Airport Security & Carry-On Rules Explained (2026 Guide)
What you can and cannot bring through airport security — explained clearly for domestic and international travel.
Every year, millions of travelers face confusion, delays, and confiscated items at airport security checkpoints. The rules seem to change constantly, vary by country, and are often explained in confusing legal language.
This guide cuts through the confusion with clear, practical explanations of what you can and cannot bring through airport security in 2026. Whether you're flying domestically or internationally, this reference will help you pack correctly and pass through security smoothly.
Why Security Rules Confuse Travelers
- Rules vary by country: What's allowed in the US may be prohibited in Europe or Asia
- Enforcement differs: Some airports are stricter than others, even within the same country
- Regulations change: New threats lead to new restrictions, sometimes with little notice
- Exceptions exist: Medical items, baby formula, and duty-free purchases have special rules
- Language barriers: Official rules are often written in legal or technical language
Why This Guide Is Reliable
✓ Updated Regularly
We review and update this guide every quarter to reflect current regulations
✓ Multiple Sources
Information verified against TSA, IATA, and international aviation authorities
✓ Real-World Focus
Based on actual enforcement, not just written rules
✓ Global Coverage
Covers US, Europe, Asia, and other major travel regions
This guide focuses on carry-on baggage security rules — what you can bring through the security checkpoint and into the aircraft cabin. For information about baggage size and weight limits, see our Airline Baggage Size & Weight Guide.
What Airport Security Actually Controls
Airport security checkpoints exist to prevent dangerous items from entering aircraft cabins. Security officers screen for four main categories of items:
Liquids, Gels & Aerosols
The most commonly confiscated items. Includes water, shampoo, toothpaste, sunscreen, and any substance that can flow or spread.
Rule: 3.4 oz (100ml) maximum per container in most countries
Electronics & Batteries
Laptops, tablets, power banks, and devices with lithium batteries require special screening and have capacity limits.
Rule: Must be removed for screening; lithium batteries limited to 100Wh
Sharp Objects & Tools
Knives, scissors, razors, and tools that could be used as weapons are heavily restricted or prohibited.
Rule: Blades over 2.36 inches (6cm) prohibited in carry-on
Flammable & Explosive Items
Lighters, matches, fireworks, flares, and compressed gases are strictly controlled or banned.
Rule: One lighter allowed; most other flammables prohibited
The Screening Process
Document Check
Boarding pass and ID verified before entering security area
Bin Preparation
Remove laptops, liquids, belts, shoes, and metal items into separate bins
X-Ray Screening
All carry-on items pass through X-ray machine for visual inspection
Body Screening
Walk through metal detector or full-body scanner
Additional Screening (if needed)
Random checks, bag searches, or explosive trace detection swabs
The Liquids Rule Explained (3-1-1 Rule)
The liquids rule is the most commonly misunderstood airport security regulation. In the United States, it's called the 3-1-1 rule. Most other countries follow similar restrictions with slight variations.
The 3-1-1 Rule (United States)
What Counts as a Liquid?
Security considers these items as liquids, gels, or aerosols (even if they seem solid):
- • Water, juice, coffee, soda
- • Shampoo, conditioner, body wash
- • Toothpaste, mouthwash
- • Lotion, sunscreen, moisturizer
- • Makeup (liquid foundation, mascara)
- • Hair gel, mousse, spray
- • Deodorant (gel or aerosol)
- • Perfume, cologne
- • Peanut butter, jam, honey
- • Yogurt, pudding
- • Soup, sauce, salsa
- • Snow globes (liquid inside)
International Variations
| Region | Container Limit | Total Bag Limit | Notes |
|---|---|---|---|
| United States | 3.4 oz (100ml) | 1 quart (1 liter) | Must be in clear, resealable bag |
| European Union | 100ml | 1 liter | Clear, resealable plastic bag required |
| United Kingdom | 100ml | 1 liter | Same as EU; post-Brexit rules unchanged |
| Canada | 100ml | 1 liter | Follows similar rules to US |
| Australia | 100ml | 1 liter | Strict enforcement; bag must seal |
| Japan | 100ml | 1 liter | Very strict; prepare bag in advance |
| China | 100ml | 1 liter | Additional restrictions on some items |
| India | 100ml | 1 liter | Enforcement varies by airport |
Exceptions to the Liquids Rule
- Medications: Prescription and over-the-counter medicines in reasonable quantities (bring prescription label)
- Baby formula & food: Unlimited amounts for infants traveling with you
- Duty-free liquids: Purchased after security in sealed, tamper-evident bags
- Medical liquids: Breast milk, juice for diabetics, liquid nutrition
Common Liquids Mistakes
- Full-size bottles: Even if only partially full, container size matters, not contents
- Multiple bags: You cannot bring two half-full bags instead of one full bag
- Frozen liquids: Ice, frozen water bottles, and frozen gels count as liquids
- Duty-free from home: Liquids bought before arriving at airport must follow 3-1-1 rule
Pro Tip: Buy After Security
The easiest way to avoid liquids restrictions is to buy drinks, snacks, and toiletries after passing through security. Airport shops and duty-free stores are located in the secure area, and items purchased there can be brought on the plane without restrictions (though connecting flights may have additional rules).
