July 21, 2026
How Baggage Routing Works: From Tag to Carousel
That three-letter code on your baggage tag determines exactly how your bag travels through the global aviation system. Here is what happens between check-in and baggage claim.
When you check a bag, it receives a paper baggage tag printed with a barcode and — prominently — a three-letter destination airport code. That tag is not just for humans to read. It drives an automated system that routes your bag through sorting facilities, aircraft holds, and transfer areas across the entire journey.
The baggage tag anatomy
A baggage tag contains several key pieces of information:
- Destination airport code — the final destination IATA code (e.g., CDG for Paris)
- Flight number — the specific flight the bag is booked on
- Bag sequence number — a unique identifier linking the bag to the passenger record
- Barcode — scanned at each handling point to track the bag's location
Automated baggage systems
Major airports use highly automated baggage handling systems that read barcode tags as bags travel on conveyor belts and sort them to the correct departure gate or arrival carousel. Frankfurt Airport's baggage system handles over 100,000 bags per day through a network of conveyor belts totaling over 60 kilometers.
When the code matters most
The destination code becomes critical for connecting itineraries. A bag checked from Boston (BOS) through London Heathrow (LHR) to Rome (FCO) is tagged to FCO — the system at LHR must identify it as a transfer bag and route it to the Rome flight rather than to baggage claim. This is why minimum connection times exist: the system needs time to physically move the bag from the arriving aircraft to the departing one.