If you purchased your ticket at a travel agency, you can apply for pre-seating service, Excess baggage at [My Trip] on our website. Purchaisng pre-seating service and Excess baggage should be made 24 hours before departure. You can also purchase them through our Customer Service Center(82-1600-6200). (Some tickets purchased through specific travel agencies are not yet available so please contact the original channel of your ticket.)
For more additional details regarding the pre-seating service, please refer to our homepage [Service > Additional Service > Advance seat assignment].