The report you file at the airport when your bag does not arrive

Three regimes ask a passenger to put a mishandled bag on the record, and only one of them treats that record as a condition of payment. At a US airport, filing a Mishandled Baggage Report is what unlocks a checked-bag-fee refund. Under the Montreal Convention, what preserves the claim is a written complaint sent to the carrier within 7 or 21 days. This page follows the paperwork from the baggage desk through four regimes and states what filing it, or not, actually changes.

Updated 20 Oct 2026·Sources checked 15 Sep – 20 Oct 2026·8 min read

#What the report you file at the airport is called, and what it records

3 regimes name 3 different documents. US rule 14 CFR 260.5(b) requires a Mishandled Baggage Report. The Civil Aviation Authority’s baggage-complaint list asks for a Property Irregularity Report (PIR). The Montreal Convention requires a written complaint to the carrier and names no report anywhere in article 31.

Source: 14 CFR 260.2, 260.5(b) — ecfr.gov; Civil Aviation Authority, How the CAA can help — caa.co.uk; Montreal Convention 1999 art. 31(2)-(4) — eur-lex.europa.eu, checked 2026-09-15; KLM, Delayed baggage — klm.co.uk; Heathrow Airport, Lost baggage — heathrow.com, checked 2026-10-20.

Nothing in those three sources says the three are one piece of paper. The form at the desk is the carrier’s own document, no regulator here publishes a standard version of it, and none of the three texts says what it has to contain. Article 31 prescribes only that a complaint be in writing and inside its time limit. A damaged wheelchair is reported at the same desk; what it is worth is set out in special assistance when flying.

Airlines and airports name that desk record in their own words. KLM uses the CAA’s term: once you report a missing bag, it issues a Property Irregularity Report (PIR) with a file reference number. Heathrow’s own page calls the record you get at the airline’s desk a missing bag report.

The Canadian Transportation Agency frames the same moment differently again. Its instruction is to contact the airline in writing first, and its claim windows run to the airline, not to the desk. So the useful question is not what the form is. It is whether filing it changed anything, and the answer differs in every regime.

Write down the reference number before you leave the desk, and photograph your copy of the form.

#Where that report is a condition of payment, and where it is only evidence

A Mishandled Baggage Report is a condition in the United States: 14 CFR 260.5(b) refunds a checked-bag fee only when a report was filed after the bag missed its delivery window. No report, no fee refund — the rule states the document as a requirement, not as one way among several to prove the claim.

Source: 14 CFR 260.5(b) — ecfr.gov; Montreal Convention 1999 art. 31(2)-(4) — eur-lex.europa.eu, checked 2026-09-15.

The Montreal Convention runs the opposite way. What conditions the underlying claim, for damage or delay to checked baggage, is a written complaint sent to the carrier within 7 or 21 days under article 31; miss that window and no action lies against the carrier, save in the case of fraud. Article 31 names no report as a requirement anywhere in its text — the form filled in at the desk is evidence supporting the written complaint, not a second gate the claim must also clear.

So the same missing paperwork produces two different failures. On the US bag-fee refund, no Mishandled Baggage Report ends the claim outright; the full 12/15/30-hour table, domestic and international, sits on the airline refund rules page. On a Montreal claim for the bag itself, the airport report was never the thing that had to be filed in time. The written complaint was, and it stays open even without one.

Guard the wrong document and the wrong claim survives it. A passenger who keeps the Property Irregularity Report but never sends the Montreal Convention written complaint has evidence with nothing to attach it to. A passenger who sends the complaint but never filed a Mishandled Baggage Report still has a live Montreal claim for the bag itself, just not the separate US bag-fee refund.

Send the written complaint inside its deadline regardless of whether a report was filed at the airport. Treat the two as separate obligations, not one.

#What the reference number is worth once you claim

6 documents is what the Civil Aviation Authority’s complaints team asks for with a baggage complaint: proof of address, the Property Irregularity Report, itemised lists, receipts, flight details and copies of correspondence with the airline. The report is one of the six. It is evidence of the event, not the document that preserves the claim.

Source: Civil Aviation Authority, How the CAA can help — caa.co.uk; Canadian Transportation Agency, air travel complaints — otc-cta.gc.ca, checked 2026-09-15; KLM, Delayed baggage — klm.co.uk, checked 2026-10-20.

