HK Express Carry-On Rules: Size, Weight & Fees (2026)

HK Express (IATA: UO) is Hong Kong's only ultra-low-cost carrier, operating from Hong Kong International Airport (HKG) to destinations across Japan, South Korea, Taiwan, and Southeast Asia. The airline was founded in 2013 and acquired by the Cathay Pacific Group in 2019, but it continues to operate entirely independently as a budget carrier with its own fare structure, baggage rules, and fleet of Airbus A320 and A321 aircraft. For passengers accustomed to full-service carriers like Cathay Pacific itself, the difference is significant: checked baggage is not included in any base fare, and carry-on limits are both tight and actively enforced.

HKG is one of Asia's best-run international airports, and low-cost carrier gates at the airport are routinely equipped with bag gauges. HK Express gate staff use them.

HK Express Carry-On Allowance at a Glance

Item	Dimensions	Weight
Cabin bag	56 × 36 × 23 cm (22.0 × 14.2 × 9.1 in)	7 kg max
Personal item	Small bag, fits under seat	No stated limit

Both items are permitted in the cabin. The 7 kg limit applies to the cabin bag. The personal item has no published weight limit, but it must genuinely fit under the seat — a full-size backpack used as a "personal item" will not pass at an enforced HK Express gate.

Cabin Bag Dimensions

HK Express sets the cabin bag limit at 56 × 36 × 23 cm, measured with wheels, handles, and any external pockets included. In inches: 22.0 × 14.2 × 9.1.

The 56 cm height is one centimetre shorter than some regional carriers (such as Peach Aviation's 57 cm). Bags marketed as 22-inch carry-ons sometimes exceed 56 cm when handles are included — measure your bag with the handle fully retracted before travelling. The 36 cm width and 23 cm depth are standard across most Asian LCCs and fit comfortably in the overhead bins of the A320 and A321 fleet.

A cabin bag that fits within these dimensions at approximately 35–38 litres capacity is appropriate for HK Express.

Personal Item

HK Express permits one small personal item in addition to the main cabin bag. Acceptable personal items include:

• Handbags and purses
• Small backpacks
• Laptop bags and sleeves
• Small tote bags

The personal item must fit under the seat in front of you. HK Express does not publish specific dimensions for the personal item, but gates are enforced and an oversized personal item — particularly a hiking-style daypack or a full laptop backpack — risks being counted as a second cabin bag, which is not permitted.

Packing electronics (laptop, tablet, charger) into a slim laptop bag and using this as the personal item is a practical approach. It keeps the personal item genuinely compact and leaves your 7 kg cabin bag allowance available for clothing and other items.

Enforcement at HKG

Hong Kong International Airport maintains consistent low-cost carrier enforcement standards. Passengers flying HK Express should expect:

Bag gauge frames at the gate. HKG equips most LCC departure gates with metal size gauge frames matching the permitted cabin bag dimensions. Gate staff will direct passengers to test their bags when there is any question about size.

Weight checks at check-in. The 7 kg limit is checked at the check-in counter. If your cabin bag exceeds 7 kg, you will be required to purchase checked baggage at the airport counter rate, which is substantially more expensive than rates available before departure.

Gate-level fee collection for oversize. Bags that pass check-in but fail a gate size check will be redirected to the hold. The fee collected at the gate is the most expensive option available.

Consistent reports from passengers across Japan, Korea, and Southeast Asia routes confirm that HK Express is one of the more diligent LCCs in Asia when it comes to carry-on enforcement, particularly on departures from HKG.

Fee Structure

HK Express does not publish a fixed gate excess baggage rate on its website — airport rates are set dynamically and are always significantly higher than pre-purchased rates. As a general guide:

Purchase timing	Relative cost
At booking (website/app)	Cheapest
After booking, before check-in	Moderate
At airport check-in counter	Expensive
At the gate	Most expensive

If you know you need a checked bag, book it at the time of purchase. Adding it later is more expensive; paying at the airport or gate is considerably more expensive still.

Checked Baggage Is Not Included

HK Express base fares — referred to as the "Starter" fare — include only the cabin bag allowance. Checked baggage is a paid add-on for all passengers on all fare types. This is a common source of surprise for passengers used to full-service carriers, particularly those who fly with Cathay Pacific regularly and expect group-wide policies.

If you are travelling with standard luggage for a week-long trip, plan to purchase a 20 kg or 30 kg checked bag option at booking. Options are also available in 10 kg increments on some routes.

Cathay Pacific Group: What the Relationship Does Not Mean

HK Express is wholly owned by Cathay Pacific Group, which acquired it in 2019. The ownership has led to improvements in network connectivity — HK Express feeds the Cathay hub at HKG — but it has not changed HK Express's operating model. Specifically:

• Cathay Pacific Asia Miles membership does not provide carry-on or checked baggage benefits on HK Express
• Cathay Pacific elite status (Marco Polo Club, Cathay status tiers) is not recognised by HK Express
• HK Express has no frequent flyer programme of its own
• Booking HK Express flights through the Cathay Pacific app does not change baggage entitlements

The two airlines operate on completely separate fare structures and policies.

Security at HKG

Hong Kong International Airport follows the standard international 100 ml liquids rule for carry-on items:

• Liquids, aerosols, and gels must be in containers of 100 ml or less
• All containers must fit inside one clear, resealable plastic bag of maximum 1 litre capacity (approximately 20 × 20 cm)
• The bag must be removed from your carry-on and presented separately at security

HKG security is efficient and consistent. Liquids rules are enforced thoroughly.

Power banks must be carried in the cabin, not in checked baggage. Power banks over 100 Wh require airline approval; those over 160 Wh are prohibited.

Practical Tips for HK Express Passengers

Weigh your cabin bag before you leave home. Seven kilograms sounds generous but is reached quickly with a laptop, charger, and a few days of clothing. A standard empty cabin bag weighs 1–1.5 kg, leaving approximately 5.5–6 kg of packing capacity.

Use a lightweight carry-on. Ultralight cabin bags in the 500–900 g range are widely available and maximise usable packing weight. Avoid heavily framed rollers, which can weigh 2 kg or more empty.

Pre-purchase any checked baggage. The price differential between booking-time rates and airport rates is significant. If your trip is longer than two to three nights, consider whether carry-on only is realistic.

Keep your personal item genuinely small. A slim laptop sleeve or a small handbag works. A full 20-litre daypack will attract scrutiny at an enforced HKG gate and may be counted as a second carry-on item.

Test your bag dimensions. Bags marketed as 22-inch rollers often include wheel height in that measurement or, alternatively, exclude it. Measure your specific bag with all pockets loaded and handles retracted to confirm it fits within 56 × 36 × 23 cm.

The Bottom Line

HK Express offers competitive fares across its Asia network, but the trade-off is a strict carry-on policy and consistent enforcement at Hong Kong International Airport. The 56 × 36 × 23 cm, 7 kg limit allows for a practical cabin bag, and the personal item allowance gives extra flexibility for a laptop or handbag. Checked baggage is not included and must be purchased separately — do it at booking to avoid significantly higher airport rates. Cathay Pacific status and miles offer no advantage on HK Express, regardless of the group ownership structure. Pack within the limits, buy any checked bag in advance, and HK Express is a straightforward and efficient way to travel across Asia from Hong Kong.

---

Carry-on rules are subject to change. Always verify current policy at hkexpress.com before travel.