If you discover that items are missing from your checked luggage, you must act quickly, as many airlines have strict reporting windows (often as short as 24 hours for domestic flights). First, report the theft to the airline's baggage office before leaving the airport to obtain a Property Irregularity Report (PIR). If you are already home, file a claim through their website immediately. Next, if you are in the U.S., file a claim with the TSA, as they handle the screening process. You should also file a police report at the airport precinct to create an official record, which is often required for private travel insurance or homeowners' insurance claims. Provide photos of your suitcase, receipts for the stolen items, and your baggage tag. Note that airlines have "maximum liability" limits (around $3,800 in the U.S. and approx. $1,700 internationally under the Montreal Convention), and they often exclude high-value items like jewelry or electronics from coverage, so checking your personal insurance is a crucial final step.