Home / Airport Liquid Rules in the UK vs. US: What’s Different?
When you travel these days, there’s one thing you can’t escape: the liquid rules at airport security. Whether you’re flying out of London or New York, you’ll have to pull out those tiny bottles of shampoo, lotion, or sanitiser. You’ll stuff them into a little plastic bag and hope security doesn’t stop you. It feels normal now. But how did these rules even start? And are they the same in the UK and the US?
Did you know that the rules regarding liquids vary from place to place? Even between two big countries like the United Kingdom and the United States, there are small but significant differences you should know about.
If you are flying from the UK, here’s what you need to know:
But things are starting to change in the UK! Some airports have acquired new CT scanners. These are advanced machines that can scan your bags without requiring you to remove any items from them. At these airports, you can leave liquids inside your hand luggage.
Still, even with these new scanners, most places keep the 100ml limit for now.
Flying from the US? The basic idea is the same, but there are a few little twists.
Here’s what happens:
Additionally, major US airports, such as Atlanta or LAX, have also begun using CT scanners at security lanes. In some cases, you don’t have to pull out your liquids anymore. However, and this is important, the 3.4oz (100ml) size rule remains in effect, even with the new technology.
One small twist: The TSA (Transportation Security Administration) also has extra checks for “powder-like substances” if you’re flying into the US from another country. So, not just liquids, but powders too!
To make it easier:
| Rule | United Kingdom | United States |
| Limit per container | 100ml (3.4oz) | 100ml (3.4oz) |
| Bag size | 1 litre clear bag (20×20 cm) | Quart-sized clear bag |
| Bag requirement | Liquids must be inside and taken out | Liquids must be inside and taken out |
| Bag Type | Clear, resealable plastic bag | Clear, quart-sized plastic bag |
| Items Must Fit Comfortably? | Yes | Yes |
| Must Remove at Security? | Yes | Yes |
The degree to which the rules are enforced also differs slightly between the UK and the US.
In the UK, airport staff are usually strict but flexible. If your bottle is exactly 100ml, it’s fine. Even if your container is slightly larger but contains less liquid, it may still be allowed if you can prove the amount.
In the US, the TSA is much stricter. They care more about the size of the container, not how much liquid is inside. If the container says 120ml (4oz) but only has a little left in it, TSA will throw it away anyway. The bottle itself must be 3.4oz or less, regardless of the contents.
So, if you’re flying through the US, it’s best not to try to argue or explain; just stick to the rules.
Both the UK and the US permit exceptions for certain essential liquids.
You can carry more than 100ml if it is:
However, how these exemptions are handled can feel a little different.
Both countries take these exemptions seriously, but TSA in the US is usually more hands-on and might take longer.
Buying large bottles of alcohol or perfume after passing security? That’s called duty-free shopping.
In the US, if you are arriving from another country, TSA has extra checks for liquids, powders and gels. Powder-like substances exceeding 12 ounces (approximately 350ml) may require additional screening at security checkpoints. This rule is not yet common in the UK.
First, a brief bit of history to clarify everything. In 2006, a serious terrorist plot was stopped at London Heathrow Airport. The plan was to smuggle liquid explosives onto planes using normal-looking drink bottles.
As a result, airports worldwide rushed to implement new rules.
Since then, we have had the famous “100ml rule.”
At most airports around the world, you are not allowed to carry big bottles of liquids in your hand luggage. You can only carry small bottles, each no bigger than 100 millilitres (that’s about 3.4 ounces if you’re thinking American-style).
Liquids mean a lot of things:
And here’s the extra rule: All your tiny bottles must fit inside one small clear plastic bag that closes properly.
Yes, CT scanners are being installed at airports in both countries. However, it is essential to note that the liquid size rules (100ml/3.4oz) still apply almost everywhere.
Airports like London City and Teesside have begun allowing passengers to carry liquids inside their bags through security. Bigger airports like Heathrow are still catching up.
CT scanners are in use at airports such as Atlanta, Chicago, and Los Angeles. However, liquids must still adhere to the 3.4oz rule, regardless of the circumstances.
When you pack your bag for a flight, it’s easy to think the rules are the same everywhere. But slight differences between the UK and the US can trip you up if you’re not careful.
Remember, in both countries:
Always check the latest rules before you travel, as airport policies can change rapidly, sometimes even overnight. Flying can sometimes seem stressful, but following these simple guidelines can help make your flight run more smoothly. Knowing the fundamental differences can save you time, stress, and your favourite bottle of perfume.
No. Airports allow passengers to carry solid items, such as snacks, books, and clothes, without restrictions. However, they treat creamy or semi-liquid foods, such as yoghurt or peanut butter, as liquids, so you must follow the 100ml/3.4oz rule in both the UK and the US.
You can carry frozen liquids, such as ice packs, through security if they remain completely frozen solid during screening. If the ice packs melt or become slushy, security officers will treat them as liquids; therefore, you must follow the 100ml/3.4oz rule in both countries.
Yes. Liquid restrictions apply at all airports, regardless of size, in both the UK and the US. Smaller airports may have shorter security lines, but they adhere to the same liquid limits as major hubs like Heathrow or JFK.
In most cases, security officers will ask you to dispose of it. They will not usually let you go back to check it into your luggage unless you have extra time before your flight. This applies in both the UK and the US, though US airports tend to be stricter.
No. You are allowed only one clear plastic bag per person in both the United Kingdom and the United States. If your items don’t fit into one bag, you will need to leave some items behind or move them to your checked luggage.
In both the UK and the US, it is your responsibility to pack and present your liquids correctly. If you forget, you might be asked to step aside, repack your bag, or face delays at the security checkpoint.
