Seoul fares swing with festival demand and airport choice between ICN and GMP.
Spring cherry blossom periods and autumn foliage weekends are when Seoul pricing tightens fastest, especially on Northeast Asia corridors. Shoulder windows in late May and October often keep weather comfortable while avoiding the sharp fare jumps seen during major holiday travel bursts.
Seoul has a split-airport logic that changes trip planning: Incheon (ICN) handles long-haul and most international schedules, while Gimpo (GMP) is better for short regional hops. AREX express service connects ICN to Seoul Station in roughly 43 minutes, which makes airport transfer predictability one of Seoul's practical advantages.
Korean Air and Asiana anchor full-service capacity, but low-cost carriers like T'way, Jin Air, and Jeju Air shape short-haul pricing pressure into Seoul. That mix means you can often save by comparing fare bundles rather than base fares alone, because baggage and seat policies differ materially by carrier type.
Late May and parts of October often offer better value than peak spring-blossom or summer windows. Prices can jump around major Korean holidays and high-demand festival periods. Midweek departures usually give more pricing flexibility.
Typical nonstop London to Seoul flights are around 11 - 13 hours depending on routing and winds. One-stop itineraries can be cheaper on some dates but usually increase total travel time significantly. Comparing total elapsed time against fare savings is key on this city pair.
South Korea generally admits UK and most EU passport holders without a visa for short stays, but entry conditions can change. Passport validity and arrival-card or pre-travel requirements may still apply. Always verify official rules before final payment.