https://www.flyuia.com/ua/en/promotions/upgrade-to-business"Upgrading the level of comfort at a special price is available to passengers who purchased Economy Class tickets, including tickets bought at reduced prices during the periods of promotions and special offers and / or issued for miles, for UIA’s own regular flights operated under the PS 0001-0999 codes (except for the flights to / from Dnipro, Beijing, Tel Aviv, Zurich, Geneva, Paris PS127 / 128, Nice), with the date of departure from September 15 until December 10, 2018 inclusive (for the flights to / from Palma de Mallorca on any day until September 28, 2018)."