If your checked bag doesn't arrive, the single most important step is reporting it before you leave the airport, since a Property Irregularity Report (PIR) is what starts the airline's tracking and liability process — without one, a later claim becomes far harder to pursue. Most "lost" bags are actually just delayed and turn up within a few days, but airlines are only obliged to treat a bag as officially lost after a set waiting period, typically around 21 days, under the international rules that govern baggage liability.
What to do at the airport, immediately
- Go to the airline's baggage desk before leaving the arrivals area — usually near the baggage carousels — rather than discovering the problem after you've already left.
- File a Property Irregularity Report, which records your flight details, a description of the bag, and your contact and delivery address. Keep your copy and reference number.
- Ask about immediate essentials — many airlines provide a per-day allowance or reimbursement for basic items (toiletries, a change of clothes) while your bag is missing, though the amount and process vary by airline.
- Keep your boarding pass and baggage claim tag stub, since these are often needed to support the claim.
The first few days: delayed, not lost
The overwhelming majority of mishandled bags are found and delivered within a few days, often having simply missed a connection or been misrouted onto a later flight. Airlines typically use a shared international tracking system to locate delayed bags — often the same system that helps reunite a bag mishandled during a self-transfer connection — and will usually deliver a found bag directly to your address once it turns up, at no cost to you. During this period, keep receipts for anything you had to buy to get by — the interim expense allowance mentioned above is usually meant to cover exactly this kind of short-term gap.
Keep every receipt for essentials bought while your bag is missing — toiletries, a change of clothes, anything reasonably necessary. Airlines generally will not reimburse extravagant purchases, but reasonable, itemised expenses are the normal basis for an interim claim while the bag is still just "delayed" rather than formally lost.
The 21-day rule and when a bag counts as officially lost
Under the Montreal Convention — the international treaty governing airline liability for baggage on international flights — a bag is generally not considered legally "lost" until a set period has passed without it being found, commonly around 21 days, though airlines' own policies and the exact figure can vary slightly. Once that point passes, you can file a full loss claim for the bag's contents rather than just an interim expense claim, and the airline's liability shifts from "delayed baggage" compensation to the higher-value "lost baggage" claim process.
Montreal Convention liability limits
The Montreal Convention caps how much an airline is liable for per passenger for lost, delayed or damaged baggage on an international flight, expressed in a set number of Special Drawing Rights (an IMF-defined unit, roughly comparable to a basket of major currencies) — in practice this works out to a capped amount in the region of the equivalent of roughly €1,300–1,500, though the exact figure shifts with currency conversion and is periodically revised. This cap applies per passenger regardless of how many bags you checked or how much your belongings were actually worth, which is one of the more important things to understand before assuming a claim will cover everything lost.
If your checked bag contains anything of high value — electronics, jewellery, medical equipment — be aware the Montreal Convention cap may not come close to covering it. Airlines routinely exclude or limit liability further for cash, jewellery, electronics and fragile items in their own conditions of carriage, and don't assume standard baggage liability will make you whole. Comprehensive travel insurance with adequate baggage cover is the more reliable protection for genuinely valuable items, and carrying anything irreplaceable in cabin baggage rather than checking it is the safest approach of all.
This liability question is entirely separate from what happens if your bag simply fails to transfer during a tight connection — that's usually a delayed-baggage case resolved within days, not the lost-baggage claim process described below.
Filing the formal claim
- Submit the claim in writing to the airline, referencing your PIR number, generally within the time limit set by the airline's own policy (commonly a matter of days to a few weeks from when you first reported it, though a full loss claim can be filed once the waiting period passes).
- Itemise contents and approximate value as specifically as you reasonably can, since vague claims are more easily challenged or reduced.
- Keep proof of purchase or value where possible for higher-value items, though airlines generally accept a reasonable estimate for everyday items without needing a receipt for every single thing.
- Note the Montreal Convention cap when framing your expectations — claims for a bag's full contents are still subject to the per-passenger liability limit.
If your bag is damaged rather than lost
Damage claims follow a similar process to loss claims but generally need to be reported faster — often within a matter of days of collecting the bag — and are subject to the same Montreal Convention liability cap. Report visible damage at the airport before leaving if at all possible, since this creates an immediate record rather than relying on your account of what happened after the fact — the same principle as reporting a flight delay or cancellation promptly rather than raising it only once you're home. If your itinerary also has you clearing an automated passport gate on arrival, see our guide to e-gates and automated border control for what to expect at that stage of the journey.
Travel insurance as a backup
Given the Montreal Convention's per-passenger cap and the various exclusions airlines apply, travel insurance with baggage cover is worth having as a second layer of protection, particularly if you're travelling with valuable items or a full suitcase's worth of belongings that could plausibly exceed the airline's liability limit. Check your policy's own baggage-specific sub-limits and exclusions — insurance policies often have their own caps on individual high-value items (a laptop, jewellery) that are lower than the policy's total baggage limit.
Frequently asked questions
How long before an airline considers my bag officially lost?
Commonly around 21 days without it being found, under the general practice tied to the Montreal Convention, though this can vary slightly by airline — check the specific carrier's stated policy.
What's the maximum an airline has to pay for a lost bag?
The Montreal Convention sets a per-passenger liability cap for international flights, in the region of the equivalent of roughly €1,300–1,500, regardless of how many bags you checked or their actual value — always check current figures, since they're periodically revised.
Should I report a missing bag immediately or wait to see if it turns up?
Report it immediately, before leaving the airport. Filing a Property Irregularity Report is what starts the airline's tracking process and protects your ability to claim later, even though most delayed bags do turn up within a few days.
Does travel insurance cover more than the airline's baggage liability?
It can, and is worth having as a second layer, particularly for valuable items — but check your specific policy's sub-limits and exclusions, since insurers often cap individual high-value items separately from the overall baggage limit.
Sources and further reading:
- The Montreal Convention (1999) for the international framework on airline baggage liability.
- IATA for background on baggage handling standards and airline liability practice.
- Individual airline conditions of carriage for specific PIR, claims windows and exclusions.