If a U.S. airline loses your checked bag, report it before leaving the airport and send a written claim with proof. Start the paper trail immediately.

Compensation usually covers reasonable, documented financial loss. It isn't a flat daily payment. A separate federal rule can also return the checked-bag fee after a qualifying significant delay or loss.

Domestic U.S. trips and international carriage use different limits. This guide focuses on U.S. consumers while explaining when the Montreal Convention changes the deadline or cap.

The DOT's guidance on lost, delayed, or damaged baggage and the eCFR text of 14 CFR 260.5 are useful starting points.

Which rule applies to your flight?

Start with the itinerary shown on your ticket. A bag that disappears during a domestic connection may still fall under international rules if the journey is part of one international contract of carriage.

An airline contract can set procedures and exclusions, but it can't remove mandatory federal or treaty protections.

Turns out, IATA is not a regulator and doesn't decide individual claims. Its tracking systems and industry standards may help locate a bag, but they don't create a payment right. EU261 is also different: it mainly covers flight disruptions, not a fixed payment for lost baggage.

What lost baggage compensation can cover

For a domestic itinerary, an airline generally must pay reasonable, verifiable, actual loss caused by delayed, damaged, or lost baggage, subject to the liability limit. The $4,700 figure is a ceiling, not an automatic award.

A delayed bag can support a claim for necessary clothing, toiletries, or other reasonable replacement items. Keep purchases modest. A replacement for an immediate need is easier to justify than an upgraded wardrobe.

Damage is usually handled through a reasonable repair cost or the item's value after considering age and condition. Once a bag is treated as lost, the claim normally focuses on the depreciated value of the bag and its contents, not the cost of buying everything new.

For international carriage covered by the Montreal Convention, the baggage limit is 1,519 Special Drawing Rights, or SDR, per passenger. The dollar equivalent changes, so don't rely on an old online conversion. A special declaration of value made before travel and accepted by the carrier may allow a higher declared limit.

Receipts matter. So does an honest inventory.

Deadlines that matter

The deadlines below are especially important for an international claim. Domestic U.S. reporting windows can come from the airline's contract, so check that document and report the problem promptly.

There is no universal federal four-hour airport-report rule for every U.S. baggage claim. Some airline contracts use their own reporting windows. Same-day notice is safest.

The airport report starts the record, but don't assume it is the complete written claim required for an international case. Send a separate email or online submission and save the confirmation, attachments, and timestamp.

Checked-bag fee refunds after a delay or loss

Under 14 CFR 260.5, a passenger who reports a lost or significantly delayed checked bag can qualify for an automatic refund of the checked-bag fee.

For most U.S. domestic trips, a bag is significantly delayed when it hasn't been delivered within 12 hours after the aircraft door opens at the final destination. For an international flight to or from the U.S., the usual thresholds are 15 hours for a flight scheduled to last 12 hours or less, and 30 hours for a longer flight.

The refund must be at least the fee paid to transport the bag. Thing is, it doesn't replace reimbursement for reasonable emergency purchases or the value of a lost bag. Request each amount separately.

The rule includes exceptions. They can include failing to collect and recheck a bag at the first U.S. international entry point when required by Customs and Border Protection, or voluntarily agreeing to travel without the checked bag on the same flight. The Federal Register explanation of the refund rule provides more detail.

A filing workflow that works

1. Report the problem at the airport. Go to the airline's baggage office. Ask for a property irregularity report or equivalent record, a reference number, and instructions for delivery or online follow-up.

2. Create written notice. Submit the claim through the airline's portal or by email as soon as possible. Include every flight number, the bag tag, the route, and your contact details.

3. Name every carrier involved. On a code-share or multi-airline trip, identify the operating carrier, ticketing carrier, and the desk that took your report. Start with the carrier that issued the report, then follow any written direction about where to send the claim.

