Checked baggage rules on U.S. flights come from the Transportation Security Administration and the Federal Aviation Administration, and they differ from carry-on rules in important ways. Some items are banned outright, some need specific packaging or a declaration to the airline, and battery rules alone catch thousands of travelers a year. Fines start in the hundreds and reach the thousands, with criminal referrals for the worst violations.
What You Cannot Pack in a Checked Bag
A short list of materials is off-limits no matter how you package them. Explosives such as dynamite, fireworks, and blasting caps are banned. So are all flammable liquid fuels, including gasoline, lighter fluid, and cooking fuel.1Transportation Security Administration. What Can I Bring – Complete List Strike-anywhere matches are prohibited in both checked and carry-on bags; safety matches (the kind that need the strip on the box) are allowed only in carry-on.
Personal compressed oxygen is banned in checked and carry-on bags on U.S. flights, whether the cylinder is full, partially used, or empty.2Federal Aviation Administration. PackSafe – Oxygen Compressed or Liquid If you need oxygen during a flight, the airline supplies it. Most carriers want advance notice and charge a fee.
Damaged, defective, or recalled lithium batteries cannot go in checked or carry-on bags at all.3Federal Aviation Administration. Lithium Batteries in Baggage A failing lithium cell can enter thermal runaway and start a fire that cargo hold suppression systems cannot put out. If a battery looks swollen, cracked, or overheating, or if the device is under a recall, leave it home.
Batteries and Electronics
Laptops, cameras, and similar electronics can go in checked bags, but they must be fully powered off (not in sleep mode) and protected against accidental activation.4eCFR. 49 CFR 175.10 – Exceptions for Passengers, Crewmembers, and Air Operators Each installed lithium ion battery must be 100 watt-hours or less; each lithium metal battery must contain no more than 2 grams of lithium. Larger batteries (up to 160 Wh lithium ion or 8 grams lithium metal) require airline approval, cabin-only carriage, and are capped at two spares per person.
The rule most travelers miss: spare and loose lithium batteries are never allowed in checked luggage. That covers portable chargers, power banks, phone battery cases, and e-cigarettes. All of them must stay with you in the cabin.3Federal Aviation Administration. Lithium Batteries in Baggage If a gate agent asks to check your carry-on at the last minute, pull those items out first.
Smart Luggage
A suitcase with a built-in lithium battery (for GPS, USB charging, or motorized wheels) can be checked only if the battery is removable. Take it out before check-in and carry it on. Many airlines will refuse a smart bag with a non-removable battery.4eCFR. 49 CFR 175.10 – Exceptions for Passengers, Crewmembers, and Air Operators
AirTags and Bluetooth Trackers
Small Bluetooth trackers like Apple AirTags are allowed in checked bags. Federal rules exempt devices with lithium metal batteries of 0.3 grams or less from the stricter checked-baggage restrictions, and most consumer trackers sit well below that.4eCFR. 49 CFR 175.10 – Exceptions for Passengers, Crewmembers, and Air Operators Check the lithium content on any larger GPS device before packing it.
Firearms and Ammunition
Firearms are allowed in checked baggage if you follow every requirement below. Miss one and the airline will refuse the bag, or TSA will fine you.
- The firearm is completely unloaded, with nothing in the chamber, cylinder, or any inserted magazine.
- It is packed in a hard-sided case built to prevent unauthorized access.
- The case is locked, and only you hold the key or combination. TSA-recognized locks are not appropriate here; nobody but you should be able to open it.
- You declare the firearm to the airline agent at check-in, either orally or in writing, before handing over the bag.
