A one-litre capacity does not translate into a one-litre capacity for all toiletries in your bag. Typically a one-litre capacity will hold about 6 to 8 mini bottles (or containers) due to the physical dimensions of the containers, and the need for the bag to actually seal correctly around your toiletries! Thus, the best way to begin filling your bag is to determine which liquids are going to be left off the fill list before you put anything inside the bag. The ‘carry on liquids restriction’ placed by the UK is very clear about the most important points that most people will miss; the container for liquid must have a volume of 100ml, regardless of how ‘full’ it is. The limitation applies to the entire bag!
That means that, if you have a nearly empty bottle of toothpaste, you are limited to that size container regardless of how much toothpaste is left in the bottle; the same goes for a half-empty tube of face cream. Both of these products have their total volume equal to the printed volume of their containers.
The Container Capacity Rule: Why Security Screeners Confiscate Half-Empty Bottles
When going through screening, half-empty bottles will be taken from you because the measure for regulated liquids is based on the capacity of the bottle rather than how much liquid is left in the bottle. The civil aviation authority in Brazil specifically states that: “No person shall be permitted to take onto an aircraft any liquid in a container holding more than 100ml” – this applies equally if the container is partially full. The same statement holds true for airports in the UK as per the guidance provided by Manchester Airport.
Both Brazil and the UK provide an official source for guidance on maximum container capacity. When considering what you can bring with you on your travels, check the airport you are flying to before starting to pack your bags. Additionally, the regulation regarding maximum container capacity follows you from the checkpoint as opposed to you taking it along with your baggage or belongings. The various authorities responsible for configuring the liquid limits do not grant liquid limits based upon the nationality of the passenger. Thus, every passenger waiting in the same lane is held to the same rule, regardless of which passport they are presenting to the agent at the checkpoint.
The rationale behind writing a liquid maximum limit based upon container size only is logical. It is simple to obtain the size of the container based upon the print that is present on it and it can be easily checked while in process on the belt. Whereas for opaque containers it is not possible to judge how much liquid is in them; therefore, there is no way to resolve disputes based upon the quantity of liquid in opaque containers. Thus, the actual enforceable number that can be determined is the capacity printed or moulded on the outside of the container. Canada’s screening authority writes that number two ways, 100 ml or 100 g, which matters for anything sold by weight. Canadian screening authorities provide a maximum limit of 100ml or 100g and under Canadian regulations, if an opaque container contains 100ml of shampoo, the shampoo will be weighed or measured and this will be recorded.
What actually counts as a liquid
The “container rule” is the easy half of the designation. The half that people empty their bags for is deciding what is considered a “liquid.”
Instead of identifying an object by name to determine its liquid status, consider how the object behaves. Canada has an established ‘test’ for food; anything that is a solid at room temperature qualifies, which explains why freezing will not change the classification of a solid food. For most items, refer to the long list of items.
What counts as a liquid by the UK includes creams, lotions, and oils, perfumes, mascara and lip gloss. The European Commission has defined liquids to include gels, aerosols and pastes, so the list will also include liquid/solid mixtures. In addition, Canada’s list extends to included jam, yogurt, mashed potato, peanut butter and gel blush. The former spokesman for the United States Transportation Security Administration, Lisa Farbstein, provided an informal way to determine whether something is considered a liquid to the Akre of Afar; basically, if something can be spilled, sprayed, spread, pumped or poured, treat it as a liquid.
The table below lists examples of items that are difficult for people to determine if they are liquids; therefore, it is a useful reference.
| What you are holding | Treated as a liquid? | What settles it |
|---|---|---|
| Toothpaste, shower gel, shaving foam | Yes | Pastes, gels and pressurised foams are named on the UK and Canadian lists |
| Mascara, liquid eyeliner, gel blush, lip gloss | Yes | Liquid- and gel-based cosmetics, named explicitly by both |
| Peanut butter, jam, yogurt, mashed potato | Yes | Spreadable food sits on Canada’s gel list |
| Bar soap, powder, solid stick deodorant | Not named on any of these lists | Absence from the list, rather than a rule saying solids are fine |
| Anything you froze to get around the rule | Yes, in the UK and Canada | Both refuse frozen liquids in hand baggage outright |
| A 150 g tube of something spreadable | Yes, in Canada | The limit there is written as 100 ml or 100 g |
The last column is the most helpful. Two of the rows have an explicit rule associated with them (so can provide clear guidance) and two of the rows use examples that are omitted from the list (this is often the source of arguments between security personnel and passenger’s).
