A search for “tsa guide lines” usually comes down to a practical question: can a particular item go through airport security in a carry-on bag? For flights departing from the United States, TSA rules determine what may pass the checkpoint, but they don’t replace an airline’s baggage limits or the laws of your destination. Check liquids, medications, batteries and anything sharp before packing, then confirm any item you’re unsure about with the TSA’s “What Can I Bring?” tool. Screening procedures can vary by airport and lane, so pack to make inspection straightforward and follow the directions of the officers on duty.
The Transportation Security Administration screens passengers and bags at U.S. airport security checkpoints. Its rules help determine whether an item can travel in your carry-on, must go in checked baggage, or is prohibited. A TSA officer may also inspect a bag or item more closely during screening.
Passing security does not settle every baggage question. Airlines set their own rules for carry-on bag size, weight, number of bags and some restricted articles. The laws of your destination may impose additional limits. These distinctions matter especially on international trips: TSA rules apply at the U.S. checkpoint, while a connecting airport may screen you under different procedures.
Use TSA guidance to check security restrictions, then check your airline’s baggage policy for the flight itself. If your itinerary includes a connection, allow for the possibility of another security check and avoid packing an item in a way that depends on it staying in your bag throughout the journey.
The table below covers frequent packing questions. It’s a starting point rather than a substitute for checking an unusual, high-value or regulated item individually.
| Item | Carry-on guidance | What to do before packing |
|---|---|---|
| Water and other drinks | Containers over 3.4 ounces generally cannot pass through the checkpoint, unless an exception applies. | Bring an empty reusable bottle or buy a drink after screening. Pack larger permitted containers in checked baggage. |
| Solid food and spreads | Solid foods are generally allowed. Foods that pour, spread or resemble liquids are subject to liquid limits. | Check items such as yogurt, sauces, dips and peanut butter in the TSA item tool. |
| Medication | Medically necessary liquids may be allowed in quantities above the standard limit, subject to screening. | Keep medication accessible and tell the officer if you’re carrying an exempt liquid. |
| Laptop or tablet | Generally permitted, but screening instructions depend on the lane and equipment. | Keep devices easy to reach in case an officer asks you to remove one. |
| Power bank or spare lithium battery | Spare batteries and power banks generally belong in carry-on baggage, not checked baggage. | Check the battery rating and your airline’s limits, especially for larger batteries. |
| Firearm | Firearms are not allowed in carry-on bags. | If transporting one, check TSA and airline rules for checked baggage, declaration and secure packaging before travelling. |
The familiar 3-1-1 rule applies to liquids, gels, aerosols, creams and pastes in carry-on baggage. Each container must hold no more than 3.4 ounces (100 milliliters), and the containers must fit in one quart-size bag. The limit applies to the container’s capacity, not just how much liquid remains inside it.
Think beyond toiletries. Drinks, liquid cosmetics, gels, spreads and some foods can all be subject to the rule. Solid snacks are generally easier to bring through, while foods such as soup, dressing or a soft spread may be treated as liquids. When classification isn’t obvious, search for the specific food or product rather than relying on its packaging label.
Medically necessary liquids and certain items for infants and children, such as breast milk, formula and baby food, may be allowed in quantities above the standard limit. They still require screening. Keep them separate and tell the TSA officer about them when you reach the checkpoint. Ice packs or cooling accessories used with these items may also be screened.
Pack essential medication where you can reach it, rather than burying it under other luggage. If you’re carrying liquid medication that exceeds the usual limit, declare it to the officer so it can be screened appropriately. Pills and medical supplies may also receive additional inspection; follow the officer’s directions and allow time for that possibility.
If you use a mobility aid, medical device or other equipment, tell the officer what assistance or screening arrangement you need. You can contact TSA Cares before travelling to ask about the screening process. For a device with removable parts, batteries or accessories, check both TSA guidance and the airline’s requirements before packing.
Laptops, tablets and other large electronics are generally permitted in carry-on bags. Whether you need to remove a device depends on the checkpoint lane and screening equipment, so follow the signs and instructions rather than assuming the same procedure at every airport. Keeping electronics accessible makes it easier to respond without unpacking the whole bag.
