Liquids are the single most common reason something gets taken off you at airport security — and increasingly, the rules are not the same at both ends of your trip.
The US rule has not changed, despite a run of headlines saying it was about to. Parts of the UK and Europe genuinely have changed, but inconsistently, airport by airport. The result is a situation where the correct answer now depends on which terminal you are standing in.
Here is what actually applies, and how to pack so it does not matter.
1. The Short Answer
| United States | United Kingdom | |
|---|---|---|
| Container limit | 3.4oz / 100ml | 100ml at most airports; up to 2 litres at some |
| The bag | One quart-sized clear resealable bag | Transparent resealable, max ~1 litre, ~20cm × 20cm |
| Bags per person | One | One, where required |
| Must you remove it? | Often not, at CT-scanner airports | Depends on the airport |
| Medication & baby milk | Exempt, declare it | Exempt, declare it |
The one durable rule: pack to the strictest limit you will face on the whole trip — including the airport you connect through and the one you fly home from.
2. The US Rule: 3-1-1, Unchanged
The 3-1-1 rule is still the federal standard at every US checkpoint:
- 3 — containers of 3.4 ounces (100ml) or less
- 1 — all fitting in one quart-sized clear resealable bag
- 1 — one bag per passenger
Two details catch people out constantly:
It is the container size that counts, not the contents. A 200ml bottle with 50ml left in it fails. Security is judging the vessel, not the volume.
"Liquid" is a much wider category than it sounds. Section 5 covers this properly, but the short version is that anything spreadable or squeezable qualifies.
Why you heard the rule was ending
In July 2025, the Homeland Security Secretary said the liquids policy was under review and suggested permitted sizes might change. That produced a wave of coverage — and no actual change. Nothing about 3-1-1 has been altered. If you are flying within or into the US, pack to 100ml.
3. What Did Change in the US: The Scanners
The limit stayed. The experience improved.
CT scanners are now standard at major hubs including Atlanta, LAX, JFK, O'Hare and Dallas Fort Worth. They produce a 3D image detailed enough that staff can resolve what is in your bag without you unpacking it, which means at those checkpoints you often do not have to take your liquids bag or your laptop out at all.
This is a genuine time saver, and it is also a trap: getting waved through with your bag inside at JFK does not mean your 150ml sun cream was legal. It means it was not spotted, or the checkpoint was operating differently that day. The container limit still applies.
Keep the bag accessible regardless. Not every lane at every airport has the new machines.
4. The UK and Europe: It Depends on the Airport
This is where it gets genuinely messy, and where most guides online are wrong or out of date.
UK government guidance is explicit that there is no single national answer. Its own wording is that "the rules for carrying liquids in your hand luggage depend on the airport" — at most airports the 100ml container limit still applies, while some airports may allow containers holding up to 2 litres.
The same guidance notes that the clear-bag requirement — a single transparent resealable bag holding no more than a litre, roughly 20cm × 20cm — is also not universal any more. Some airports have dropped it; many have not.
The driver is the same CT/C3 scanner technology, rolled out unevenly. Airports that have completed installation and been approved can relax the limit. Airports mid-rollout cannot.
Which airports?
As of August 2026, several UK airports have been reported as operating a 2-litre limit — among them Heathrow, Gatwick, Edinburgh, Birmingham, Bristol, the Belfast airports and London City — while Manchester, Stansted, Luton and East Midlands have been reported as still enforcing 100ml.
Treat that list as a snapshot, not a rule. It has changed repeatedly and will change again as installations complete, and an airport can revert temporarily if a scanner goes down. Across the EU the picture is even less consistent.
Check your specific departure airport's own website in the week before you fly. That is the only source that is reliably current, and it takes about thirty seconds.
5. The Connecting-Flight Trap
This is the part that catches out experienced travellers, and it is worth its own section.
The limit that applies is the one at every checkpoint you pass through, not just the first.
Fly from Heathrow with a 500ml bottle of moisturiser under the 2-litre allowance, connect through an airport still on 100ml, and it gets taken off you there. The same applies coming home: your outbound airport's generous limit is irrelevant at the airport you return from.
Practical rule: pack to the strictest limit on your entire itinerary. Unless every airport on the trip is confirmed relaxed, that means 100ml. This is why the 100ml habit is still the right default even as the rules loosen — it is the only setting that works everywhere.
6. What Counts as a Liquid
The category is far broader than "things that pour." Officially it covers liquids, gels, aerosols, creams and pastes. In practice:
Things people are surprised by:
- Toothpaste
- Mascara and liquid foundation
- Peanut butter, jam, honey, hummus
- Yoghurt and soft cheese
- Sun cream and moisturiser
- Hair gel, wax and pomade
- Deodorant in gel or roll-on form
- Lip gloss and lip balm in pot form
- Snow globes — genuinely, a classic confiscation
The working test: if you could spread it, squeeze it or pour it, treat it as a liquid. The label is irrelevant.
What is not a liquid: solid deodorant sticks, shampoo and conditioner bars, solid perfume, lipstick, powder cosmetics, wet wipes, and toothpaste tablets.
7. Exemptions: Medication, Baby Milk, and Dietary Needs
Medically necessary liquids are exempt from both the 100ml limit and the quart-bag requirement. This is a real exemption, not an officer's discretion, and it is worth knowing precisely.
