Do carry-on rules differ between countries?

Yes, significantly. US airlines impose no weight limit on carry-ons; most Asian airlines enforce 5–7 kg with consistent enforcement. EU and UK carriers typically apply a 7–10 kg limit with variable enforcement. The size limits also vary, with US airlines allowing slightly larger bags than European equivalents.

What happens to my carry-on at a connecting flight security check?

At most international connections, you pass through the transit security checkpoint of the country you're connecting through. That country's rules apply, including liquid restrictions, prohibited items, and bag checks. Your main airline's carry-on allowance still applies for what goes on the plane, but the transit security process follows local rules.

Do codeshare flights follow the operating airline's rules or the ticketing airline's rules?

For carry-on baggage, the operating airline's rules generally apply — meaning the airline whose crew and aircraft are actually operating the flight. If you book through British Airways but fly on a Cathay Pacific codeshare, Cathay's 7 kg limit applies. Always check which airline is physically operating your flight.

Is airport security stricter in some countries than others?

Yes. Security screening is most thorough in Israel (Ben Gurion Airport), the US (TSA), and the UK (post-liquids-plot enhanced protocols). Many Asian airports enforce carry-on weight and size checks at the gate more consistently than European airports. Some smaller airports in developing countries have minimal physical screening despite nominal requirements.

What should I know about carry-on rules flying through the Middle East?

Gulf carriers (Emirates, Qatar Airways, Etihad) enforce a 7 kg economy carry-on limit. Business and first class allowances are considerably higher (12–15 kg). Dubai, Doha, and Abu Dhabi airports are major transit hubs with full security screening at transit, including liquid rules that follow international standards.

International Carry-On Rules: What Changes When You Fly Abroad

Most travelers know the carry-on rules for their home airline. But when you book an international itinerary — especially one with connections, codeshares, or a mix of carriers — the rules that govern your cabin bag can shift dramatically depending on which airline is flying the aircraft and which country's airport you're passing through.

This guide explains how carry-on rules differ by region, what to expect at international security checkpoints, and how codeshare and alliance arrangements affect your allowance.

How Carry-On Rules Differ by Region

United States: Generous Rules, Minimal Enforcement

The US stands apart from the rest of the world in its approach to carry-on regulation. American carriers — including American Airlines, Delta, United, Southwest, JetBlue, and most domestic low-cost carriers — impose no weight limit on carry-on bags. The only standard restriction is size.

Typical US carry-on size limit: 22 × 14 × 9 inches (56 × 36 × 23 cm), including wheels and handles.

This is slightly larger than the standard European limit, meaning a bag that complies with US airline rules may still be over-size on European carriers. US airports also tend to be less rigorous about enforcing size rules at the gate — bags that are marginally oversized frequently make it through unchallenged on domestic flights.

The exception is budget US carriers: Spirit, Frontier, and Allegiant charge for overhead carry-ons but still impose no weight limit. Their free personal item allowance (under-seat bag) is measured by size only.

What to expect at US airport security (TSA):

Laptop must be removed from bag and screened separately (unless you have TSA PreCheck)
Liquids (3-1-1 rule): containers ≤3.4 oz (100ml), in a 1-quart clear bag
Shoes must be removed (except at PreCheck lanes)
Jackets and belts must be removed
No routine carry-on weight checks

Europe: 7–10 kg Limits, Variable Enforcement

European carry-on rules are more varied than the US, with weight limits standard across both full-service and budget carriers, but enforcement that ranges from highly consistent to essentially non-existent.

Typical European carry-on dimensions: 55 × 40 × 23 cm or 56 × 45 × 25 cm (smaller dimension is more common among budget carriers).

Weight limits by carrier type:

Budget LCCs (Ryanair, Wizz Air, Vueling): 10 kg — actively enforced
Lufthansa, Swiss, Austrian: 8 kg — occasionally checked
Air France, KLM: 12 kg — rarely checked
British Airways: 23 kg combined — essentially not enforced
easyJet: No weight limit — not enforced

European airport security follows the EU/UK standard:

Liquids: 100ml per container, in a 1-litre transparent bag
Laptop removed separately (unless airport has CT scanners)
Shoes remain on at most EU airports (except UK, which often requires removal)

The major shift for US travelers arriving in Europe is the liquids rule: the volume is the same (100ml per container), but the European bag format (exactly 1 litre) can be smaller than some US quart-size bags. Bring your own compliant bag.

Asia-Pacific: Strictest Limits, Most Consistent Enforcement

Asia-Pacific carriers operate the strictest carry-on regime in the world, with low weight limits and consistent enforcement that catches travelers who are accustomed to US or UK norms.

Typical weight limits:

Chinese carriers (Air China, China Eastern, China Southern, Hainan): 5 kg
Singapore Airlines, Cathay Pacific, Vietnam Airlines, Malaysia Airlines, Qantas, Air New Zealand: 7 kg
Japan Airlines, ANA, Scoot: 10 kg
AirAsia: 7 kg — strictly enforced

Size limits are also more restrictive in parts of Asia. Some carriers set a maximum of 55 × 38 × 20 cm or similar, which is tighter than typical European limits. A bag that easily fits Ryanair's size sizer may not fit within an AirAsia or Singapore Airlines limit.

