Airline changed your flight: when it counts as a "significant" schedule change

The seven triggers

The federal refund rules define a "significantly delayed or changed flight" as a change or delay made by the airline where, as a result, one of these is true. The definition applies to US and foreign airlines on scheduled flights to, from or within the United States. 14 CFR 260.2

Source: 14 CFR 260.2, eCFR (title 14 current as of Oct 29, 2026), read Oct 31, 2026. The rule doesn't separately define "domestic" and "international" itineraries.

When the two disability triggers apply, anyone on the same reservation who doesn't want to travel without that passenger is owed a refund too. 260.6(b)

How the hours are counted

• From the times you bought. DOT's explanation of the rule: the timeframes "are measured from the original departure and arrival times offered to consumers when they purchased their tickets".
• Accepting a change doesn't reset the clock. DOT rejected airline requests to restart the count each time a passenger accepts a change, calling a reset "fundamentally unfair". Its example: a domestic flight first projected 2 hours late that slips 2 hours at a time to 8 hours late would never qualify if the clock reset.
• First departure, final arrival. The test covers leaving earlier on the first flight and arriving later at your final destination. A late departure on its own isn't a trigger if you still arrive within the limit; DOT reasoned that you're already at the airport and the late start alone doesn't add much travel time.
• "Three hours or more" includes exactly three. A change from 9:00 to 12:00 on a domestic trip qualifies; 2 hours 59 minutes doesn't.

Source: DOT, Refunds and Other Consumer Protections, final rule, 89 FR 32760 (Apr. 26, 2024), section on the definition of "significant change of flight itinerary", read on govinfo.gov Oct 31, 2026. The refund requirements took effect for airlines on Oct 28, 2024.

Worked examples

These apply the rule's text to made-up itineraries. They aren't real flights.

Changes that don't count

• Below the lines. A 2-hour domestic shift or a 5-hour international shift doesn't meet the federal test (though your airline may be more generous, see below).
• A different plane, same cabin. DOT dropped a proposal to count aircraft swaps that downgrade the onboard experience, except for missing accessibility features. If a swap means you lose something you paid for, like a seat type or Wi-Fi, that fee has to be refunded under a separate rule. 14 CFR 260.4 (more in refund refused or stuck as a credit)
• Only the flight number changed. DOT isn't enforcing the refund rule for flights that are only renumbered, if you're rebooked on the new number and it runs without a significant change. The pause runs until July 7, 2027. 91 FR 41556
• A diversion after takeoff. DOT said it doesn't view the refund requirement as applying when a flight that already departed is diverted for safety or security reasons and passengers still get to their destination. 89 FR 32760, preamble

Airline policies vs the federal floor

DOT said airlines with shorter timeframes "are not only permitted under this final rule to continue these polices but are encouraged to do so". What it doesn't allow is a contract term that is inconsistent with the federal refund rules. 14 CFR 260.11 Here's what four large US airlines' own documents said when we read them tonight:

American's page and United's contract were read with a headless browser because plain requests were blocked or timed out. We didn't check other airlines tonight. Where an airline's wording is vaguer or stricter than 14 CFR 260.2 (United's "as determined by UA", or American's "more than 4 hours to your departure time"), the federal definition is still the minimum for covered flights.

What the airline must tell you

• That the flight changed. After a cancellation or significant change, the airline must "timely notify affected consumers" about it and about any alternative it offers instead of a refund. 14 CFR 260.9(a)
• That you can get a refund, when you're owed one, through its notification system and the channels you signed up for (email, text, app push). 260.9(b)
• Close to departure: within 30 minutes of learning about a cancellation, diversion or delay of 30+ minutes in the 7 days before the flight, the airline must update passengers, its website and airport displays. 14 CFR 259.8
• Any credit offer must state your refund right and the credit's terms, and a credit offered instead of a refund must last at least 5 years. 260.6(c)

What to do, step by step

1. Compare against the original. Find your first confirmation email or receipt and write down the original departure, arrival, airports, number of stops and cabin. Screenshot the change notice.
2. Measure. Earliest new departure vs original departure, and final arrival vs original final arrival. Use 3 hours (domestic) or 6 hours (international), or your airline's shorter figure if it has one.
3. Decide. Keep the new flight, ask for a different one, or decline and ask for a refund. Accepting a travel credit counts as your alternative to cash, so don't tap "accept credit" unless that's what you want. 14 CFR 260.7
4. Say no in writing. For example: "My flight [number, date] was changed from [original times] to [new times], a change of [hours]. I don't accept the change, rebooking or a credit. Please refund the fare, taxes and fees to my original payment under 14 CFR 260.6."
5. If you don't answer, the refund becomes automatic once the changed flight departs without you, or by the original departure date if you were only offered a credit. 260.6(a)(2)(iii)
6. Count the deadline: 7 business days on a credit card, 20 calendar days otherwise.
7. Still nothing? Write to the airline, then file a DOT complaint with your before-and-after screenshots.

Booked through a travel site? The refund duty sits with the company that charged your card. See booked through a travel site. If the change happened on the day of travel, the cancelled or delayed flight guide covers meals, hotels and the tarmac rules.

Foreign airlines and trips abroad

The definition covers foreign airlines on scheduled flights to, from or within the United States, including itineraries with a brief foreign stopover. 260.2 ("covered flight") A flight wholly outside the US falls under local rules. United's contract says that for flights starting outside the US, local or international laws on schedule changes apply instead of its Rule 24 where they exist. We didn't read the EU's or other countries' rules tonight, so this page doesn't quote them.

Sources

• 14 CFR part 260 (definitions in 260.2; 260.4, 260.6, 260.7, 260.9, 260.10, 260.11): eCFR (title 14 current as of Oct 29, 2026; read Oct 31, 2026).
• 14 CFR 259.8, notifying passengers of delays and cancellations: eCFR (read Oct 31, 2026).
• DOT, Refunds and Other Consumer Protections, final rule, 89 FR 32760 (Apr. 26, 2024), preamble discussion of the "significant change" definition: govinfo.gov (read Oct 31, 2026).
• DOT, notification of enforcement discretion for renumbered flights, 91 FR 41556 (July 7, 2026): govinfo.gov. A Federal Register search on Oct 31, 2026 found no newer rule amending part 260.
• Delta Contract of Carriage, Rule 19 (delta.com) and Schedule Changes page (delta.com), read Oct 31, 2026.
• American Airlines Conditions of Carriage, updated Aug 13, 2026: aa.com. Plain requests returned HTTP 403 on Oct 31, 2026; read the same day in a headless browser.
• United Contract of Carriage, revised Sep 30, 2026, Rule 24: united.com. Plain requests timed out; read Oct 31, 2026 in a headless browser.
• Southwest Contract of Carriage, 58th revision, effective Sep 24, 2026: southwest.com (PDF) (read Oct 31, 2026).
• DOT's own consumer pages on transportation.gov returned HTTP 403 to our reader on Oct 31, 2026, so this page relies on the regulation and the Federal Register text instead.