The final determination is made at the security checkpoint; there is no consideration at the kitchen table. On r/HerOneBag, the original poster described their experience at security in the UK and the Netherlands as a “surprise” since the TSA representative took their solid stick deodorant and told them it was considered a liquid. A second traveller who commented on this thread described a similar experience at an airport in Berlin, stating that any substance that is liquid at room temperature would likely be considered a liquid.
The two examples cited in this paragraph are two individual, concrete examples from the years 2024 and earlier and should not be interpreted as a representative sample of the frequency with which this occurs, but rather represent an actual seam of discontinuity in the way that the items were classified between the different airports. Solid stick deodorants are not classified as liquids in the charts provided above, nor do they fall under the exemption categories, therefore they are subject to the discretion of the TSA employee working at that particular checkpoint.
This thread also contains a long-standing myth circulating through various travel discussion forums that states that if an item has a millilitre measurement on the label, it is a liquid, and if it has a gram measurement, it is a solid. Specifically, since both Canada and the US have set their limits on the number of ml (100 ml or 100 g), that myth fails dangerously for travellers because part of the rationale behind having ml and g values on the same piece of luggage is that the tables listed above can show how this myth can impact the area where a traveller’s luggage was located.
When you find an item that truly appears to be on the line, please look it up in the TSA’s searchable database rather than arguing with the TSA at the checkpoint. The TSA has published a searchable list of thousands of items by item number and text, and it specifically states that “Even permitted items may be restricted by the TSA if they alarm during screening, or if a TSA officer has another reason for concern.” This is the only honest boundary that applies to everything listed above; the published rule indicates what needs to occur, while the TSA agent before you determines what actually takes place.
The issue of how many compliant bottle can either fit into a single bag or how many can potentially fit into an individual bag is an independent situation, as it is primarily based upon geometric principles rather than regulatory restrictions.
The One-Liter Pouch Math: Packing Geometry, Bag Dimensions, and Decanting Ratios
Two different numbers define both the stated capacity of the bag and the usable capacity of the bag. This is already stated in the rules. In Brazil, the regulations require that the bottles fit loosely in the closed bag. The UK uses the wording: “contents must fit comfortably inside the bag to be sealed” and specifies that the bag may not be tied at the top. TSA’s guidelines for miniature spirits are also based on whether or not they can “comfortably fit” in a single quart-sized bag. When it comes to packing, the three different authorities have a similar perspective: When the bag is filled to its theoretical capacity, it is not compliant.
In addition, two additional factors contribute to the differences. The bottle takes up more space than it holds due to the fact that the walls, shoulder and cap are not part of the product. Furthermore, the bag is flat and rectangular, whereas in Canada it is approximately 20cm x 17.5cm (1 litre), while the UK has it as approximately 20cm x 20cm (1 litre). The bags are an outline; they aren’t volumes.
Finally, the packaging unit itself (the quart) is not just an American unit of measurement; it costs Americans valuable space when packing.
| The bag | Stated size | What that actually means |
|---|---|---|
| US quart bag | 1 US quart, about 0.95 litres | The smallest of the standard bags, by roughly 5% |
| UK, EU and Canada 1-litre bag | 1 litre | Flat, about 20 x 20 cm (UK) or 20 x 17.5 cm (Canada) |
| What you can genuinely fill | Less than either | The seal has to close with the bottles sitting loosely inside |
A quart does not equal a litre. Consequently, on a round trip, it is the smaller unit that dictates how you pack. If you fill your bags to the litre for a European departure, you may find yourself exceeding the limit during customs when returning through a US checkpoint.
