Your checked bag did not come out. The carousel is empty. Should you wait overnight, or start the claim now?

Start it at the airport. The missing-bag report, often called a PIR, is the record later compensation sits on.

For most U.S. trips, two legal regimes matter. Domestic itineraries generally fall under Department of Transportation baggage liability. International tickets usually fall under the Montreal Convention. Airline claim pages and credit-card travel benefits sit on top as company policy. They don't replace those rules.

Thing is, a lot of advice mixes this with EU flight-delay law and IATA tracing standards. Those are different systems. IATA Resolution 753 is how airlines track bags among themselves. It is not a passenger compensation statute.

Which rule applies to your trip

Match the ticket before you argue about money.

If every segment is a U.S. domestic itinerary, DOT baggage liability is the usual ceiling. Industry explainers commonly put that domestic cap at $4,700 per passenger under 14 CFR Part 254. Most international itineraries, including a U.S. carrier flying abroad, use the Montreal Convention, which currently limits baggage liability to 1,519 Special Drawing Rights per passenger. The dollar figure moves with the SDR rate. Recent conversions land around $2,000 to $2,175.

Don't treat those figures as a guaranteed check. Carriers still want proof of what you packed. They often pay depreciated value, not the price of a brand-new replacement.

The U.S. Department of Transportation page on lost, delayed, or damaged baggage is the agency's own overview.

What those rules do not decide

An apology voucher or extra miles is goodwill. It does not reset a claim deadline or raise the liability cap.

Report the bag before you leave

Do this in the terminal if you can.

1. Go to the baggage desk and file a missing-bag report. Get the file number in writing.
2. Photograph remaining bag tags, your boarding pass, and the PIR or file ID.
3. Ask how they will trace the bag and how you will get updates.
4. Keep the PIR number, bag tags, and ticket together. You'll reuse them.
5. If you buy essentials, save itemized receipts from that day forward.

A phone memo is not enough. Get the airline's file ID.

Delayed bags and lost bags pay differently

A delayed bag is still in the system. A lost bag has not turned up after the carrier's waiting period.

On many international tickets, that waiting period lines up with the Montreal Convention's 21-day delay window. During a delay, you can ask to be reimbursed for reasonable necessities you actually bought because the bag was missing. Think a change of clothes, not a new wardrobe. Once the airline treats the bag as lost, the claim shifts toward the documented value of the contents, still capped by whichever liability rule applies to your ticket.

Waiting overnight to "make it lost" does not raise the cap. Filing the PIR and keeping receipts does the real work.

Checked-bag fees you may get back

Turns out the contents claim is not the only money in play.

Federal rule 14 CFR 260.5 requires covered carriers to refund checked-bag fees when a bag is lost or significantly delayed. The refund must be at least the fee you paid to transport that bag. The rule also describes passenger and carrier notices, and it provides for automatic refunds in the situations it lists.

This is a fee refund, not a second contents payout. If you paid $40 to check the suitcase, that $40 is its own line.

The rule lists exceptions, including a passenger who fails to pick up and recheck a bag at the first international U.S. entry point when required, and a passenger who agrees to travel without the checked bag on the same flight. If your trip involved a customs recheck, read that text before you assume the fee comes back.

File the formal claim even if the bag might appear

Use the airline's baggage-claim form. Portals beat a stray email if they give you one.

Put the flight date, route, ticket number, bag-tag numbers, and file ID at the top. List what was in the bag, with purchase dates and values. Attach the PIR, receipts, and photos. For delay expenses, follow the airline's published timeline. Some U.S. carriers ask for those receipts within 30 days of the delay.

International tickets have extra writing rules. A damage complaint generally must be in writing within 7 days after you receive the bag. A delay complaint generally must be in writing within 21 days after the bag is made available to you. IATA's Montreal Convention page outlines the treaty. It is not a claims office.

Follow up if the file goes quiet. Ask for a baggage-claims supervisor. Write down dates, names, and what they said they would do.

Proof that gets a number attached

Airlines do not pay a vague list that says "clothes and a laptop."

Name each item. Add when you bought it and what you paid. Receipts beat estimates. Serial numbers help with electronics. If you lack receipts, a card statement plus a photo is still better than a round number you guessed at the hotel desk.

Luxury items with no proof you packed them get cut. Late international complaints get cut too.

You will probably be tired, maybe still in yesterday's clothes, and the last thing you want is a spreadsheet of socks, but the people who later review your file were not at the carousel with you, they only have what you upload, so if you buy a charger and a cheap shirt that night, photograph the receipt before it fades in a pocket, and if the bag shows up on day three you still send those necessity receipts because a delay claim and a loss claim are not the same pile of money.

If they deny the claim or offer too little

Reply in writing. Restate the PIR number, the rule that matches your ticket, the dollar amount, and the attachments.

To be honest, thin first offers usually mean the inventory looked thin too. Send the missing receipts. Don't send a page of anger about the agent.

If the carrier still refuses, file a consumer complaint with the U.S. Department of Transportation. Covered airlines generally must acknowledge a written consumer complaint within 30 days and give a substantive written response within 60 days. That filing becomes part of the airline's complaint record. It is not a payment order.

Some credit cards include delayed or lost baggage coverage as a card benefit. Check that guide and its deadline. File there on a separate track if the benefit exists. The airline and the card issuer will not automatically coordinate.

Small claims court is a later option in many states. Fees, dollar limits, and arbitration clauses in the contract of carriage vary. This site cannot tell you whether to file a lawsuit.

A short claim letter

Keep names, numbers, and dollars in the first paragraph.

[Your name]
[Address]
[Date]

[Airline baggage claims]
Re: File ID [number], ticket [number], flight [number and date]

I am claiming for checked baggage that was [delayed / not delivered] on the flight above. I reported the bag at the airport under file ID [number].

The attached inventory lists contents and values, with receipts. I also attach the PIR, bag-tag photos, and necessity receipts totaling $[amount].

Under [14 CFR Part 254 / the Montreal Convention], I request $[amount] for documented contents and delay expenses. I also request a refund of the checked-bag fee I paid, as applicable under 14 CFR 260.5.

Please confirm in writing within 14 days. If we cannot resolve this, I will file a complaint with the U.S. Department of Transportation.

[Name]
[Phone]
[Email]

Cite the regime that actually matches the ticket. A domestic U.S. hop is not a Montreal claim just because the SDR number looks useful.

Tonight, pull the PIR number, bag tags, and receipts into one folder. File the airline claim with a contents list. If the file stalls, use the DOT baggage page and the complaint process, and open your card's benefits guide on the same day.