Carry-On Rules Every Long-Haul Flyer Needs to Know in 2026

The 3-1-1 liquids rule still applies at nearly every US checkpoint in 2026, but some European and UK airports now allow up to 2 liters thanks to new CT scanners. Power banks must stay in your carry-on, never checked, and American and Delta now cap passengers at two per flight. Here's what's changed and what to pack around it.

TSA's 3-1-1 Rule Still Applies at US Checkpoints

Limit: 3.4 oz (100 ml) containers · Bag: one quart-size bag · Where: nearly all US airports

Despite talk of new scanners killing the rule, the TSA's 3-1-1 rule remains unchanged nationwide. Pack travel-size bottles in a clear quart bag.

New CT Scanners Let Some Travelers Skip the Bag Shuffle

Where: most lanes at ATL, LAX, JFK, ORD, DFW · Benefit: liquids and laptops can stay in your bag

Most checkpoints at major US hubs now use CT scanners that image liquids in 3D. The 3.4 oz limit still applies, but you often no longer need to pull items out for screening.

Some European and UK Airports Now Allow 2 Liters

Where: Dublin, Prague, Rome Fiumicino, Milan Linate, Heathrow, Gatwick, Edinburgh · Limit: up to 2L per container

Airports with new C3 scanners, tracked in this Euronews rollout report, now allow full-size bottles. Paris, Madrid, Athens, and Lisbon still enforce the old 100ml cap.

Power Banks Stay in Your Carry-On, Never Checked

Under 100Wh: unlimited, carry-on only · 101–160Wh: max 2, airline approval needed · Over 160Wh: banned

Per the FAA's lithium battery rules, spare batteries are prohibited in checked luggage entirely. If you gate-check your bag, remove the power bank first and keep it with you.

American and Delta Now Cap You at Two Power Banks

Effective: May 1, 2026 · Limit: 2 chargers, 100Wh or under · Rule: no charging from overhead bins

Both carriers now require power banks to stay visible and within reach, per Delta's battery policy. Check your airline's rules before packing multiple bricks.

Medically Necessary Liquids Get a Pass — If You Declare Them

Limit: "reasonable quantities" for your trip · Action: declare before screening · Covers: meds, saline, liquid nutrition

The TSA's medical liquids exemption sets no hard ounce cap, but the officer at the checkpoint makes the final call. Declare items before screening starts.

Compression Socks Are Worth Packing Past Four Hours

Risk window: flights 4+ hours · Evidence: reduces asymptomatic DVT · Cost: $15–30/pair

The CDC notes increased clot risk on trips of four-plus hours and says compression stockings may help some travelers. Ask your doctor if they suit your risk factors.

Time Your Melatonin to Beat Jet Lag

Dose: 0.5–3 mg · When: 30–60 min before target bedtime · Duration: 2–5 nights

Per the Sleep Foundation's jet lag guide, low-dose melatonin works best crossing five-plus time zones, paired with timed light exposure. Pack it in your carry-on in case bags are delayed.

TSA PreCheck or Global Entry Can Pay for Itself

Global Entry: $120 / 5 years · TSA PreCheck alone: ~$78 / 5 years · Includes: PreCheck access with Global Entry

Global Entry bundles expedited customs re-entry with TSA PreCheck for just $42 more than PreCheck alone. Many premium travel cards reimburse the fee.

People also ask

Can I bring a full-size water bottle through airport security in 2026?

Only at airports with new CT/C3 scanners, like Dublin, Rome, and Heathrow. Most US and many European airports, including Paris and Madrid, still cap liquids at 100ml/3.4oz, so travel-size bottles remain the safe default.

How many power banks can I bring on a flight?

There's no universal cap under 100Wh, but American and Delta now limit passengers to two chargers per flight as of May 2026. Batteries between 101–160Wh need airline approval; anything over 160Wh is banned outright.

Do all European airports allow 2 liters of liquid now?

No. Adoption is inconsistent and voluntary by country. Dublin, Prague, and several Italian hubs have upgraded, while Paris, Madrid, Athens, and Lisbon still enforce the 100ml rule.

What is the TSA liquid rule limit?

Containers must be 3.4 oz (100 ml) or smaller and fit inside one quart-size clear bag, per the TSA's official rule. Medications and baby formula are exempt if declared at screening.

Is Global Entry worth it for occasional international travelers?

Yes, for most people who fly abroad even once every year or two. At $120 for five years, it includes TSA PreCheck and cuts customs re-entry time, and the fee is often reimbursed by travel credit cards.

Facts checked against official TSA, FAA, CDC, CBP, and airline sources as of July 12, 2026. Rules vary by airport and change frequently, so confirm current policy before you fly.