The 100ml rule controls the amount of liquids and gels allowed in carry-on bags, limiting each item to a container of 100ml or less. Each liquid must be stored in a single container (no larger than 100ml) and put in a single resealable plastic bag when going through security. While the 100ml rule isn’t enforced everywhere, many countries, including those in the European Union, the US, and the UK , still apply it, although some airports have removed it entirely. Travelers should always check the specific rules of the airport or country they’re flying from to avoid any surprises at security.
Understanding the 100ml Rule
The airline industry is one of the most heavily regulated in the world, and rightly so. You’re flying people through the sky, over thousands of others, in a massive aircraft where even the smallest issue can have catastrophic consequences. One of the many security measures in place to keep things running as safely and smoothly as possible is the 100ml rule.
This regulation was introduced to limit the amount of liquids a passenger can bring on board to containers no larger than 100ml. All of these must fit into one zip-lock bag (the kind you see everyone scrambling for at the security line) and be separated from the rest of your hand luggage to go through the scanners on its own. If the security team finds that your liquids exceed the maximum allowance, they’ll have no choice but to confiscate them, so follow the rules, kids.
Understanding the 100ml rule: All liquids in hand luggage must be in containers of 100ml or less, and fit into a single resealable 1-litre plastic bag for security screening © Kiwi.com
The Reason Behind This Rule
You’ll often hear people complain about the 100ml rule. And sure, it can be annoying, but it was introduced back in 2006 for a very good reason. After an attempted terrorist plot at London Heathrow Airport , where individuals tried to bring liquid explosives through to attack some aircraft, the EU, the UK, the US, and many other countries introduced the 100ml rule to improve passenger safety . So, the next time you get cranky because your sunscreen ends up in the bin instead of your beach bag, remember, it’s all in the name of saving lives.
As time has gone on and airports have modernised, certain airports, particularly some in the UK, have scrapped the 100ml rule . This has been something of a confusing ordeal, as only some airports have the technology to scan liquids in hand luggage. For example, from July 2025, airports like Edinburgh and Birmingham have been allowing passengers to carry containers of up to two litres in their hand luggage. Others, like Gatwick and Liverpool, have no restrictions on the number of 100ml containers that can be brought through, and these can be left in a passenger’s bag. Meanwhile, Heathrow and Manchester are still following the traditional 100ml rules. That’s why doing your research beforehand is essential.
Does the 100ml Rule Have Any Exceptions?
The 100ml rule doesn’t apply to everything; some items get a pass. Here are the exceptions, provided that they meet the conditions listed below.
- The items are required for essential medical use.
- The items are required to feed an infant or a child.
- The items were purchased from an airport duty-free shop, are sealed, and include a visible receipt.
What’s Considered a Liquid or Gel
- Beauty items like makeup.
- Personal care products such as perfume and cologne.
- Any type of beverage, be it alcoholic or non alcoholic.
- Edible liquids like honey.
- Aerosol products, such as deodorants.
- Contact lenses.
- Thick creams or pastes, including dental care products.
- Gel-based items, such as body wash.
Is It the Container or the Contents That Matter?
You wouldn’t be the first to think that a big bottle with a little bit of liquid might be let off the hook. However, that’s not how the rule works. Regardless of how much liquid is inside, the container itself must not exceed 100ml; otherwise, the security staff will confiscate it.
Unfortunately, there’s no way for them to verify the exact amount of liquid in something like a half-full water bottle. If they were to let you through, who’s to know you won’t top it up with something you shouldn’t? They can’t, so don’t expect them to be lenient.
Where Should You Pack Your Liquids – Carry-on or Checked Bag?
You have two options for storing your liquids: either limit yourself to a few 100ml bottles and pack them in your hand luggage, or place them in your checked baggage.
Let’s go through the pros and cons of both methods.
Pros and Cons of Packing Liquids Into Your Carry-On
Pros
- They’re securely stored in a sealed bag, so if they leak, they’ll cause minimal damage.