What to expect at Asian airport security:

Weight checks are most common at check-in desks and gate boarding in China, Japan, South Korea, and Singapore
Chinese airports at major hubs (PEK, PVG, CAN) consistently weigh carry-ons
Security technology in Singapore, Japan, and South Korea is advanced — expect additional screening of electronics at high-traffic airports
Japan requires laptops and tablets to be powered on for inspection on some flights
Liquid rules follow the international 100ml standard

For travelers flying to or through China, the 5 kg limit requires specific preparation: a lightweight bag (under 1.5 kg empty) and careful selection of contents are essential.

Middle East: Gulf Carrier Hub Rules

The major Gulf carriers (Emirates, Qatar Airways, Etihad) are premium airlines with moderate carry-on rules that sit between the permissive US standard and strict Asian enforcement.

Economy class weight limits:

Emirates: 7 kg
Qatar Airways: 7 kg
Etihad: 7 kg
flydubai: 7 kg — strictly enforced
Air Arabia: 7 kg

Business and first class passengers on Gulf carriers typically receive 12–15 kg carry-on allowances, making the weight limit largely academic for premium cabin travelers.

Dubai (DXB), Doha (DOH), and Abu Dhabi (AUH) are among the world's busiest transit hubs. Security at these airports follows international standards, including the 100ml liquid rule. Transit passengers connecting through the Gulf do not typically need to re-clear immigration but must pass transit security — which applies the host country's rules.

Canada, Australia, and New Zealand

These countries follow the international 100ml liquid standard and generally mirror US or UK norms for carry-on enforcement, depending on the carrier:

Canada: Domestic carriers (Air Canada, WestJet) follow the US model — no weight limits, size-only enforcement. Security (CATSA) mirrors TSA procedures including laptop removal.
Australia: Qantas enforces 7 kg; Jetstar enforces 7 kg strictly; Virgin Australia enforces 7 kg. Australian airport security follows UK/EU standards including shoe removal at many airports.
New Zealand: Air New Zealand enforces 7 kg. Security is similar to Australia.

Codeshare and Alliance Rules

Codeshare flights — where one airline sells tickets for a flight physically operated by a different airline — can cause confusion about which baggage rules apply.

The general rule: The operating airline's carry-on rules apply on board. The ticketing airline's rules govern the overall booking (loyalty points, check-in procedures) but not what gets accepted at the aircraft door.

Example: A British Airways flight number on a ticket that is actually operated by Japan Airlines (a common oneworld codeshare) follows Japan Airlines' 10 kg carry-on limit — not British Airways' 23 kg combined limit.

How to check: Your itinerary or booking confirmation typically indicates the operating airline separately from the ticketing airline. Look for language like "operated by" or "marketed as." When in doubt, look up the flight number on the operating airline's website.

Alliance considerations: Star Alliance, oneworld, and SkyTeam have reciprocal frequent flyer agreements but do not standardize carry-on rules across member airlines. Each airline maintains its own baggage policy regardless of alliance membership.

What to Know at Transfer Security

International connections often require passengers to pass through security at the transit airport. Key rules:

Duty-free liquids purchased before your connection may be confiscated at transit security in some countries. This particularly affected passengers transiting through UK airports with duty-free from certain countries — check current rules for your specific route before purchasing at the origin airport.

Prohibited items follow the transit country's rules. An item permitted in your origin country may not be permitted in your transit country. This commonly affects:

Food items with agricultural restrictions
Certain knives or tools
High-powered lasers (prohibited in many countries)
Medication without documentation

Carry-on size and weight are checked by the operating airline for your onward flight, not at the transit security checkpoint itself. However, if your bag has been gate-checked on the first leg, you may need to retrieve it and recheck it for your onward flight depending on the airline and airport.

Practical Tips for International Travel

Research each operating airline separately. On multi-leg international itineraries, each segment may be on a different carrier with different rules. Identify the most restrictive rule in your itinerary and pack to that standard.

Pack to the strictest limit on your itinerary. If one flight segment is on an Asian carrier with a 7 kg limit, pack to 7 kg even if your other segments have no limit.

Carry documentation for exceptions. Medications, baby formula, and duty-free liquids that you're carrying under exemption should be accompanied by documentation. Keep prescriptions, receipts, and tamper-evident bags accessible.

Know which airports enforce weight checks. Chinese, Japanese, and Southeast Asian airports consistently weigh carry-ons at check-in. European and US airports rarely do. Middle Eastern airports are variable.

Use the transit time productively. If you have a long layover at a hub like Dubai, Singapore, or Tokyo, you can reorganize your bags, dispose of items you no longer need, or purchase compliant liquids at the airside shops.

The Bottom Line

International carry-on rules vary enormously by region. US travelers enjoy the world's most relaxed carry-on regime and may be surprised by the 5–7 kg limits enforced on Asian carriers or the liquid rules applied throughout Europe. The safest approach for any international itinerary is to research each operating airline and each transit airport, pack to the most restrictive weight limit in your journey, and keep any exempted items (medications, baby milk, duty-free) organized and easily accessible at security.