Electronics & Battery Rules
Electronic devices and lithium batteries are heavily regulated due to fire risk. Rules vary by device type, battery capacity, and whether the item is in carry-on or checked baggage.
Screening Requirements by Device
Laptops & Tablets
Must be removed from bag and placed in separate bin for X-ray screening
Exception: TSA PreCheck members and some international airports with advanced scanners
Phones & E-Readers
Can stay in bag during screening in most countries
Exception: Some airports require all electronics larger than a phone to be removed
Power Banks & Portable Chargers
Carry-on only — prohibited in checked baggage
Must be under 100Wh (27,000mAh at 3.7V); 100-160Wh requires airline approval
Cameras & Drones
Can stay in bag unless officer requests removal
Spare lithium batteries must be in carry-on with terminals protected
Lithium Battery Limits
| Battery Type | Watt-Hours (Wh) | Carry-On | Checked Bag | Notes |
|---|---|---|---|---|
| Installed in device | Any size | ✓ Yes | ✓ Yes | Device must be off in checked bag |
| Spare batteries | Under 100Wh | ✓ Yes | ✗ No | Terminals must be protected |
| Power banks | Under 100Wh | ✓ Yes | ✗ No | Maximum 2 per person typically |
| Large batteries | 100-160Wh | ⚠ Approval | ✗ No | Airline approval required |
| Very large batteries | Over 160Wh | ✗ No | ✗ No | Prohibited on passenger aircraft |
How to Calculate Watt-Hours (Wh)
Most power banks list capacity in milliamp-hours (mAh). To convert to watt-hours:
Wh = (mAh × Voltage) ÷ 1000
Example 1: 20,000mAh power bank at 3.7V = (20,000 × 3.7) ÷ 1000 = 74Wh ✓ Allowed
Example 2: 30,000mAh power bank at 3.7V = (30,000 × 3.7) ÷ 1000 = 111Wh ⚠ Requires approval
Electronics Best Practices
- • Keep devices charged (security may ask you to power them on)
- • Protect spare battery terminals with tape or cases
- • Pack power banks in carry-on, never checked baggage
- • Have laptop easily accessible for quick removal
- • Check airline-specific battery restrictions before flying
Common Electronics Mistakes
- • Packing power banks in checked luggage (prohibited)
- • Not protecting spare battery terminals (fire risk)
- • Bringing batteries over 100Wh without approval
- • Leaving laptop in bag when removal required
- • Not checking if device is on restricted list
International Differences in Security Rules
While most countries follow similar security principles, enforcement and specific rules vary significantly by region. Understanding these differences helps avoid surprises and confiscated items.
United States (TSA)
- • 3-1-1 liquids rule strictly enforced
- • Shoes must be removed (except TSA PreCheck)
- • Laptops removed from bags
- • Random additional screening common
- • One lighter allowed
- • Food generally allowed
Europe (EU)
- • 100ml liquids limit (1 liter bag)
- • Shoes usually stay on
- • Laptops removed at most airports
- • Stricter on sharp objects
- • Lighters often prohibited
- • Food restrictions vary by country
Asia-Pacific
- • 100ml liquids limit (varies)
- • Very strict enforcement in Japan, Singapore
- • Electronics rules vary widely
- • Additional agricultural restrictions
- • Some countries ban chewing gum
- • Cultural items may be restricted
Regional Security Comparison
| Item | United States | Europe | Asia | Middle East |
|---|---|---|---|---|
| Liquids limit | 3.4 oz (100ml) | 100ml | 100ml (varies) | 100ml |
| Shoes removal | Yes (usually) | Rarely | Sometimes | Sometimes |
| Laptop removal | Yes | Usually | Yes | Yes |
| Lighters | 1 allowed | Often prohibited | Varies | Usually prohibited |
| Food items | Generally allowed | Varies by country | Strict restrictions | Varies |
| Scissors (under 4") | Allowed | Often prohibited | Usually prohibited | Prohibited |
| Power banks | Carry-on only | Carry-on only | Carry-on only | Carry-on only |
| Enforcement style | Moderate | Varies widely | Very strict | Very strict |
Why Enforcement Varies
Security threat levels: Countries with higher perceived threats enforce rules more strictly
Technology differences: Advanced scanners allow some airports to be less invasive
Cultural factors: Some cultures prioritize efficiency, others prioritize thoroughness
Staffing levels: Airports with more security staff can conduct more detailed checks
Recent incidents: Security tightens temporarily after threats or incidents
Country-Specific Restrictions
Australia & New Zealand
Extremely strict on food, plants, and agricultural products
Singapore
Chewing gum prohibited; strict drug laws; e-cigarettes restricted
United Arab Emirates
Alcohol restrictions; medication requires documentation; drones restricted
China
VPN restrictions; certain books/media prohibited; power bank limits
International Travel Tips
- • Research destination country's specific restrictions
- • Pack conservatively when traveling to strict countries
- • Arrive earlier for international flights (3 hours recommended)
- • Keep medications in original packaging with labels
- • Declare all restricted items when required
- • Be respectful of cultural differences in security procedures
Common Security Mistakes (And How to Avoid Them)
Even experienced travelers make security mistakes. Here are the most common errors that cause delays, confiscations, and missed flights.
