travel itinerary tools store this automatically. For a structured pre-departure approach, a business travel checklist can help ensure nothing is missed before heading to the airport.

For multi-leg international trips, confirm that the electronic ticket covers all segments before starting check-in. Some multi-airline journeys require separate check-in for each leg, each with its own opening window.

Knowing whether employees have checked in also matters for duty of care oversight: a confirmed check-in indicates the traveler is actively proceeding with the booked flight, providing travel managers useful context during disruptions.

Sources

[1] International Air Transport Association (IATA), "IATA's 2025 Global Passenger Survey Reveals Mobile and Digital ID as the Future of Travel," November 5, 2025. https://www.iata.org/en/pressroom/2025-releases/2025-11-05-02/

Frequently Asked Questions About Online Check-In

Online check-in is the process of confirming your flight reservation via an airline's website or app before arriving at the airport. Passengers enter a booking reference, verify their itinerary, select or adjust seats, add baggage, and receive a digital or printable boarding pass. Most travelers complete the process in a few minutes.
Online check-in typically opens 24 hours before the scheduled departure time for most domestic and short-haul international routes. Long-haul carriers often extend the window to 48 hours, and some premium programs allow check-in 72 hours ahead. For early-morning flights, the window usually opens the evening before departure.
Yes, in most cases. Online check-in is available for the majority of international routes, though some flights require in-person document verification at the counter, particularly for routes with stricter visa or immigration controls. The airline's website will indicate whether online check-in is available when you enter your booking reference.
Missing the online check-in window doesn't prevent travel. You'll check in at the airport counter or kiosk instead. The main consequence is seat selection: by the time the counter opens, preferred seats are often taken by passengers who checked in online. Arriving at the airport with extra time is advisable.
The booking reference that initiates online check-in comes from the original flight reservation. When bookings are made through a corporate travel platform like Navan, that reference is stored in the traveler's trip view and accessible when the check-in window opens. Some corporate policies also specify what passengers can change during check-in, such as seat category or upgrade acceptance.
Mobile boarding passes are accepted at security and boarding gates at most major airports worldwide. They display via the phone's native wallet app without requiring a cell signal, which is useful during international travel. A small number of airports in certain regions may still require printed passes, so verifying local requirements before a first visit to an unfamiliar airport is worthwhile.
A confirmed online check-in indicates the traveler is actively proceeding with a booked flight, providing useful context for travel managers during disruptions. Corporate travel platforms like Navan track booked itineraries, and actual check-in confirmation is a separate signal that security teams may use when coordinating responses to cancellations or emergencies.