Atlanta International Airport (ATL), one of the busiest airports in the world, is home to Frontier Airlines. You can check in online up to 24 hours before your trip through the Frontier Airlines website or mobile app, ensuring a seamless start. By doing this, you can select your seat and receive a mobile boarding permit, which will save you time at the airport. Use the self-service kiosks to swiftly print your baggage tags and boarding pass if you would rather check in at the airport. If you require assistance, check-in desks are manned as well. To give yourself ample time for security and check-in, arrive at least two hours before your trip. Visit: Frontier Airlines Atlanta Terminal