Oversized Liquids
Mistake: Bringing full-size toiletries or partially full bottles over 3.4 oz
Solution: Buy travel-size containers (under 3.4 oz) and transfer products, or check full-size items in luggage
Power Banks in Checked Luggage
Mistake: Packing power banks or spare batteries in checked baggage
Solution: Always keep power banks and spare lithium batteries in carry-on baggage only
Forgetting About Liquids in Bags
Mistake: Leaving water bottles, coffee, or forgotten toiletries in bag pockets
Solution: Empty all bag pockets before packing; check every compartment before security
Sharp Objects in Carry-On
Mistake: Packing pocket knives, scissors, or razors in carry-on bags
Solution: Check all sharp objects in luggage, or buy disposable razors after security
Not Removing Laptop
Mistake: Leaving laptop in bag when removal is required
Solution: Pack laptop in easily accessible location; remove before reaching conveyor belt
Wearing Metal-Heavy Clothing
Mistake: Wearing belts, jewelry, or shoes with metal that triggers alarms
Solution: Wear slip-on shoes; remove belt and jewelry before screening; use plastic belt
Prohibited Food Items
Mistake: Bringing liquidy foods like yogurt, soup, or salsa through security
Solution: Solid foods are usually fine; buy liquidy foods after security or check them
Not Protecting Battery Terminals
Mistake: Packing loose spare batteries without terminal protection
Solution: Keep batteries in original packaging or tape terminals; use battery cases
Most Commonly Confiscated Items
Liquids & Gels
- • Water bottles
- • Full-size shampoo
- • Toothpaste tubes
- • Sunscreen bottles
- • Liquid makeup
- • Peanut butter jars
Sharp Objects
- • Pocket knives
- • Scissors (over 4")
- • Razor blades
- • Box cutters
- • Sewing needles
- • Corkscrews
Other Items
- • Lighters (in some countries)
- • Sporting equipment
- • Tools
- • Spray paint
- • Fireworks
- • Self-defense items
How to Pass Through Security Faster
With proper preparation and smart packing strategies, you can significantly reduce your time at security checkpoints. Here's how experienced travelers breeze through security.
The 5-Minute Security Strategy
Before Airport
Pack smart
In Line
Prepare items
At Bins
Quick removal
Body Scan
Follow instructions
After Scan
Repack quickly
Smart Packing Strategy
Use a TSA-Compliant Bag
Choose bags with laptop compartments that open flat for easy screening. Some bags are designed to keep laptops inside during screening.
Pack Liquids on Top
Keep your liquids bag in an easily accessible pocket or on top of your carry-on for quick removal.
Laptop in Separate Compartment
Store laptop in its own compartment so you can remove it without unpacking other items.
Minimize Metal Items
Pack metal items in checked luggage when possible. Use plastic or fabric alternatives for belts and accessories.
Time-Saving Preparation
Wear Slip-On Shoes
Choose shoes without laces that you can remove and put back on quickly. Avoid boots with many buckles.
Empty Pockets Before Line
Put phone, wallet, keys, and coins in your carry-on before reaching security to avoid fumbling at bins.
Remove Belt and Jewelry Early
Take off belt, watch, and metal jewelry while waiting in line and place in your bag or jacket pocket.
Have ID and Boarding Pass Ready
Keep documents easily accessible in hand or outer pocket. Use mobile boarding passes when possible.
Bin Organization Strategy
Bin 1
Shoes, belt, jacket
Bin 2
Laptop (alone)
Bin 3
Liquids bag, small items
Bin 4
Carry-on bag
Pro tip: Send bins through in reverse order (bag first, shoes last) so you can repack in the correct sequence
Expedited Security Programs
TSA PreCheck (US)
Keep shoes, belt, and jacket on; laptop stays in bag; $78 for 5 years
Global Entry (US)
Includes TSA PreCheck plus expedited customs; $100 for 5 years
CLEAR (US)
Biometric identity verification; skip to front of security line; $189/year
International Programs
EU: Registered Traveller; UK: Fast Track; Canada: NEXUS
Additional Time-Saving Tips
- • Choose security lanes with business travelers (usually faster)
- • Avoid lanes with families with young children
- • Use airport apps to check security wait times
- • Arrive during off-peak hours (mid-morning, early afternoon)
- • Consider checking a bag to reduce carry-on screening time
- • Watch travelers ahead of you to learn the process
Frequently Asked Questions
Still have questions? Check the official TSA website (for US travel) or your destination country's aviation authority for the most current and detailed security regulations.
Quick Navigation
Updated Regularly
This guide is reviewed and updated quarterly to reflect current TSA and international security regulations.
Last updated: January 2026
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