The rules for what travelers can bring through a U.S. airport security checkpoint combine Transportation Security Administration (TSA) screening requirements with separate limits that individual airlines have added for batteries. Understanding both layers helps avoid delays or having an item taken away at the checkpoint.
The 3-1-1 liquids rule
Liquids, gels, creams, pastes and aerosols carried through the checkpoint must each be in a container of 3.4 ounces (100 ml) or less, and all of a traveler's containers must fit inside one quart-size, clear, zip-top bag, with one such bag allowed per passenger, according to the rule as summarized by TSA-focused travel site securitywaittimes.com. Medications and baby formula or breast milk are treated as exceptions and can exceed the 3.4-ounce limit when declared to an officer.
Solid foods and solid toiletries are not covered by the liquids rule. Items such as sandwiches, bread, whole fruit, nuts, chips and solid cosmetics can travel in a carry-on without the quart-bag restriction, per the same source.
Shoes, laptops and the checkpoint routine
Since July 2025, most travelers no longer have to remove their shoes at standard security screening. U.S. Secretary of Homeland Security Kristi Noem announced the change on July 9, 2025, at Ronald Reagan Washington National Airport, citing improvements in screening technology, according to The Points Guy. The outlet reported Noem said the shift would help streamline checkpoints ahead of large events such as the 2026 FIFA World Cup and the 2028 Los Angeles Olympics.
Shoe removal can still be required for passengers selected for secondary screening or those without a REAL ID-compliant identification document, The Points Guy reported. The underlying shoe-removal policy had been in place for nearly 19 years, introduced after a 2001 attempted shoe-bombing incident.
Power banks and spare batteries
Spare lithium-ion batteries and portable chargers (power banks) must travel in carry-on luggage, not in checked bags, because thermal faults are harder to detect and manage in a cargo hold, according to securitywaittimes.com. Devices with batteries already installed, such as phones or laptops, can go in either carry-on or checked bags, though checked units must be fully powered off.
On top of the TSA's cabin-only rule, several U.S. airlines are adding their own limits in 2026, citing a rise in battery fire incidents described as thermal runaway. American Airlines will cap passengers at two lithium-battery devices, each under 100 watt-hours, starting May 1, 2026, with the items kept in the cabin, according to a report by Yahoo Creators. The same report said Southwest Airlines requires any power bank in use to stay out of a bag and in plain sight, while Delta allows batteries up to 100 Wh without prior approval and up to two batteries between 101 and 160 Wh with approval, and requires them switched off during takeoff and landing.
Battery limits by airline (as reported, 2026)| Airline | Limit without approval | Approval-required range | Notes |
|---|
| American Airlines | 2 devices, under 100 Wh each | — | Carry-on only, effective May 1, 2026 — Yahoo Creators |
|---|
| United Airlines | Up to 2 spare batteries, up to 160 Wh | 101–160 Wh needs approval | Carry-on only — Yahoo Creators |
|---|
| Delta Air Lines | Up to 100 Wh | 101–160 Wh, max 2, needs approval | Must be off during takeoff/landing — Yahoo Creators |
|---|
| Southwest Airlines | 1 charger, under 100 Wh | — | Must remain visible when in use — Yahoo Creators |
|---|
What's prohibited in carry-on bags
- Full-size liquids over 3.4 ounces per container — securitywaittimes.com
- Knives, box cutters and loose razor blades, which may go in checked bags instead — securitywaittimes.com
- Lighter fluid, banned in both carry-on and checked bags — securitywaittimes.com
- Self-defense sprays over 4 ounces — securitywaittimes.com
- Marijuana, which remains federally illegal in either carry-on or checked bags — securitywaittimes.com
Quick checklist before you fly
- Pack liquids, gels and aerosols in containers of 3.4 oz / 100 ml or less inside one quart-size clear bag.
- Keep medications and baby formula separate and declare them if they exceed the liquids limit.
- Move spare power banks and lithium batteries into your carry-on — they cannot go in checked luggage.
- Check your specific airline's power-bank quantity and watt-hour limits before departure, since these vary by carrier.
- Keep shoes on for standard screening, but be ready to remove them if selected for secondary screening or if your ID isn't REAL ID-compliant.
Questions
- How big can liquid containers be in a carry-on bag?
- Each container must hold 3.4 ounces (100 ml) or less, and all of a passenger's containers must fit inside one quart-size, clear, zip-top bag.
- Do I still have to take my shoes off at airport security?
- Most travelers do not, after the Department of Homeland Security ended the general shoes-off requirement in July 2025, but officers can still require it for secondary screening or for passengers without REAL ID-compliant identification.
- Can I put a power bank in my checked luggage?
- No. Spare lithium-ion batteries and portable chargers must stay in carry-on bags because of fire-risk concerns in the cargo hold.
- How many power banks can I bring on a flight?
- TSA sets no fixed passenger count, but individual airlines have added their own caps — for example, American Airlines limits passengers to two devices under 100 watt-hours each starting May 1, 2026, while Southwest allows one.
- Are medications exempt from the 3-1-1 liquids rule?
- Yes, medications along with baby formula and breast milk can exceed the 3.4-ounce limit when declared to a security officer.
This piece was prepared with artificial intelligence and passed an automated source check before publication. If you see an error, ask for a correction. Request a correction or reply · How we make this
