Airport Security Rules in 2026: The 100ml Liquids Limit Is Back, and What You Still Can't Carry

Here is the short version for 2026: at most airports you should still pack as if the 100ml liquids limit applies, because it does. The new CT scanners were supposed to retire that rule, and at a handful of airports they briefly did — but the limit was reimposed at many of them in 2024, and the picture is now genuinely inconsistent from one airport to the next. This is what you can and cannot carry through security this year, and why the rule that "ended" is still following you around.

The liquids rule is still 100ml

The UK government's guidance is blunt: at most airports, you cannot take liquids in containers larger than 100ml through security. When a container is allowed, it must go in a single, transparent, resealable plastic bag that holds no more than a litre and measures approximately 20cm x 20cm — one bag per passenger. "Liquids" is broader than it sounds. It covers water and drinks, toiletries, sun cream, toothpaste, deodorant paste, mascara, lip gloss and anything with a soft, gel-like or spreadable texture.

There are exemptions above 100ml, but the list is narrow: essential medicines, medical equipment, dietary items and baby food or milk are allowed in larger quantities — up to around 2 litres — as is duty-free bought airside and sealed in a tamper-evident security bag. Expect to declare medicines and have them screened separately.

Why a rule that "ended" came back

The 100ml limit dates to August 2006, when British police disrupted a plot to smuggle liquid explosives disguised as soft drinks onto transatlantic flights from the UK to the United States and Canada. Within days, liquids were banned from cabins, and the ban was quickly standardised worldwide into the 100ml-in-a-clear-bag format we still use nearly twenty years later.

The exit was meant to be technology. As airports install advanced computed tomography (CT) scanners — 3D machines that read a bag's contents far more clearly than the old X-ray units — the liquids restriction can, in principle, be relaxed, and several airports lifted the cap to 2 litres. Then in June 2024 the UK reimposed the 100ml limit at airports that had rolled the scanners out, wanting the new machines performing consistently first. The result in 2026 is a patchwork: your outbound airport might wave through a 500ml bottle while your connecting or return airport confiscates it. Because the rollout is uneven, the only reliable move is to check your specific departure airport before you fly — and pack for 100ml regardless.

"3-1-1" and "100ml" are the same rule

If you have flown in the United States you will have heard the TSA's 3-1-1 rule. It is the same idea under a different label: 3.4 ounces (100ml) per container, 1 quart-sized clear zip-top bag, 1 bag per passenger. Europe, the UK and most of the world quote the metric "100ml" version instead. Because 3.4oz is simply 100ml rounded, a bottle that passes in London passes in Los Angeles. Don't be thrown by the two names — just pack to the smaller of any figures you see.

Laptops, tablets and phones

At a standard checkpoint, take laptops and other large electronics out of your bag and lay them in their own tray so the scanner gets a clean image; phones usually stay in. At airports running CT scanners you can often leave everything inside the bag, because the machine handles it. The two systems sit side by side even within a single terminal, so watch the lane signage and do what staff ask rather than assuming. Keep devices charged enough to switch on if requested — a completely dead laptop can be refused at some destinations.

Flying into Nepal — and onto Lukla

The same rules meet you at Kathmandu's Tribhuvan International Airport (TIA): 100ml liquids, power banks in your cabin bag, sharp items in the hold. The tighter squeeze is the domestic leg. Mountain flights — above all the short hop to Lukla for the Everest region — use small STOL aircraft with strict weight limits, often around 10kg of checked baggage plus about 5kg of cabin baggage per passenger, and excess is charged or offloaded. Keep power banks, camera batteries, documents and medicines in your cabin bag, and confirm the exact allowance with your carrier, since it varies by airline and season. If you trek with us, we plan your kit around these limits so nothing gets left on the tarmac.

Packing down to a single cabin bag makes every one of these checkpoints faster and cheaper — our guide to travelling carry-on only in 2026 shows how to fit a full trek wardrobe into one bag. And when you are ready to point all that at a mountain, browse our Nepal treks and tours; we will handle the permits, the domestic flights and the baggage maths.

Sources: UK Government (GOV.UK), hand luggage restrictions and liquids guidance; US Transportation Security Administration, the 3-1-1 liquids rule; Wikipedia, 2006 transatlantic aircraft plot. Rules vary by airport — always confirm with your departure airport before you fly.

Cover photo: 海风 张 via Pexels (Pexels License).