The bag you bought may not be the bag you think
Retail toiletry pouches claimed to be compliant are not necessarily compliant. On the Rick Steves travel forum, the traveller who started this thread in November 2023 indicated that “many of the clear bags designed for carry-on luggage exceed a quart size,” and that several websites list bags as quart-sized when they are “almost 2 quarts.” When this issue was discussed, many regular contributors were of the same opinion; do not purchase an overpriced special toiletry bag, simply use a quart or litre freezer bag from a grocery store. Another contributor explained what the staff stated they were looking for at Heathrow, as of the time of the thread; “strange shapes and designs that prevent you from seeing inside,” and any bag that exceeded its stated capacity.
The aforementioned thread is indicative of the situation in late 2023. However, the UK has changed a lot since then. Heathrow doesn’t ask for a bag at all, and the current position of the UK Government is that you do not need to have a separate clear bag for every airport. By contrast, the fundamental test has not changed, and you can replicate it at home. Take your entire kit, seal the bag, lay flat and gently press down; if the zip becomes strained or cannot lay flat, you have “exceeded the fit comfortably” requirement as outlined in the rules and need to remove an item from the bag now rather than wait for security.
There is one particular piece of information provided by Manchester Airport with respect to their security policies that does not get enough attention because it negates a lot of detailed packing. The airport’s last updated their security guidance in April 2026 and this has a rule stating that any container you bring along with you must have printed capacity on it, travel sets without printed capacity will not be permitted through security and that it won’t be acceptable for handwritten or stickered capacity. This is just an extension to the Container Capacity Rule: without a printed number to view, there’s nothing to read; therefore, an unreadable bottle fails for the same reason that a bottle that exceeds the allowable size fails also.
This highlights what is really the lever. The majority of people have way more product than what they will use when they are travelling, and it’s stored in their bathroom cabinets. An example of this is calculating the approximate amount of something you consume during a week and multiplying that number by the duration of your trip to determine how much you will need instead of relying on the largest compliant bottle available.
In the same thread on Reddit (HerOneBag), another traveller indicated that she decanted her facial product into contact lens cases that she estimated were enough for at least five days’ worth of product. That’s the basis for this guide’s rule of thumb – two amounts; the amount you use and the length of the trip. Please be sure to review the Container Capacity Rule prior to assuming that you can use contact lens cases to get through a strict checkpoint.
The question of what to do with liquids is separate from the decision to have a checked bag on this trip. This guide focuses on the choices between carrying on or checking bags, not on how to handle liquids if you can’t get them into your checked bag.
The Solid-Swap Strategy: Eliminating Bulky Liquids to Reclaim Pouch Space
Every gram moved from the liquid container makes it possible to have an item that does not have a corresponding solid equivalent. For example, prescription skincare, liquid foundation, contact lens solution, and specific fragrances, all of which cannot be replaced by a solid equivalent, fall into this category. The large items, such as shampoo, conditioner, soap, etc., have a few solids equivalencies, and they are also the largest items in the bag. This is the asymmetry that is the basis of the entire strategy; convert the heavy, replaceable items to allow for the irreplaceable items to fit.
The mechanism continues to work for you as discussed in the prior section. The lists of liquids, aerosols and gels published by the UK, the European Commission and Canada contain no mention of bars, sticks or powders, which means they are not restricted by the 100 ml ceiling and therefore do not compete for the same space in the bag. Canada specifies the principle underlying this for food. An item is classified as a solid if it is a solid at room temperature. Therefore, a shampoo bar has the same classification when in a warm bathroom.
| Liquid you are carrying | Solid equivalent | The honest trade-off |
|---|---|---|
| Shampoo and conditioner | Bars | Needs a tin or the bar softens and sticks to everything |
| Shower gel or body wash | Bar soap | Nothing lost, other than habit |
| Toothpaste | Tablets or powder | Texture takes a few days to get used to |
| Roll-on or gel deodorant | Solid stick | The one most often argued about at European checkpoints |
| Liquid foundation, serums, prescription creams | None that works | Keep these; they are what the reclaimed space is for |
The table’s last row is the purpose of this exercise. The swaps are a means to an end; they allow you to no longer have to choose between taking your sunscreen and your medication.
