United lets you change most flights, but the rules depend on your ticket type and how far ahead you book the change

You can change a United flight through the United website, the United app, or by calling 1-800-864-8331. The change itself is usually free — United does not charge a change fee on most domestic flights. What you may pay is the difference in fare if your new flight costs more than the original one. If your new flight costs less, United keeps the difference as a credit toward future travel on your account, not a refund to your card.

The catch is that some tickets cannot be changed at all. Basic Economy fares — the cheapest option — are locked in and cannot be moved to a different flight. If you bought a Basic Economy ticket, your only option is to cancel and rebook, which means you lose the ticket value unless you use it as a credit later. All other ticket types (Main Cabin, First Class, and premium cabin fares) can be changed.

Key Takeaways

  • Basic Economy tickets cannot be changed to a different flight; you can only cancel and lose the fare value unless you use it as a credit later.
  • Main Cabin and premium tickets can be changed free of charge, but you pay the difference if the new flight costs more.
  • You can change your flight online through united.com, through the United app, or by phone at 1-800-864-8331.
  • If you change within 24 hours of booking, you can change to any available flight on any date; after 24 hours, you can only change to flights on the same day or later.
  • If your flight is cancelled or significantly delayed by United, you can rebook on any available flight at no extra cost, even if it is on a different airline.

How to change your flight online or through the app

Log into your United account on united.com or open the United app. Go to "Manage My Booking" and enter your confirmation number and last name. Select the flight you want to change. United will show you available flights on the same route for the same day and nearby dates. Pick the flight that works for you and confirm the change.

If the new flight costs more, you will see the price difference before you confirm. Pay that difference with the same payment method you used for the original ticket. If the new flight costs less, the savings stay in your United account as a credit and you can use it to book another flight later. The change takes effect when ready, and United sends a new confirmation email with your updated flight details.

Changing your flight by phone

Call United at 1-800-864-8331. Have your confirmation number and last name ready. A representative will pull up your booking, tell you what flights are available, and walk you through the change. If you need to change to a flight on a different day or a different airport, the representative can help with that too — the website and app sometimes show fewer options than a phone agent can access.

Phone changes take longer than online changes (expect to wait 15 to 30 minutes depending on call volume), but they are useful if you need to change to a flight that is not showing up online or if you need help understanding your options. You will still pay any fare difference over the phone, and the new confirmation is sent by email after the call ends.

What happens if you change within 24 hours of booking

If you booked your flight less than 24 hours ago, you have more flexibility. You can change to any available United flight on any date, not just flights on the same day. This applies even to Basic Economy tickets — the 24-hour window overrides the usual restriction on Basic Economy changes.

After 24 hours have passed, the normal rules take over. Basic Economy tickets lock in, and other ticket types can only be changed to flights on the same day or later. If you need to move your flight to an earlier day after the 24-hour window closes, you have to cancel and rebook as a new ticket, which means paying the full new fare.

When United pays for the change instead of you

If United cancels your flight or delays it by more than three hours, you can rebook on any available United flight at no cost, even if it is on a different day or a different airline. You do not pay a change fee, and you do not pay a fare difference — United covers it. This is true regardless of your ticket type, including Basic Economy.

If the new flight you choose costs less than your original ticket, the difference stays as a credit in your account. If it costs more, United absorbs the extra cost. You can also ask for a refund instead of rebooking, though United will refund the original fare price, not the higher price of a replacement flight on another airline.

Changing to a flight on a different day or airport

You can change to a flight on a different day through the website, app, or phone. The website and app let you see available flights for several days out, so you can pick the date that works. If you want to change to a completely different airport (for example, flying into Newark instead of LaGuardia), call 1-800-864-8331 — phone agents have more flexibility to reroute you, and they can explain what the new fare will be before you commit.

Changing to a different airport usually means paying a higher fare, because you are booking a different route. United will show you the price before you confirm. If you are changing because of a schedule conflict or a personal emergency, ask the agent whether you may have access to for any courtesy rebooking — some situations allow agents to waive or reduce the fare difference, though this is not may provide.

What to know about standby flights and waitlists

If the flight you want is fully booked, you can ask to be placed on the standby list. Standby means you are waitlisted for that flight, and if a seat opens up (usually because another passenger cancels), you get it. Standby is free — you do not pay extra to be on the list. You can request standby through the website, app, or by phone.

Standby flights are not may provide, and there is no way to know in advance whether a seat will open. United prioritizes standby passengers by ticket type (premium cabin passengers ahead of Main Cabin, Main Cabin ahead of Basic Economy) and by how long they have been on the list. If you do not get on the standby flight, you keep your original booking and can try again for a later flight or stick with your original reservation.

Frequently Asked Questions

Can I change my flight the day before or the day of departure?

Yes. You can change your flight up until the scheduled departure time. If you change online or through the app, you must do it before the flight departs. If you are at the airport and need to change, go to a United ticket counter and an agent will help you rebook on the next available flight. If the new flight is later the same day, there is no change fee; if it is the next day or later, you pay any fare difference.

What if I want to change to a flight that costs less?

The savings stay in your United account as a credit. You cannot get the money back to your original payment method. You can use the credit to book another flight on United at any time in the future. The credit does not expire as long as you have an active United account, but if you cancel the account, the credit may be forfeited.

Do I lose my seat if I change my flight?

No. When you change to a new flight, United assigns you a new seat on that flight. Your seat assignment depends on your ticket type and frequent flyer status. Premium cabin passengers and frequent flyers get better seat assignments. If you had a paid seat upgrade on your original flight, you may need to repurchase it on the new flight.

Can I change my flight if I booked through a travel website like Expedia or Kayak?

You can change through United directly using your confirmation number, but the change may not show up on the travel website right away. Call the travel website's customer service to confirm the change went through on their end. Some travel websites charge their own change fees on top of any United fare difference, so check their policy before you change.

What if United overbooks my new flight and I do not get a seat?

If you are bumped from an overbooked flight you changed to, United treats it the same as any other overbooking. You are offered compensation (usually a travel credit) and rebooked on the next available flight. The compensation amount depends on how late you arrive at your destination and whether the flight is domestic or international.