What are my rights if the airline loses my luggage?

Checked baggage on international journeys is governed by the Montreal Convention 1999, retained in UK law after Brexit. For a lost checked bag it imposes strict liability: you only have to show the bag was checked in and never came back, not that the airline did anything wrong. For damage and delay the airline can escape liability, but only by proving it took all reasonable measures.

The deadlines that can kill a claim

• Before you leave the airport: report the bag at the airline's baggage desk and get a Property Irregularity Report reference. Without a PIR the claim is very hard to run. If no desk is staffed, report online or by phone and record the time and who you spoke to.
• Damaged bag — 7 days from the day you received it, to complain in writing.
• Delayed bag — 21 days from the day it finally reached you.
• Lost bag: airlines usually declare a bag officially lost after 21 days, and you then submit a full loss claim quoting the PIR.
• Court claim — two years from the date you arrived, or should have arrived.

Send complaints by email with a read receipt or by recorded post, quoting the PIR reference, flight details, an itemised list of contents with values, and photographs of any damage. The deadline runs whether or not the airline has been in touch.

What you can actually recover

The cap of 1,288 Special Drawing Rights — about £1,300, moving with exchange rates — is a ceiling, not an entitlement. Within it you can claim the depreciated value of lost or damaged items rather than what you paid for them, the essential purchases you had to make while waiting, and costs flowing directly from the loss, such as hiring formal wear for an event. Airlines routinely exclude jewellery, cash, passports and electronics from checked-bag claims, limit liability for fragile items, and argue damage was pre-existing — so carry valuables in hand luggage and photograph your bags before check-in. To go above the cap you must declare excess value at check-in and pay the supplement.

You do not have to take a small fixed offer; accepting one usually means signing away the rest. Reject it in writing and escalate to a CAA-approved ADR body or the county court. On a purely domestic UK flight the Convention does not apply — the airline's conditions of carriage and the Consumer Rights Act 2015 govern instead.