- You have access to them whenever you want.
- If you’re carrying something that’s prohibited, at least you’ll waste minimal time at security, rather than having to return landside to remove it from your baggage.
Cons
- There’s a higher chance that something will be taken from you if you forget to double-check your bags.
- You’re restricted on how much liquid you can bring through.
- They take up extra space in your carry-on, which is already small enough.
Pros and Cons of Packing Liquids Into Your Checked Baggage
Pros
- You don’t have to follow the 100ml limit.
- One less thing to remove from your bag when you’re going through security.
- Because the inspection process for checked baggage is not as thorough, carrying liquids that way tends to be more straightforward.
Cons
- Leakages are more likely, especially when your bag is being thrown onto the plane, as the impact may cause containers to crack.
- You won’t be able to use that liquid until you reach your final destination.
| Feature | Carry-On Liquids | Checked Baggage Liquids |
|---|---|---|
| 100ml Limit Enforced | ✅ Yes | ❌ No |
| Access During Flight | ✅ Yes | ❌ No |
| Risk of Confiscation | ⚠️ High if non-compliant | ✅ Low |
| Leak Risk | ✅ Contained in sealed bag | ⚠️ Higher (due to rough handling) |
| Speed Through Security | ⚠️ Slower (need to remove for scan) | ✅ Faster |
| Ideal For | Essentials needed mid-flight (e.g., meds) | Larger containers, full-size toiletries |
Worried About Liquids at Security? Here’s What to Do
Go Through Your Bag the Night Before and Pack Your Liquids Ahead of Time
The night before your flight , have a quick look through your hand luggage to make sure you haven’t forgotten to remove anything that isn’t okay to bring. Then, place your liquids into your own resealable pouch (make sure it’s in-line with the guidelines) so you know exactly what you’ve packed, put it in your bag, and you’re good to go.
Pour Your Liquids Into Refillable Containers (And Label Them)
Go online and search for ‘TSA-approved travel bottles.’ You’ll find plenty available for purchase. This way, you’ll be able to pour a measured amount of your liquids into reusable containers that comply with airport regulations, so you won’t have to worry about them getting snatched. It’s also a good idea to label each one clearly to let the security staff know what’s inside to prevent them from asking questions.
Consider Solid Products
Security may think they’ve got you with the liquids, but they can’t do anything about solid products. Swap out your spray deodorant for a roll-on, or pack a shampoo bar, and be the smug one racing through the line while everyone else gets held up.
Follow the 100ml Rule, or Pay the Price
Like it or not, the 100ml rule is in place, and if you’re flying, you have to follow it. It can be confusing when the rules vary between countries, and even between airports. Always check the airline’s website for the latest guidance, and confirm the details with a few reliable sources, just to be safe. In case you can’t find any clear information, it’s best to stick to the 100ml rule to avoid any issues at security; you’ll thank yourself later.
Important Liquid Rules You Need to Know Before Flying
How many 100ML bottles can I take on my flight?
There’s no limit on how many 100ml bottles a passenger can bring on a flight, as long as they all fit into a resealable bag with a maximum capacity of 1 litre. The bag must be able to close comfortably, or it may not be accepted at security.
What if I don’t comply with the 100ml liquid limit?
Any passenger carrying a container larger than 100ml through an airport where it’s against the rules will likely have the item confiscated. There are some exceptions, such as medications and baby food, but always check in advance rather than assume.
Is it okay to separate my liquids into multiple bags?
No, all of an individual’s liquids must fit into a single resealable bag with a maximum capacity of one liter. If your items can’t fit into that one bag, you’ll need to leave some behind.
Am I allowed to bring a reusable water bottle through security?
Yes, passengers are allowed to bring reusable water bottles through security, but they have to be empty when going through the scanners. After you reach airside, you can refill them at any available water refill station.
