If your checked bag is missing, report it before you leave the airport and get a Property Irregularity Report (PIR). Keep the reference number. A PIR starts the airline's baggage trace, but it isn't necessarily the formal claim for reimbursement.

The often-cited 21-day rule isn't a universal deadline for filing a lost-baggage claim. For qualifying international carriage under the Montreal Convention, an undelivered bag can generally be treated as lost after 21 days. Damage and delay have different written-complaint deadlines. Covered U.S. domestic carriage has no federal day-21 loss rule.

These rules concern checked baggage accepted into the airline's custody. A bag left in a terminal, stolen from a rental car, or lost as unchecked hand luggage may involve different rules and proof requirements.

The baggage deadlines that matter

The 30-day statement applies to covered U.S. domestic claims under Part 254. A carrier may allow more time, and its contract should explain when the clock starts and what documents it requires.

An airport report and a compensation claim are not always the same thing. Don't assume that a PIR alone completes the airline's formal written claim. Send the claim through the carrier's designated portal or by email, and save proof of submission.

Which rules control the claim?

Covered U.S. domestic flights

For covered domestic transportation, 14 CFR Part 254 is the federal starting point. The rule applies to the domestic carriage covered by its terms, including service involving large aircraft.

Part 254 requires a covered carrier to set a baggage liability limit of at least $4,700 per passenger under the current figure. That amount is not an automatic payment. You still need to show that the airline had the bag, what was lost or damaged, and the value of the loss. The carrier's contract may also address excluded property, documentation, and the valuation of used items.

Part 254 also prevents a covered carrier from imposing a baggage-claim filing period shorter than 30 days. It does not say that every missing bag becomes legally lost on day 21. Airlines use their own tracing and declaration procedures, so ask when the carrier will accept a lost-baggage valuation claim rather than waiting for an international deadline that may not apply.

Qualifying international carriage

The Montreal Convention generally governs baggage loss, damage, and delay when an itinerary qualifies as international carriage between countries covered by the treaty. The exact itinerary matters, so don't assume that a flight is covered merely because it was booked through an international website. The European Consumer Centre's baggage guidance also describes the 21-day loss rule and the two-year period for court action.

The Convention provides these separate deadlines:

• If the bag hasn't arrived after 21 days, you can generally treat it as lost for purposes of enforcing your rights.
• A damage complaint must be made in writing no later than 7 days after the bag is received.
• A delay complaint must be made in writing no later than 21 days after the bag is placed at your disposal.
• An action against the airline must generally be brought within 2 years. Depending on the circumstances, that period is counted from the aircraft's arrival, its scheduled arrival, or the date the carriage stopped.

The two-year period is a litigation deadline. It doesn't mean the airline's claim portal will stay open for two years, and it doesn't excuse a missed 7-day or 21-day written-complaint period.

The current Montreal baggage liability limit is 1,519 Special Drawing Rights (SDR) per passenger. This figure took effect on December 28, 2024. Its value changes with the SDR exchange rate, but it is roughly around $2,000 or EUR 1,900. The Air France liability notice illustrates how airlines describe this SDR-based limit.

EU261 and baggage

EU261 is not usually the source of compensation for a lost, damaged, or delayed bag. It mainly covers denied boarding, cancellations, and certain flight delays. Baggage claims are generally handled under the Montreal Convention or another applicable national or contractual rule.

A trip involving the European Union or the United Kingdom can still require an itinerary-specific analysis. A flight entirely within another country may be governed by that country's baggage rules instead.

Connecting flights

Report the missing bag at the airport where you were supposed to receive it, usually the final destination shown on the ticket. If there is no baggage desk, contact the airline immediately through its app, website, or telephone channel and keep the confirmation.

The ticket, operating carrier, and countries included in the itinerary can affect both the applicable law and which airline handles the claim. Ask the carrier to confirm the claim reference and the correct department. Sending duplicate claims to several airlines can make the file harder to track.

How much can you claim?

There is usually no flat payment just for the inconvenience of losing a bag. The claim normally concerns documented financial loss and reasonable expenses, subject to the applicable liability limit and the carrier's terms.

The limit is a ceiling on the airline's liability, not a guaranteed amount. If the documented loss is lower, the airline generally won't pay the full limit. If the loss is higher, the applicable cap may control.

Airlines may value used clothing, luggage, and electronics according to their age and condition rather than paying for brand-new replacements. Receipts are useful, but they aren't the only evidence. Photos, order histories, bank or card statements, warranties, and a clear inventory can help establish ownership and value.

Carrier terms may restrict or exclude categories such as cash, jewelry, fragile goods, or high-value electronics. Check the baggage conditions before assuming that every item is covered. On an international trip, a special declaration of value or interest made when you check the bag, sometimes with an additional payment, may increase the airline's liability when that option is available. It generally can't be added after the bag disappears.

Expenses while a bag is delayed

If the airline has your bag but hasn't delivered it, ask about reimbursement for reasonable and necessary purchases. Toiletries, basic clothing, and similar essentials are more defensible than luxury or unusually expensive items.