4. Keep necessary spending reasonable. Buy only what you need while the bag is unavailable. Save itemized receipts and avoid purchases that look like upgrades.

5. Build the lost-bag claim if the bag remains missing. On a Montreal-covered itinerary, the 21-day point usually changes the claim from delayed baggage to lost baggage. Submit an itemized value claim immediately.

6. Follow up in writing. Keep the claim number in every message. Ask what evidence is missing and request a written explanation for any denial.

Evidence that makes a claim easier

Put everything in one folder. A long, winding email with scattered attachments is harder to review, so make one clean package with a short summary and numbered documents.

• Boarding pass, itinerary, baggage receipt, and bag tag
• Property irregularity report and delivery tracking number
• Photos of the bag, its contents, and any damage
• Itemized inventory showing purchase date, age, original price, and requested amount
• Receipts for replacement items, repair estimates, and credit-card statements when a receipt is missing
• Relevant airline messages, delivery notices, and screenshots from a tracker such as an AirTag

A tracker can show where a bag is. It doesn't prove what was inside or establish the value of the contents. Treat location data as supporting evidence.

Connections, families, and valuable items

One liability limit generally applies per passenger, not per suitcase. Several lost bags don't automatically create several international treaty limits. Family claims can involve separate passenger limits, but shared property and shared purchases may need a clear allocation.

Airlines may exclude or limit responsibility for cash, jewelry, fragile property, and other valuables in checked baggage under the contract of carriage. Read those terms before claiming an expensive item. A special declaration and additional payment may be required for higher declared value.

Don't inflate the inventory. List the item's age and condition, then request a defensible amount.

A plain-language claim template

Use this as a starting point. Replace the brackets and attach supporting documents.

Subject: Written baggage claim for PIR [number]

I am submitting a written claim for baggage connected with flight [number] on [date].

Passenger: [name]

Bag tag: [number]

PIR or claim reference: [number]

Bag status: [delayed, lost, or damaged]

I request $[amount] for the itemized loss and $[amount] for necessary expenses caused by the delay. I also request a refund of the checked-bag fee under 14 CFR 260.5, if that rule applies.

Attached are my itinerary, baggage documents, report, inventory, receipts, photographs, and other supporting records. Please confirm receipt and identify any missing information.

Regards,
[name and contact information]

For an international delayed claim, send the written notice within the 21-day period. For damage, use the 7-day period.

If the airline denies or ignores the claim

Ask for the specific reason. Common disputes involve missing receipts, depreciation, excluded items, unreasonable purchases, or disagreement about which carrier handled the bag.

Reply with one organized package instead of sending several disconnected messages. Point to the relevant document, correct any factual mistake, and ask for written reconsideration.

If the airline doesn't resolve a U.S.-covered complaint, use the complaint route linked from the DOT baggage guidance. A DOT complaint creates an official record and may prompt a response, but DOT does not act as your private damages calculator.

Don't let an administrative complaint run past a Montreal Convention deadline. A regulator complaint does not extend the treaty's two-year court limitation period.

Questions readers usually ask

Is there a four-hour federal deadline to report a missing bag?
No single federal rule imposes that deadline on every U.S. claim. Report the problem immediately and follow the airline's contract.

Is a PIR enough to preserve an international claim?
It may not be. Send a separate written claim and keep proof that the airline received it.

Can I claim both emergency purchases and the checked-bag fee?
Yes, if the expenses are reasonable and the fee-refund rule applies. They are separate parts of the claim.

Does an AirTag guarantee compensation?
No. It can support a location dispute, but it doesn't prove ownership, contents, or value.

When does delayed baggage become lost?
For Montreal-covered carriage, baggage not delivered within 21 days is generally treated as lost for claim purposes. An airline's earlier admission of loss can allow an earlier claim.

Your next move

Open the airline's baggage contract today. Put the report number, bag tag, ticket, inventory, receipts, and requested amounts into one submission, then calendar a follow-up before the applicable deadline.