What happens if I do not select a seat? If you do not select a seat, one will be assigned to you randomly during the check-in process. Related articles Can I change my seat after purchasing it? How can I make sure I sit next to my family? In Brazil, is there an additional charge to assign adjacent seats to a passenger under 16 years of age and their accompanying adult? What is included in the Extra fare? Can I select my preferred seat when checking in online?