Reservations & ticketing Travel technology glossary

Schedule changeAirline-initiated flight change

Also called SKCHGsked changeinvoluntary schedule changetime changeTK status

Definition

A schedule change is a change an airline makes to a booked flight before departure, such as a new departure time, flight number, routing or a cancellation. The airline updates the booking, the agency receives a notice, and the agent must review it with the traveller, accept or rebook, and reissue or refund the ticket under the airline's policy.

What Schedule change means

Airlines adjust their timetables constantly, and those changes land in bookings already made. In a GDS, the affected segments show special status codes and the PNR is placed on the agency's schedule change queue. Travelport, for example, uses TK for a schedule change and TL for a schedule change on a waitlisted segment, both meaning the passenger must be told the new times.

Airlines separate planned schedule changes from short-notice disruption. American Airlines treats changes made more than 72 hours before departure as schedule changes. Lufthansa Group uses SKCHG for planned changes made earlier than one calendar day before the first affected flight, and INVOL for day-of or day-before irregularities.

Each airline sets its own rules for what counts as significant, which alternative flights agents may book without extra charge, and when a refund is allowed. Accepting a change usually means reissuing or revalidating the ticket with a special endorsement, which is an involuntary reissue.

Regulation adds minimum rights. Under the US Department of Transportation's automatic refund rule, in force since 28 October 2024, a significant change includes departing more than 3 hours earlier or arriving more than 3 hours later on a domestic flight, or more than 6 hours on an international flight, plus airport changes, extra connections and downgrades. Ticket agents that are the merchant of record must refund once the airline confirms a refund is due. In the EU, Regulation 261/2004 gives passengers on cancelled flights the choice of a refund or re-routing.

How Schedule change works

Schedule changes follow a set path from the airline's timetable update to an updated ticket.

  1. Airline updates the flightThe airline changes its schedule and sends the new details to the booking, marking affected segments with schedule change statuses such as TK or UN.
  2. Booking reaches the queueThe GDS or NDC channel places the PNR on the agency's schedule change queue for review.
  3. Check impactThe agent checks new times, connections against minimum connecting time, and other airlines' segments that may now misconnect.
  4. Contact the travellerThe agent explains the change and the options the airline's policy allows, such as accepting, moving to another flight or a refund.
  5. Update the bookingThe agent accepts the change or rebooks, clears old segments and status codes, and moves seats and SSRs to new flights.
  6. Fix the ticketThe ticket is revalidated, reissued with the airline's schedule change endorsement, or refunded, before the airline's deadline.

Schedule change in practice

Verified airline policy details:

  • American Airlines: changes of 61 minutes or more widen rebooking options; refunds apply for overall changes of 181 minutes or more on domestic trips and 241 minutes or more internationally. Reissues must start the endorsement box with SKCHG, and unprocessed changes three days before departure can lead to a debit memo.
  • Qantas: notifies agents with a UN/TK change and auto-revalidates where possible; reissues show QFSKEDCHG in the endorsement box with no fee or additional collection.
  • Lufthansa Group (2023 policy): one free involuntary rebooking; an involuntary refund applies if times move two hours or more, or departure moves more than 60 minutes earlier.

Who uses it

Travel agenciesAgents work schedule change queues daily, contact affected travellers and reissue or refund tickets before airline deadlines.
TMCsCorporate travel teams reprotect travellers and use automated tools to process high volumes of schedule changes.
AirlinesAirlines publish schedule change policies that define permitted alternatives, endorsements and refund thresholds for agency tickets.
Booking platformsOnline systems ingest airline change notifications, alert customers and offer self-service accept, rebook or refund options.

Advantages and limitations

Advantages

  • Gives travellers advance notice and options instead of discovering changes at the airport.
  • Airline policies usually allow free rebooking within set limits, protecting the traveller's trip.
  • Regulations such as the US DOT rule set clear refund rights for significant changes.
  • Standard status codes and queues let agencies handle changes systematically.

Limitations

  • Every airline defines significant changes, permitted alternatives and endorsements differently.
  • Unworked queues can leave travellers with invalid tickets or broken connections.
  • Changes on one airline can break connections to another airline on a separate ticket.
  • Mistakes in schedule change reissues are a common source of debit memos.

Frequently asked questions about Schedule change

What does TK status mean in a booking?

TK is the status a GDS shows on a segment the airline has changed, meaning the passenger must be advised of the new schedule. In Travelport, TL is the equivalent on a waitlisted segment. The agent should review the change with the traveller and then accept it, which converts the segment to confirmed, or rebook under the airline's policy.

Is a passenger entitled to a refund after a schedule change?

Often, if the change is significant. Each airline sets thresholds in its policy, and some laws add minimum rights. For flights covered by the US DOT rule, a departure more than 3 hours earlier or an arrival more than 3 hours later domestically, or 6 hours internationally, qualifies if the passenger does not accept the alternative.

Who has to refund the ticket after a schedule change, the airline or the agency?

It depends on who sold the ticket and on local rules. Under the US DOT refund rule, a ticket agent that is the merchant of record must issue the refund within 7 business days for card payments, or 20 calendar days otherwise, once the airline confirms the passenger qualifies. In BSP markets, agents normally process refunds through BSPlink under the airline's policy.

Does EU261 apply to schedule changes?

EU Regulation 261/2004 deals with cancellations, long delays and denied boarding rather than retimings as such. For cancellations it gives passengers the choice of a refund or re-routing, and compensation may be due if they are told less than two weeks before departure, unless extraordinary circumstances apply. Whether a large retiming counts as a cancellation depends on the case.

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Sources and further reading

  1. US Department of Transportation — Small business compliance guide: refunds final rule (2024)
  2. US Department of Transportation — What airline passengers need to know about DOT's automatic refund rule
  3. American Airlines SalesLink — Schedule change
  4. Qantas AgencyConnect — Qantas schedule change policy
  5. Lufthansa Group — Schedule change and irregularity policy for travel agents (2023)
  6. Travelport — PNR status codes
  7. legislation.gov.uk — Regulation (EC) No 261/2004, Article 5
  8. European Union — Your Europe: air passenger rights