Keep:

• Itemized receipts
• The date and location of each purchase
• The PIR number and other proof of the delay
• A short explanation of why each purchase was necessary
• Proof that you notified the airline

Some airlines use a daily allowance. That's a carrier-policy feature, not a guaranteed daily payment under the Montreal Convention. Ask whether the carrier requires pre-approval before making a costly purchase, and avoid spending beyond what you can reasonably justify.

When the bag is returned, submit an international delayed-baggage claim within 21 days after the date it was made available to you. Damage to the bag is subject to the separate 7-day complaint period.

What to do after the bag goes missing

1. Report it at the airport. Visit the baggage service desk before leaving and obtain the PIR number. If no desk is available, use the airline's immediate online or telephone reporting channel.
2. Save the travel records. Keep your boarding pass, itinerary, baggage-tag receipt, delivery address, and photographs of the bag.
3. Send written notice. Use the airline's claim portal or email. Identify the bag as missing, delayed, damaged, or missing contents, and save the submission confirmation.
4. Buy only practical essentials. Keep every itemized receipt and note why the purchase was needed.
5. Track the file. Record PIR updates, calls, emails, and any delivery promises. Keep the claim reference separate from the PIR if the airline gives you both.
6. Prepare an inventory if the bag is treated as lost. List each item, its approximate purchase date, original cost, and current value. On a qualifying international trip, do this once the bag reaches the 21-day point or the airline declares it lost earlier. For a domestic flight, ask the carrier when it will accept the inventory.
7. Notify your travel insurer. Insurance has separate deadlines, deductibles, sublimits, and exclusions. Tell the insurer about any airline payment so the same loss isn't recovered twice.
8. Ask for a written decision. If the airline reduces or denies the claim, ask it to identify the policy clause, valuation method, and evidence on which it relied.

Airline procedures can be stricter than the general legal framework. For example, KLM's delayed-baggage instructions say that passengers can report online within 48 hours in most destinations, with an exception for the United Kingdom on that page. The instructions also refer to a 21-day period for certain requests after the bag is received and a 7-day period for damage reports. Those are KLM's procedures, not universal deadlines for every airline.

KLM also says it locates about 90% of delayed bags within three days. That is an airline service statistic, not a legal deadline or a promise that applies to a particular bag.

If you missed a deadline

You never filed a PIR

Report the problem and send the written claim now. Include the baggage-tag number, flight details, delivery address, and a straightforward explanation of why the report was late. Not having a PIR makes the claim harder to prove, but it doesn't prevent you from asking the carrier to investigate.

You missed the 7-day damage or 21-day delay period

Submit the claim anyway and explain the reason for the delay. Ask the airline to accept the late complaint and give you a written decision if it refuses.

For international carriage, missing the Montreal Convention's written-complaint period can seriously weaken or bar the claim. The Convention's two-year court period doesn't automatically fix a missed Article 31 notice deadline. A substantial claim may require advice based on the particular itinerary and facts.

You think you missed the 21-day lost-bag deadline

Day 21 generally isn't the deadline to begin a lost-baggage claim under Montreal. It is the point at which non-delivery can generally be treated as loss. Contact the carrier, ask whether it has declared the bag lost, and submit the detailed inventory immediately.

For a U.S. domestic flight, ignore the international day-21 assumption. Ask the carrier when it will convert the trace into a lost-baggage valuation claim and check the filing term in its contract.

More than 2 years have passed

Article 35 of the Montreal Convention generally extinguishes the right to bring an action for damages after 2 years. An insurance policy or a domestic claim may have a different, often earlier, deadline. Check those terms immediately and preserve all correspondence.

Escalating an unresolved claim

Begin with the airline's baggage-claims team. If that doesn't resolve the issue, use the carrier's customer-relations or executive-resolution process. A focused appeal should include:

• PIR and claim numbers
• Flight date, route, and baggage-tag number
• The deadline you believe applies
• The amount requested and how you calculated it
• Receipts and other proof of ownership or value
• The airline's reason for reducing or denying payment
• A date by which you would like a response

For a U.S. airline or a flight covered by U.S. consumer rules, you can also complain to the U.S. Department of Transportation. A DOT complaint may help identify a regulatory problem, but it isn't a guaranteed award of the private claim.

Travel insurance is a separate route, not a substitute for reporting the loss to the airline. If the amount is significant and the airline won't resolve the matter, check the court deadline and consider jurisdiction-specific legal advice before it expires.

Frequently asked questions

Is 21 days the deadline to claim lost baggage?

Usually not. On qualifying international carriage, 21 days generally marks when an undelivered bag can be treated as lost. Send the formal claim as soon as the airline declares the bag lost or the 21-day point passes. U.S. domestic flights don't have a universal federal day-21 rule.

Is a PIR the same as a compensation claim?

No. A PIR opens the baggage trace. You may still need a separate written claim with receipts, an inventory, and proof of value.

Can you claim without receipts?

You can submit photographs, purchase records, card statements, warranty documents, and a reasonable written valuation. Without receipts, the airline may dispute both ownership and the amount claimed.

Does EU261 provide a fixed payment for a lost bag?

Generally, no. Baggage claims are usually governed by the Montreal Convention or another applicable baggage rule, rather than the fixed flight-disruption payments associated with EU261.

If your bag is missing now, file the PIR and written notice today, then save the confirmation and every receipt.