Covered: prescription and essential over-the-counter medication, breast milk, formula, toddler drinks, baby food and puree pouches, juice for babies, and liquids for documented dietary requirements. You do not need to be travelling with your child to carry breast milk.
How to use it properly:
- Declare at the start of screening, before your bags go on the belt. Not after.
- Take them out to be screened separately from everything else.
- Ice packs, freezer packs and gel packs to keep them cool are permitted, including when the milk itself is not present.
- Clear translucent bottles screen far better than pouches. Bottle liquid scanners often cannot read opaque plastic pouches, which means extra screening and delay.
- You can decline X-ray or opening of milk and food. Additional screening of you and the carer will follow instead.
- Keep medication in its original labelled packaging — it makes the conversation shorter, and it matters at customs at the other end.
Our baby travel packing guide covers feeding logistics on a flight in more detail.
8. The Powder Rule Almost Nobody Knows
In the US, powder-like substances over 12 ounces (350ml) must be put in a separate bin for X-ray, may need to be opened, and can be refused if the checkpoint cannot resolve what they are.
This catches:
- Protein powder
- Loose baby formula powder
- Ground coffee and spices — a common souvenir problem
- Large loose cosmetic powders
- Powdered supplements
Under 350ml, no special handling. Over it, put it somewhere you can reach without unpacking the bag, and consider the hold instead.
9. Building a Bag That Clears Every Checkpoint
The goal is a toiletry kit that never needs a decision at the airport.
Decant, don't buy miniatures. Refillable 100ml bottles cost less than travel-size products and let you take the products you actually use. Fill to about 80% — pressure changes make full bottles leak.
Label them. Unlabelled clear bottles occasionally attract a second look, and you will not remember which is conditioner.
Keep the bag permanently packed. A kit that lives ready — decanted bottles, solid bar, toothbrush, spare — removes the single biggest cause of last-minute liquid mistakes.
Pack it where you can reach it without opening the whole case, even at CT airports.
Buy the bulk items at the destination. Sun cream, shampoo and shower gel are heavy, cheap and available everywhere. There is little reason to fly them anywhere.
10. The Real Answer: Use Fewer Liquids
The most reliable way to pass a liquids check is to have almost nothing that qualifies.
- Shampoo and conditioner bars — no limit applies at all
- Solid deodorant — not a liquid
- Toothpaste tablets — increasingly good
- Solid perfume and lip balm sticks
- Powder sunscreen for top-ups, with a liquid base applied before you fly
- A bar of soap instead of shower gel
A traveller using mostly solids passes security with a nearly empty bag and never thinks about the rule again — and it works identically at a 100ml airport and a 2-litre one, which is the entire point.
For long flights, our long-haul checklist covers the rest of the cabin kit.
11. Let PackPilot Sort the List
The mistake almost always happens at home, not at the airport — a full-size bottle going into the bag because nobody thought about it.
PackPilot's assistant, Zippy, builds your toiletry list scaled to the trip and flags what needs to be travel-sized or decanted before you pack it, which is the only moment the decision is cheap. Items are assigned to bags, so what needs to be in the cabin is separated from what goes in the hold. Everything works fully offline.
Free, no subscription.
Download PackPilot on Google Play →
Rules described here were checked in August 2026 against TSA and UK government guidance. Aviation security rules change, airports vary, and individual officers have discretion. Always check your departure airport's current guidance before you fly.
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Frequently Asked Questions
Liquids, gels, aerosols, creams and pastes in your carry-on must be in containers of 3.4 ounces (100ml) or less, all of which must fit inside one quart-sized clear resealable bag, with one bag per passenger. The container size is what counts, not how much is left in it — a half-empty 200ml bottle still fails.
No. Despite headlines in 2025 suggesting the policy was under review, the 3-1-1 rule remains the standard at every US airport. What changed is the experience rather than the limit: CT scanners at major hubs mean you often no longer have to take the bag out of your luggage. The 100ml container limit itself is unchanged.
At some UK airports, yes — but not all of them, and this is the important part. UK government guidance states that at most airports the limit is still 100ml per container, while some airports allow containers holding up to 2 litres. The rule depends on the specific airport, so check the one you are flying from before you pack.
More than people expect. Anything spreadable, squeezable or pourable: toothpaste, peanut butter, yoghurt, mascara, liquid foundation, sun cream, hair gel, deodorant in stick-gel form, and soft cheese. The working test is whether you could spread or pour it. If yes, it goes in the bag regardless of what the label calls it.
No. Medically necessary liquids, including prescription medication, breast milk, formula and juice for babies, are allowed in quantities greater than 100ml and do not need to fit in the quart-sized bag. Declare them to the officer at the start of screening and take them out to be screened separately. Ice and gel packs to keep them cool are permitted too.
Powder-like substances over 12 ounces (350ml) must be placed in a separate bin for X-ray screening in the US, may need to be opened, and can be refused if they cannot be resolved at the checkpoint. This catches protein powder, loose baby formula, ground coffee and large cosmetic powders. Under that size, no special handling is needed.
Yes. Zippy builds your toiletry list scaled to trip length and flags the items that need to be travel-sized or decanted before you get to the airport, which is when the decision actually matters. It works fully offline, so your list is available at the terminal even with no signal.