How to Use an Airline Travel Credit to Book a New Flight

By the SlickFlight travel desk · Published November 2, 2026 · Facts checked November 2, 2026

You use an airline travel credit the same way on all four big US airlines: search for the new flight on the airline's website or app, and choose the credit as the payment method at checkout. The credit's confirmation or ticket number connects it to the new booking, and you pay any difference with a card.

The mechanics are easy. The rules around them are where credits quietly go to waste: dates that mean "travel by" rather than "book by", credits locked to one traveler's name, and expiry dates that carry over from one booking to the next.

The short version

All of this comes from each airline's own pages, checked in November 2026.

United

United has two kinds of credit. A future flight credit comes from cancelling a trip or changing to a cheaper flight. A travel certificate comes from giving up your seat or as a goodwill gesture.

To use either one, shop for your flight as normal. At checkout, choose "Travel Credits" as the payment option; credits linked to your MileagePlus account appear automatically, and you tick the one you want. If a credit isn't listed, or you don't have an account, look it up from the checkout page with the confirmation number (future flight credits) or PIN (certificates).

You can combine several credits of the same type in one purchase, but United doesn't let you mix future flight credits with travel certificates.

Here's the trap. On a future flight credit, the expiry date is a travel-by date: your trip has to begin before it. On a travel certificate it's a book-by date. People see a date three weeks away, book a flight for next spring and are surprised when the credit won't apply.

Two more United rules worth knowing. A future flight credit normally has to be used by the traveler it was issued to (credits from tickets bought on or before August 31, 2021 are the exception). And you can put credits toward some extras, like Economy Plus seating, but only while buying the ticket, not afterwards.

Delta

Delta calls them eCredits. If your SkyMiles account was on the original booking, the eCredit sits in your profile. If not, go to delta.com/redeem, look up the eCredit by its number from your flight receipt email, or by the last name and phone number on it, then enter the original ticket holder's first and last name.

Select the eCredit, continue to the flight search, and pick your flights. The trip total shows how much the eCredit covers; if the new flight costs more, you pay the difference on the Review and Pay page.

Delta says an eCredit from cancelling a non-refundable ticket expires one year from the purchase date of the original ticket, unless your ticket terms say otherwise. That's the trap: the clock started when you bought the first ticket, not when you cancelled it. Cancel in October a ticket you bought in January and you have about three months left.

Credits Delta issues after it significantly changes or delays your flight can last longer: Delta says those eCredits are valid for five years from issue.

American

American's steps are short. Find your travel credit, or log in to your AAdvantage account and open "Travel credit" from the account summary. Copy the Trip Credit or Flight Credit ticket number, search for your new flight on aa.com or the app, and choose the credit type on the payment screen.

Keep the cancellation email. American says it holds the ticket number and original confirmation code you need to rebook, which matters if you aren't an AAdvantage member.

The trap with American is extras. Travel credit can't be used for seats, upgrades or bags, so a credit that exactly matches a fare still leaves you paying for anything else by card. And if you paid for bags or seats at the airport on the trip you cancelled, American says those fees are non-refundable.

Southwest

Southwest applies flight credits on the payment screen: choose to apply a flight credit and enter the confirmation number it came from. Each passenger can use up to three forms of payment per booking, and each credit counts as one. If you got two credits from the same confirmation number, for example one for the fare and one for a purchased seat, enter them separately.

How long it lasts depends on when and how you booked. Credits created on or before May 27, 2025 don't expire. For reservations booked or changed from May 28, 2025:

• Choice, Choice Preferred and Choice Extra fares paid by card become a Transferable Flight Credit that expires 12 months from the original booking date.
• Basic fares paid by card become a flight credit that expires 6 months from the original booking date.
• All travel must be completed by the expiry date, not just booked.

Here's the trap that catches people who rebook more than once. If you pay for a new Southwest booking with a flight credit and later cancel it, the new credit takes the earliest expiry date of the credits you used. Rolling a credit forward doesn't reset the clock.

If Southwest significantly disrupts your flight and you take a credit instead of a refund, that credit is valid for five years. And Transferable Flight Credits from Choice fares can be transferred once to another Rapid Rewards member.

Before you book with a credit

• Check the expiry date and whether it means "book by" or "travel by". United and Southwest are travel-by for flight credits.
• Check whose name is on the credit. Booking someone else usually needs a transferable credit or a card.
• If an agency sold the original ticket, the credit usually goes back through that agency. United states this outright.
• Price the new trip both ways. A credit is money you've already spent with that airline, but a cheaper fare on another airline can still beat it if the credit will expire unused anyway.

A credit only works with the airline that issued it. If the new trip is better on a different airline, SlickFlight can price that fare for you; the credit itself stays with the original airline.

Common questions