That team, known as PACT, is only likely to take a Montreal baggage complaint once you complained to the airline in writing and were not satisfied, or heard nothing within 8 weeks, and it will not open a case with under a year left to sue. The reference number supports that written complaint. It does not replace the step of sending one, and the full 7/21-day deadline table sits on the lost and delayed baggage guide.

Canada runs the same split. The Canadian Transportation Agency’s own claim windows run to the airline — 7 days for damaged baggage, 21 days for delayed — and a CTA complaint later still needs that written request to the carrier first.

While the bag is still missing, the reference number has a second use: tracking. KLM’s file reference is the key to WorldTracer, the tracking system its delayed-baggage page links to; from 24 hours after the report, your last name and that 10-character reference show the bag’s status. For arrivals at 16 UK airports, Heathrow and Manchester among them, KLM currently takes the report only at the airport baggage desk, not online; the KLM lost luggage guide lists them.

Attach the reference number and a photo of the report to your written complaint. Do not send the report alone and treat it as the claim.

#What to do if you left the airport without filing one

Nothing about the Montreal Convention’s written-complaint deadline moves because no report was filed: 7 days from receipt of a damaged bag, or 21 days from the date a delayed bag is placed at your disposal, still run from the event, and article 31(2) also asks for the complaint forthwith once damage is discovered. Send that complaint in writing regardless.

Source: Montreal Convention 1999 art. 31(2) — eur-lex.europa.eu; Irish Aviation Authority, APR FAQs — iaa.ie, checked 2026-09-15; KLM, General Conditions of Carriage art. 20.1 — klm.co.uk; easyJet, Damaged, delayed or lost luggage — easyjet.com, checked 2026-10-20.

Report the missing bag to the airline anyway, and do it now. That step comes from the airline’s contract, not the Convention. KLM’s conditions of carriage say all missing baggage must be declared as soon as the flight arrives and that later declarations will not be taken into account. easyJet asks you to register a missing bag on its Baggage Portal within 24 hours of the flight arriving.

Of the four regimes on this page, the US bag-fee refund is the one claim a missing report ends outright. 14 CFR 260.5(b) names the Mishandled Baggage Report as the condition, and there is no later substitute for it once you have left with the fee unclaimed. The domestic liability floor is a separate limb again, and it does not depend on this report at all — see the US domestic liability floor.

In Ireland, the Irish Aviation Authority states plainly that no designated body exists for Montreal baggage complaints at all, so a missing report changes nothing about where a claim goes. It was always the carrier, or the courts, not a regulator.

Damage discovered after you leave the airport does not reset any clock either: the 7 days still count from receipt of the bag. Write to the carrier the same day you notice it.

General information, not legal advice. For your specific case, contact Citizens Advice (UK), the US Department of Transportation or the Canadian Transportation Agency.

#Sources

All sources checked 2026-09-15 unless dated otherwise.

• Montreal Convention 1999, arts. 17, 31 — eur-lex.europa.eu
• 14 CFR 260.2, 260.5 — ecfr.gov
• Canadian Transportation Agency, Air travel complaints — otc-cta.gc.ca
• Civil Aviation Authority, How the CAA can help — caa.co.uk
• Irish Aviation Authority, APR FAQs — iaa.ie
• KLM, Delayed baggage — klm.co.uk, checked 2026-10-20
• Heathrow Airport, Lost baggage — heathrow.com, checked 2026-10-20
• KLM, General Conditions of Carriage — klm.co.uk, checked 2026-10-20
• easyJet, Damaged, delayed or lost luggage — easyjet.com, checked 2026-10-20

#FAQ

What is a Mishandled Baggage Report?

14 CFR 260.5(b) is the US rule that names a Mishandled Baggage Report: the document a US bag-fee refund needs after a checked bag misses its delivery window. The Montreal Convention, which governs baggage claims outside US domestic flights, names no such report at all — only a written complaint.

Do I lose my claim if I did not file a report at the airport?

7 days for damage or 21 days for delay: the Montreal Convention’s article 31 written-complaint deadline runs whether or not you filed an airport report. Among the legal regimes, only the US bag-fee refund (14 CFR 260.5(b)) requires one. KLM’s conditions of carriage still say missing baggage must be declared as soon as the flight arrives, so report before leaving.

What does the CAA ask for with a baggage complaint?

6 items make up the CAA’s baggage-complaint document list for PACT: proof of address, the Property Irregularity Report, itemised lists, receipts, flight details and copies of correspondence with the airline. PACT is only likely to take the case once you complained in writing to the airline first.