Also, please be aware of two cautionary notes, since many people are misled by the internet. First,just because it is solid, does not mean it is not visible: all powders attract their own visibility. Secondly, the TSA requires all powder-like substances greater than 350 ml or 12 oz to be placed in a separate bin, and Heathrow advises that no powders greater than 350 g or 350 ml are allowed in the cabin of flights to the United States.
Being solid doesn’t mean it’s guaranteed to be accepted. The two examples of solid stick deodorant mentioned on the r/HerOneBag thread, as well as two travelers sharing experiences with their liquid stick deodorants while using the border controls of the United Kingdom, Netherlands, and Germany. A previous British Airways flight attendant also said in a comment that they have never experienced any issues taking solid stick deodorants or moisturising bars while travelling. This tells us that both these statements are correct, although it does indicate that the swap has been successful in almost all cases and not as a certainty, therefore if a traveller were to test it out, the most costly version would be a poor choice for testing.
That said, there are many other items that should not be swapped or shrunk down. These items have separate, distinct policies that apply to them.
Medical and Dietary Exemptions: How to Carry Necessary Liquids Outside the Pouch
Any liquids that are medically required including formula, breast milk and toddler food (that are more than 100ml) are not packed into a quart-sized bag. An authority who has mentioned all of these in very close proximity to each other has also confirmed this.
The TSA specifically treats formula, breast milk and toddler food (that are over 100ml) as medically required and states they do not have to be contained within a quart-sized bag. The European Commission allows you to take essential medicines (including formula, baby food, etc.) that are over 100ml for your trip. The UK allows liquids up to 2 litres in size through security at all UK airports for medical, special dietary purposes, or baby food and milk. Brazil also permits you to carry any liquid medication that is prescribed to you, for as much as you may need for the entire duration of your flight including layovers.
All of these positions were confirmed with the above dates on 20 September 2026.
What differs within these policies is the type of documentation that is required and how they will affect how you go about taking your trip.
In terms of the documentation required to carry necessary medications, Manchester requires a letter from your doctor, a copy of your prescription, or a label from the prescription bottle for medications over 100ml. There are no requirements regarding documentation for tablets or medications that are 100ml or less in size. You may only be required to provide a prescription or doctor’s letter at Heathrow if you are trying to carry liquids over 2 litres. In Canada, they state you do not need to provide any documentation; however, they also advise you to carry it because it may make the process easier for you. Brazil requires you to provide either a hard copy or a digital copy of your prescription in order for the exception to apply. Therefore, if you have the requisite paperwork and are not sure about what your airport requires, it is best to check with them before you travel.
When it comes to procedure there is one common consideration, the need to segregate and declare items before placing them in the screening machine as opposed to after the officer discovers an item. The TSA wants you to let the officer know when you get screened and to take out any items that will be screened separately. The TSA allows you to request that the items you want screened never go through liquid screening if you prefer not to X-ray or open the item; you can ask for additional screening instead.
The rules for Brazil extend that right named according to a directive issued in 2015 which allows you to ask a civil aviation security agent to conduct a separate inspection of medicines without the use of X-ray or a metal detector. To do this you must hand over the medicines separately and may be asked to hold, present and repack the medicines so they do not become contaminated.
Heathrow has at least two basic limits most people overlook. First, breast milk may only be in liquid form, not frozen, it must be placed into a clear container, and your breast milk cannot be stored in a metal or insulated container. Secondly, an exemption is not guaranteed clearance, you must resolve with the officer if something alarms.
The most common way people lose their duty-free exemption is on a technicality rather than when they’re at the cash register. Canada’s officials have the clearest rules on this subject. Purchases must be placed into an official, sealed security bag with an itemised receipt. If a retailer did not use the correct bag, if the purchaser has lost the receipt, if they opened the bag themselves, or if greater than 48 hours have passed since the date of purchase, Canada can ask for the return of these goods.
