You may know the drill at airport security, but seemingly standard protocols can change significantly depending on where you are. “While many airport travel and security rules are fairly universal, there are still quite a few that vary by country and airport,” says travel expert and writer Jen Curnutt .
The Transportation Security Administration establishes airport security rules in the U.S., but “it’s a common misconception to assume TSA rules apply everywhere,” says Curnutt. And the rules aren’t always obvious — how to pack and store liquids famously trips up travelers around the globe. Whether to remove your shoes at security can be just as confusing abroad as it is at home.
Before traveling internationally, Curnutt recommends researching country-specific requirements for liquids, food, electronics, carry-ons and security-screening procedures. Here, she and other travel experts weigh in on these protocols and more.
Shoes
To remove your shoes in the security line or not to remove your shoes in the airport security line — that is the question. And it’s one without a singular answer.
The U.S. has long been known for applying the shoe-removal rule pretty strictly across the board in general security, but the Department of Homeland Security announced it would be ending this policy in 2025. That said, travelers may still be asked to remove their shoes at some U.S. airports. Once you leave the U.S., the rules and enforcement depend on where you are. Mexico and the Caribbean , for example, don’t have shoe removal rules at the airport, but you may still be asked to ditch your sneakers elsewhere, especially if they contain metal components.
Laptops and other electronics
The screening process for electronics like laptops and iPads can differ from airport to airport, and even from line to line. For example, U.S. airport security generally requires removing electronics from bags and cases, but TSA PreCheck passengers are exempt .
Vanessa Allen, director of marketing and communications at Cadence Travel , says it’s easy to get used to PreCheck privileges, but they don’t apply overseas. “It might be a rude awakening to discover that our domestic policies don't apply outside the U.S.,” she says.
Curnutt adds that newer baggage scanners in places like Singapore, Amsterdam and parts of the U.S. allow travelers to leave electronics packed away during security. In most places, a security agent will explain the rules when you step up to the belt. If you’re unsure, listen for instructions or ask for clarification.
Carry-on liquids
Many countries follow a 100-mL (or 3.4-ounce) liquid rule that limits travelers to containers of this size or less, carried in a clear quart- or liter-sized bag. But “some [countries] are stricter about the size and type of liquids allowed,” Curnutt explains. Airports across Europe and the U.K., for example, may enforce these rules more rigidly than in the U.S.
When the rules are applied strictly, “oversize containers may be confiscated, even if they’re only partially full,” says Curnutt, along with anything that doesn’t fit in an approved bag. To avoid sacrificing your toiletries, double-check the rules before you pack.
Metal detectors and body scanners
Airports across the globe use body scanners for security-screening purposes, but you’re more likely to pass through one at certain airports than others. It’s still fairly common to encounter standard metal detectors in the security line, and many airports have a mix of both. Travelers can sometimes choose to go through one or the other. In many countries, including the U.S. and U.K., you can legally opt out of the body scan and request a physical pat-down instead.
It’s also worth noting that there are two types of airport body scanners — backscatter X-ray scanners and millimeter wave scanners. Millimeter wave scanners are used throughout the U.S. and EU , though other scanner types may be used elsewhere depending on local regulations.
Carry-on baggage: weight and size
Curnutt says U.S. airlines tend to be more lenient with carry-on size and weight limits, while European and U.K.-based airlines tend to be stricter with enforcement.
“Bags are much more likely to be weighed or measured before boarding, particularly on European budget airlines,” she says. “In many cases, even slightly oversize or overweight bags can result in mandatory gate-checking fees or additional charges.”
Curnutt adds that you should double-check the personal item allowances for your flight as well, as some airlines enforce “very small size limits for backpacks, purses or computer bags.” While certain airlines may let you check an oversize bag for free at the gate, others will charge a fee.
Traveling with batteries
“Security requirements for power banks and batteries are often inconsistent between countries and airlines,” says Curnutt. “While most still prohibit lithium batteries and power banks from being packed in checked luggage,” she says some limits and standards differ. “Some airlines, particularly in Asia, are especially strict about visible battery labeling and capacity restrictions.”
Additionally, “some countries and airports may even ask travelers to power on laptops and cell phones during the screening process,” says Curnutt, “especially on routes with heightened security requirements.” Before gearing up for your flight, check the requirements for your departure country and airline to make sure you’re in the clear.
Traveling with food
Countries like the U.S., Australia, New Zealand and Japan are known for enforcing strict agricultural and customs regulations when it comes to food, according to Curnutt. “Travelers can face fines for failing to properly declare certain food items,” she says, even for seemingly harmless snacks. Fruit and packaged meats are common culprits, and many international airports employ “agricultural canines” trained to sniff out culinary contraband.
Common food items like yogurt, hummus, peanut butter and soft cheeses might also get a second glance at the airport, says Curnutt. “Most countries treat them as liquids for security purposes, but enforcement can vary significantly.” If you have any layovers during your journey, check the food rules for every stop. Bringing home edible souvenirs is possible, but you may need to transport them another way.
Duty-free purchases
Duty-free airport purchases can sometimes be an issue for travelers on multi-leg trips, says Curnutt. “A sealed duty-free bottle purchased after security in one country may still be confiscated during a layover if it doesn’t meet that airport’s screening requirements,” she says. For example, Curnutt says the U.K. is typically strict about re-screening duty-free liquids during connections.
If you’re traveling with a layover, leave your duty-free purchases for the last leg of your journey, so you can make sure they make it to your final destination.
Customs and border security protocols
Customs and border security is a separate process from standard airport security, and it can look fairly different depending on your departure airport. In most instances, you’ll pass through these checks upon arrival, but this isn’t always the case.
When flying out of most European airports, you’ll only pass through standard security checks, then visit U.S. Customs and Border Protection upon landing back in the U.S. However, if you fly from Ireland to the U.S. via the Dublin or Shannon airports, you’ll pass through “a U.S. border on Irish soil” before boarding your flight. Several major airports throughout Canada also have U.S. pre-clearance checks for U.S.-bound passengers.
Allen says navigating foreign security screening processes can feel confusing, with “so many quirky rules.” She recommends doing your research early and considering working with a travel adviser who specializes in the countries you’re traveling to and from.
