The cheapest flight to Sofia you can get by boooking 39 days before departure.
The most popular airlines on the route Cologne - Sofia: Ryanair (FR), Wizz Air (W6), Air Berlin (AB).
The cheapest flights you can book on the route Cologne - Bonn Airport (CGN) - Sofia Airport (SOF).
Direct flights last about 2h 25min.
Direct flights available 7 days a week.
Direct flights: Ryanair (FR), Wizz Air (W6).