In addition, the same authority advises that duty-free liquids “may be intercepted” if the purchaser goes through pre-board screening at a connecting airport in another country, or if they pass through multiple airports over a two-day time frame. In fact, the window of opportunity is even tighter in Manchester, with a 24-hour window. Therefore, the only remaining rule in common is the most restrictive, i.e. purchase all duty free liquids on the last leg of travel, keep the bag sealed until you reach home, and if you purchase anything prior to making a connection, consider that item to be a potential risk.
None of the above exemptions changes the single factor governing what you pack — the specific checkpoint that you are going to stand in at the end of your journey.
The 3D Scanner Patchwork: Why Connecting Flights Still Demand the 100 ml Standard
Some airports have stopped enforcing the 100 ml rule; however, most have not. This rule is determined based on which specific gate you are passing through rather than on an airport-wide or country-wide basis. For instance, passengers traveling through Heathrow may carry an unlimited amount of liquid containers (up to 2 liters in volume) within their cabin baggage through Terminals 2, 3, 4 and 5 of the airport, as per Heathrow’s guidance. Passengers travelling from Manchester Airport still cannot travel with liquid containers exceeding 100 ml in volume. This inconsistency is not transitional. As of September 20, 2026, it is evident that there are still currently vastly differing policies across the UK.
Frankfurt illustrates how granular the differences can be between airports in Europe. The security information section of the Frankfurt Airport website indicates that CT scanners are being deployed at many of the Terminal 1 security checkpoints and all of the security checkpoints at Terminal 3 and therefore allows for up to 2 litre liquid container limits for passengers using these terminals without needing the 1 litre transparent bag. However, the security page also lists locations throughout the airport still requiring the old regulations to apply (e.g., Gates C1, C2, C4 & C6, specific designated security checkpoints, most likely special checkpoints and connection points for transiting passengers), and as such, for these locations the old regulations still apply requiring all liquid containers (including gels and creams) over 100 ml in volume must be packed in a 1 litre transparent bag. Thus, according to the security page on the Frankfurt Airport website, it is highly recommended that you confirm your departure gate prior to undertaking any packing activities. In this case, these details provide the most succinct explanation of the problem.
The following summaries are based solely on the official guideline provided by each respective airport and National authority on September 20, 2026, and represent a review of their respective published information; none of the summaries reviewed provide any indication as to what will occur on any given day moving forward.
| Where you are departing | Published container limit | What the relaxation does not cover |
|---|---|---|
| Heathrow (T2, T3, T4, T5) | Up to 2 litres, no bag needed | Heathrow warns that many other airports still apply 100 ml on your return |
| Frankfurt (most T1, all T3) | Up to 2 litres, no bag needed | Concourse C gates and transfer checkpoints remain at 100 ml in a 1-litre bag |
| Manchester | 100 ml, no bag required | The bag is gone, the container limit is not |
| Any US airport | 100 ml in one quart bag | Applies on arrival too, when you re-clear for a domestic connection |
| Dubai, Abu Dhabi | 100 ml | Standard limit at two of the largest connecting hubs outside Europe |
Each entry in that table contains a departure rule and is a trap because generous airports create the risk of granting the freedom of departure and then taking it back when the departure continues.
Heathrow even states that travellers will be under different rules when they travel back to their home airport than when they departed from Heathrow. The UK government writes the same kind of guidance and tells travellers to check the airport from which they will depart, as well as any airports they will pass through, when they return. Brazil’s aviation authority has passed the responsibility of informing connecting passengers on other routes about whether they can keep their luggage to the airline.
There is also a myth that should be cleared up. In July of 2025, a US Department of Homeland Security official suggested that container sizes would be part of the agency’s future rule announcements; this rumour has been repeated continuously since then. On 20 September of 2026, the TSA has not changed the published rule regarding container sizes; each container is limited to no more than three-and-a-half ounces (100 mL) placed within a ziplock-style bag that holds one quart. Where CT scans have been deployed throughout airport security in the US is with regard to whether or not they require travellers to remove their bags from their luggage but not in terms of what can be in the bags. Rumours have defined container size by the basis of a potential announcement.
