Turkish Airlines online check-in and seat-change timing
Check the actual flight operator first: the seat-selection conditions do not cover codeshare flights operated by another airline. Resolve a paid-seat preference before you start check-in when possible. Turkish allows a paid seat to be changed to another seat in the same category through Manage booking without an additional charge before the online check-in process starts. That is a different cutoff from the end of online check-in. Free seat selections can be changed through the end of online check-in under the published conditions. Do not extend that rule to every paid seat or a move into a more expensive category. Review the current seat and any displayed charge before completing check-in, then follow the airport and boarding instructions issued for the journey.

Important unknowns
- Airport and boarding deadlines remain itinerary-specific.
- Live canonical owner and nearest-page content are UNKNOWN because the sitemap index could not be retrieved.
Sources and last checked
- Seat selection terms and conditionshttps://www.turkishairlines.com/en-us/any-questions/seat-selection-terms-and-conditions/