After you declare, the airline puts a declaration form on top of or inside the case.6Transportation Security Administration. Traveling With Your Firearm Ammunition can travel in the same checked bag, and even in the same container as the firearm, but only in packaging designed for it: the original box, or a fiber, wood, or metal container.7eCFR. 49 CFR 1544.203 – Acceptance and Screening of Checked Baggage
Failing to declare is where travelers get into real trouble. An undeclared loaded firearm carries a fine of $1,700 to $3,410 and a criminal referral. An undeclared unloaded firearm can bring fines of $850 to $1,700 on a repeat offense, though TSA may issue a warning for a first violation.8Transportation Security Administration. Civil Enforcement
Alcohol, Dry Ice, and Other Regulated Items
Alcohol
Rules track the alcohol content. Beverages at 24 percent alcohol by volume or below (beer and most wine) have no quantity limit in checked bags. Spirits between 24 and 70 percent alcohol are capped at 5 liters per passenger and must be in unopened retail packaging. Anything above 70 percent (140 proof) is banned from both checked and carry-on bags.9Transportation Security Administration. Alcoholic Beverages
Dry Ice
Dry ice is allowed in checked bags for keeping perishables cold, up to 5.5 pounds per passenger. The container must be ventilated so carbon dioxide gas can escape, and the package must be marked “dry ice” or “carbon dioxide, solid” with the net weight.10Federal Aviation Administration. PackSafe – Dry Ice You also need airline approval, so call ahead.11Transportation Security Administration. Dry Ice
Fueled Tools and Engines
Chainsaws, weed trimmers, generators, and other tools with internal combustion engines can be checked only under narrow conditions. Fuel tank and fuel lines must be drained, cleaned of residue, and purged of vapors so no liquid fuel leaks at any angle. The tool cannot contain a wet battery, sodium battery, or lithium battery.4eCFR. 49 CFR 175.10 – Exceptions for Passengers, Crewmembers, and Air Operators Meeting every condition is hard enough that most travelers ship these items instead.
Liquid Medications
Non-flammable liquid medications have no volume limit in checked bags.12Transportation Security Administration. Medications Liquid The 3.4-ounce carry-on limit does not apply. Pack them so they cannot leak, and keep a backup supply in your carry-on in case the checked bag is delayed.
Size, Weight, and Baggage Fees
TSA does not set size or weight limits; airlines do. The standard economy limit at most U.S. carriers is 62 linear inches (length + width + height) and 50 pounds. First and business class often allows up to 70 pounds. Overweight or oversized fees typically start around $30 and can climb past $200.
Airlines have to tell you what those fees are before you buy the ticket. A Department of Transportation rule requires airlines and ticket agents to disclose first checked bag, second checked bag, and carry-on fees during booking, including any personalized rates tied to loyalty status, military status, or a co-branded credit card.13U.S. Department of Transportation. Final Rule – Enhancing Transparency of Airline Ancillary Service Fees
Musical Instruments
Airlines are federally required to accept a musical instrument as checked baggage if total dimensions (including the case) do not exceed 150 linear inches and total weight stays under 165 pounds.14eCFR. 14 CFR Part 251 – Carriage of Musical Instruments Standard checked and oversize fees still apply, but the airline cannot refuse the instrument within those limits. Smaller instruments can also travel in the cabin if you buy them a seat.
Penalties for Packing the Wrong Thing
Fines depend on what TSA finds. Undeclared loaded firearm: $1,700 to $3,410, plus a criminal referral. Explosive materials: $10,230 to $17,062, plus a criminal referral. Flammable liquids like gasoline or lighter fluid: $450 to $2,570.8Transportation Security Administration. Civil Enforcement These are passenger-level penalties. Even outside the firearm and explosives categories, the numbers are high enough to make a careful pre-flight check worthwhile.
If Your Bag Is Opened or Damaged
TSA screens every checked bag. If the automated scan flags something it cannot resolve, an officer opens the bag in a monitored area, examines the item, and places a Notice of Baggage Inspection inside before closing it.15Transportation Security Administration. Security Screening Finding that notice when you unpack is routine.
Using a TSA-recognized lock lets screeners open and relock your bag with a universal key. You are not required to use one, but a standard lock that blocks access will be cut off, and TSA is not liable for that damage.15Transportation Security Administration. Security Screening
If TSA damages your property or something goes missing during screening, you can file a claim under the Federal Tort Claims Act using Standard Form 95. The form asks for a written description, a specific dollar amount, and supporting evidence (receipts, photos, repair estimates).16Transportation Security Administration. Claims You have two years from the incident to file, and missing the deadline generally kills the claim.17Transportation Security Administration. SF 95 TSA Tort Claim Package TSA has up to six months to investigate; if it denies the claim or does not respond within that window, you can sue in federal district court.
Damage or loss during loading, transport, or delivery is the airline’s problem, not TSA’s, and you file with the carrier. Federal rules require domestic airlines to accept liability of at least $4,700 per passenger for lost, damaged, or delayed baggage.18eCFR. 14 CFR Part 254 – Domestic Baggage Liability That is a floor, not a cap, but you will need documentation to prove what the items were worth.