There is only one rule that is universal.
Security-compliant toiletry packing checklist
Make one trip around the complete itinerary once before the actual trip.
Determine the most stringent checkpoint you’ll go through on your trip. Include all the airports where you’ll pass through security, including your return flight and any stops where you’ll exit the secure area. If any of these airports has a 100 ml restriction, then you must adhere to that restriction for your entire trip.
Step 2: Sort items based upon how they are used, as opposed to what the item is labelled. For example, all things that are sprayed or squeezed out of a container, such as toothpaste and mascara, would be classified as liquids. All items that maintain their shape and form at room temperature would be classified as non-liquids.
Step 3: Change liquids to solids. You can easily do this by switching shampoo, conditioner, soap, deodorant, and toothpaste for their solid equivalents. You should still retain the container (tin) for the solid versions of these items.
Step 4: Inspect all containers for a marked amount. They should not be marked, and they should not have stickers. Airports will refuse to accept unmarked decant bottles.
Step 5: Size based on the length of trip. Your sizing for your liquids should be based upon using the correct volume for the length of time you will be at your destination multiplied by the number of weeks you are travelling, not based on the largest bottle you currently own that meets the requirements.
Step 6: Physically set aside exemptions, such as medication, baby milk/formula and baby food, from the rest of your bag. Keep all items easy to access, and provide proof (such as a prescription or letter from your physician) for anything over 100 ml.
Step 7 – After filling your bag, make sure you seal the bag and store it flat. If you’re having trouble with the zipper, you may want to take some items out now.
Step 8 – When traveling with liquids that are duty-free, you should wait until the last leg of your trip to purchase them. If you purchase your liquids prior to your final destination, you should expect that you will lose them at an airport connection, and you will need to make a decision whether you can live with the loss.
The check that saves you the headache
Your limit for packing is determined not just by the airport that you’re departing from, but by the strictest limit of all the airports in your itinerary including your last stop, the trip home. Therefore, before you start to pack, you should make a list of all the checkpoints you’ll pass on your way to your destination and find out what’s currently being specified at each checkpoint by looking them up on the websites of those airports. It’s important to note that many airports within the same country have different responses for packing limits which may differ in terms of gate numbers or terminals. If you have accurate information for your departure airport and all the subsequent airports on your itinerary, then everything else is simply recordkeeping. If you do not have accurate information, the most common consequence is not that you will lose the shampoo, but rather that you will spend a significant amount of time repacking your luggage while others are moving through the line in front of you.
Frequently asked questions
What actually happens to liquids that do not clear security?
Canada’s Screening Authority presents three alternatives for items that cannot be carried aboard an aircraft; they may be surrendered at the checkpoint, transferred to the checked luggage compartment if time allows, or shipped via either mail or courier. Frankfurt also offers options to place declined items into a secured bag with redemption tags provided at the time of their return.
Do I still have to take the liquids bag out of my luggage?
The Airport Checkpoint role varies from one airport to another; for example, while passengers travelling through Heathrow, Frankfurt’s Scan Lanes; and Manchester, can keep liquids within the bag, those “in the know” know that the guidance issued from the European Commission and from Canada requires that all liquids and gels be placed into a clear plastic container prior to passing through security at all airports except for the specific mentioned here.
Are powders restricted in the same way?
Each country has its own regulations. TSA requires that powdered products weighing more than 350 ml or 12 ounces be screened separately in a container, whereas Heathrow does not allow for the transport of powder products greater than 350 grams or 350 ml through the cabin of a plane heading to the USA.
Travelling with children, do we get a bag each?
UK, Canada and Brazil publish their specified limits for the permitted amounts of items each passenger can carry. When travelling with someone under 2 years old, you will still consider them as a “passenger” regarding allowable limit and check-in baggage. No country published a restriction on what luggage to put items in. For example, one traveller wrote that when he attempted to split two bags between two separate hand-luggage pieces, he was refused. Therefore, ensure bags are kept segregated.
