Allegiant Air has officially secured Sun Country Airlines’ FAA Air Operator Certificate, a mandatory regulatory milestone in the $1.5 billion merger closed in May 2026. The transfer consolidates legal ownership of the operating certificate under Allegiant, enabling future operational integration into a single FAA-certified entity. Both carriers will continue flying separate metal and crews for 18 to 24 months while safety management systems, manuals, and training standards merge. Passengers cannot yet book mixed itineraries on one ticket; bookings remain carrier-specific. The combined airline will eventually operate solely under the Allegiant brand, with Sun Country’s standalone identity ending post-FAA single certificate approval.