Whether it’s due to an illness in the family or a work emergency, even the best-laid travel plans can go awry, resulting in you needing to make a last-minute flight change.

The process for late-breaking changes varies by carrier and depends on whether you are attempting to change a refundable or nonrefundable ticket. Once you determine that, you must modify your flight within the allowed time frame for ticket changes set by your carrier.

There are cut-off times for how close to a flight one can change a ticket for a new flight on the major U.S. carriers, which we will spell out in this guide.

You also must consider that carriers have corresponding rules for the absolute latest time you can check in for your flight and still receive a boarding pass, along with requirements regarding how late you can arrive at your gate. They are outlined here.

While this guide details how soon before a flight’s scheduled departure you can change your ticket, the likelihood that you would be able to get on a new flight immediately depends on a few other factors, including seat availability, check-in and gate arrival requirements.

Read on for information about how close to scheduled departure you can change your flight on six major domestic airlines.

In This Post

Alaska Airlines

You can technically buy a ticket for an Alaska Airlines flight up to a few minutes before that flight is set to depart. However, you must still adhere to the airline’s check-in policies, which require travelers to check in for their flight at least 40 minutes before scheduled departure, regardless of whether they are checking a bag.

Therefore, it would only be possible to change an Alaska flight and book a new flight that same day if you could meet the 40-minute check-in cut-off timeframe.

Also, note that Alaska travelers can make same-day confirmed changes during the aforementioned check-in window (up to 24 hours ahead of flight) for a $25-50 fee instead of paying a fare difference, for main cabin and first-class fares.

American Airlines

American Airlines doesn’t technically have a policy for this, but you should change your flight at least two hours before departure, regardless of whether you’re attempting to change your reservation via phone or online.

“But if you’re at the airport and it’s a very simple change, such as deciding to take an earlier or later flight, they can help until the flight is closed,” said an AA spokesperson. By this they mean when check-in for the flight is closed, not the gate closing and the aircraft door shutting.

Delta

Offering flexibility for travelers, Delta allows those with award booking to make changes to award tickets any time before departure. For non-award tickets, Delta flyers can make same-day changes within 24 hours of their originally scheduled flight, online during check-in or within the Fly Delta app.

If your originally booked seat is available on the new flight, you can change your ticket to a confirmed seat on a new flight, starting at $75, depending on the ticket type. Delta Medallion Diamond, Platinum and Gold Members are not charged this fee.

If you cannot find a seat available in your originally purchased fare class, you can stand by for a seat on an earlier flight than your original ticket. Note that nonrefundable fare types, such as basic economy, are not eligible for same-day changes, but can be canceled for a partial flight credit.

JetBlue

Per JetBlue policy, passengers can request a flight change anytime before scheduled departure. If customers do so on the same calendar day as their original flight, they can pay a flat fee of $75 to switch flights without paying a fare difference. This fee is waived for TrueBlue Mosaic members.

“A same-day switch can only be made on the day of travel, beginning at midnight in the time zone of your departing flight,” JetBlue says online, noting this is only an option for travelers at airports offering multiple flights per day.

Southwest

Keeping in line with its generous baggage policy, which affords all passengers two free checked bags, regardless of fare type, Southwest also has one of the most customer-friendly flight change and cancellation policies. SWA travelers can voluntarily change or cancel their flight up to 10 minutes ahead of departure, regardless of booking type.

While the Dallas-based airline does not charge change fees to change any fare type, a fare difference may apply for both cash and Southwest Rapid Rewards point bookings. If a traveler cancels a flight booked with Rapid Rewards points, those points will be added back to your account. If you cancel a flight booked with cash, you’ll receive a flight credit, which is valid for travel at any time since they no longer expire as of July.

United

United customers can make changes to their flight before or after they check in, all the way up to their flight’s scheduled time of departure, applicable to both revenue and award tickets. Note the check-in period for United flights ends 60 minutes before scheduled departure.

However, if you want to change your ticket for free, your new flight must depart within 24 hours of your original scheduled departure, earlier or later, pending seat availability.

Those who had planned to check a bag need to confirm their intention of modifying their flight at least one hour before their new flight’s departure so United’s baggage team can “do their best to move the bags to the new flight,” according to a United spokesperson.

If a member’s original ticketed fare class isn’t available on the new flight, expect to pay a fare difference if applicable or consider flying standby, which is available to all United flyers free of charge.

Bottom line

Just because you can technically change your flight within the abovementioned parameters doesn’t mean you should.

“I wouldn’t chance changing your flight [when there’s] less than one hour until boarding,” said TPG senior aviation reporter David Slotnick, citing seat availability, check-in policies and the logistics of rerouting checked baggage if necessary.

Review the same-day change policies as specified by your carrier to determine the absolute latest time you can modify your flight, should unforeseen circumstances require you to do so.

For more details on how to change tickets on specific carriers, read on:

How to change or cancel a Delta Air Lines flight
How to change or cancel a Southwest Airlines flight
How to change or cancel a JetBlue flight
How to change or cancel an American Airlines flight
How to change or cancel a United Airlines flight