Baggage fees are where a cheap fare turns expensive. The headline price is for the seat; the bag is sold separately on most airlines now. This is how the system actually works, what it costs, and the few cases where you have real leverage.
The three bag tiers
Every airline sorts your luggage into one of three buckets:
- Personal item - small bag under the seat. Typical limit 40 x 25 x 20 cm. Included in every fare class.
- Carry-on - cabin bag in the overhead bin. Typical limit 55 x 40 x 23 cm and 7-10 kg. Included on legacy carriers, extra on low-cost.
- Checked - in the hold. Typical 20-23 kg per piece in economy, 32 kg in premium cabins. Hard weight cap; over-limit fees are punishing.
The exact dimensions vary by carrier - always check the operating airline\'s page before you pack.
Why bag fees exist
Unbundled fares. The airline industry split the seat from everything else in the early 2010s so it could advertise lower headline prices in metasearch results. The cheapest fare class (often called "Basic" or "Light") includes the smallest bag option only. Want a cabin bag? That is the next fare class up, or a paid add-on. The cheapest total cost is often not the cheapest fare - factor in the bag you need before comparing.
Carry-on sizing - how it is really enforced
Ryanair, Wizz Air, easyJet, Spirit, and Frontier all use a metal gate sizer and check selectively. If your bag does not fit, you pay a fee that usually exceeds the value of the ticket itself. Legacy carriers (BA, Lufthansa, AA, Delta) check less often but enforce harder when flights are full and overhead bins fill up. Two safety rules: pack to the smallest carrier on your trip, and weigh your bag at home - many airlines have a 7-8 kg cabin weight limit that travellers ignore until check-in.
Connections - when bags transfer and when they do not
A single booking reference with one airline (or one alliance using interline agreements) almost always through-checks bags to your final destination. Self-built connections - two separate tickets, often on different airlines - generally do not. You collect, clear, and re-check. This matters for two reasons: you need to budget at least three hours between flights, and you have to be inside the bag rules of the second airline (which may be stricter). On international-to-domestic connections in the US, Canada, and Australia, you collect and re-check even on a single ticket because of immigration rules.
Lost, damaged, and delayed bags - your rights
For international flights, the Montreal Convention caps airline liability at roughly 1,288 SDR (about USD 1,700) per passenger. The process: report at the airline desk before leaving the arrivals hall, get a Property Irregularity Report (PIR) reference, and keep it. For delayed bags, most airlines reimburse "reasonable" interim purchases (toiletries, a change of clothes) against receipts. For lost or damaged bags, claim in writing within 7 days for damage, 21 days for delay. Credit card travel insurance and standalone travel insurance can fill the gap above the airline\'s cap.
Two patterns worth knowing
Low-cost long-haul. Norse, French Bee, Scoot, AirAsia X - the long-haul low-cost model. The base fare excludes both cabin and checked bags. Add bags during booking, never at the airport (the gap is often 3-5x). Hidden inclusions on flag carriers. Some legacy airlines still include a checked bag on transatlantic and Asia routes by default. Compare not just price but what is included before assuming a low-cost is cheaper.
Frequently asked
What is the difference between a personal item, carry-on, and checked bag?
A personal item is a small bag that fits under the seat in front - usually a laptop bag or small backpack. A carry-on is a larger bag (typical limit 55 x 40 x 23 cm and 7-10 kg) that goes in the overhead bin. A checked bag is anything handed over at the counter and loaded into the hold - usually 20-32 kg. Most legacy airlines include all three on transatlantic routes; low-cost carriers include only the personal item by default.
Are carry-on size limits actually enforced?
On low-cost airlines, yes - they use gate sizers and charge a fee that often exceeds the original ticket if your bag does not fit. On legacy carriers enforcement is patchier and usually triggered when the flight is full. Always pack to the smallest carrier on your itinerary, not the most generous, especially with codeshares.
Will my bag transfer automatically on a connecting flight?
Only if the legs share a single ticket (one booking reference, one airline or alliance). Separate tickets - even on the same airline - generally mean you collect your bag, clear customs and immigration, and re-check at the next counter. Allow at least three hours for the transfer.
What happens if my checked bag is lost or damaged?
For international flights covered by the Montreal Convention, airlines are liable up to roughly 1,288 SDR (about USD 1,700) per passenger for lost, damaged, or delayed bags. File a PIR (Property Irregularity Report) before leaving the airport - without it your claim is much harder. Keep receipts for emergency purchases if your bag is delayed.
Pack smarter, pay less. Search flights with the bag count you actually need, compare airline policies, or read our cheap flights tactics.