Power banks and spare lithium batteries generally need to travel in carry-on baggage. Restrictions can depend on the battery’s capacity, and airlines may have additional requirements. Check the rating printed on the battery and confirm the applicable rules if it is unusually large or you’re carrying several. Don’t put spare batteries in checked luggage unless the relevant rules specifically permit it.
Sharp objects, tools, sporting equipment and self-defense items can be difficult to assess from a broad category name. A small tool, for example, may be treated differently from a larger one, and an item that cannot go in a carry-on may still be permitted in checked baggage under specific conditions. Search for the exact item in the TSA tool and confirm your airline’s checked-baggage requirements before packing it.
Firearms require particular care. They cannot be carried through the checkpoint in a carry-on bag. If you plan to transport a firearm in checked baggage, review TSA and airline instructions well in advance; requirements include secure handling and declaring it to the airline. State and destination laws may also apply. If you haven’t confirmed the requirements, don’t take it to the checkpoint expecting to sort out the issue there.
Do not assume that an item will be allowed simply because it has passed through security on a previous trip. Equipment, packaging and screening decisions can differ, and the final decision at the checkpoint rests with TSA officers. Check the item again when in doubt.
Keep in mind that TSA screening is not the place to plan a last-minute change from carry-on to checked baggage. Once you reach security, you may not be able to retrieve a checked bag or return to the airline counter in time. If an item could be restricted, resolve where it belongs before leaving for the airport.
Screening instructions can vary with the airport, lane and equipment. Some passengers may be asked to remove shoes, outerwear or electronics; others may receive different instructions. Follow the directions given at your checkpoint rather than relying on what happened on an earlier trip.
TSA PreCheck provides eligible travellers with access to expedited screening when the appropriate indicator appears on their boarding pass. The process may allow certain items to remain packed or worn, but it doesn’t exempt you from screening or guarantee identical treatment at every checkpoint. Check that your passenger details are correct when booking and confirm that the benefit is shown on your boarding pass.
For international itineraries, a connection can introduce a second screening checkpoint, even if you have already passed through security in the United States. Liquids purchased after the first checkpoint may be subject to screening again, depending on the connection and local rules. Keep important medication and travel documents accessible, and avoid relying on an item being exempt at every airport on your route.
Stay with your bag and follow the officer’s directions. An officer may ask to inspect an item, explain what cannot pass through, or give you options based on the situation. If you’re unsure why an item was flagged, ask politely before moving or reaching into your bag.
There may be limited ways to resolve the problem once you’re at the checkpoint. Depending on the item and airport, you might be able to return it to someone outside security, arrange another option or choose not to travel with it. Don’t assume you can simply transfer it to checked baggage at that point. If an item is important, checking it before you leave home is the safer plan.
An empty reusable bottle can generally pass through screening. Fill it after the checkpoint, or buy a drink once you’re through. A bottle containing liquid is subject to the carry-on liquid limits unless an exception applies.
It depends on the screening lane and the instructions at your airport. Keep your laptop accessible and remove it only if signs or an officer ask you to.
Solid foods are generally permitted, while foods that are liquid, spreadable or pourable may fall under the 3-1-1 limit. Check the specific item if its texture makes the rule unclear, and consider additional restrictions for international travel.
Medically necessary liquids may be allowed in quantities above the standard carry-on limit, but they still need to be screened. Keep the medication accessible and tell the TSA officer about it. Check the TSA’s current instructions for your particular medication or medical supply.
No. TSA guidance concerns security screening, while airlines set baggage size limits and may impose additional restrictions. Your destination may have separate rules, too, so check all three before travelling with an unusual item.
The most useful TSA guide lines are the ones applied to the specific items in your bag. Check liquids, medical supplies, batteries and anything sharp in advance; confirm the airline’s baggage rules separately; and pack so that a closer inspection won’t disrupt everything else. For an uncertain item, use the TSA’s “What Can I Bring?” tool before you head to the airport.
