The cheapest flight to Sofia you can get by boooking 48 days before departure.
The most popular airlines on the route Helsinki - Sofia: Turkish Airlines (TK), KLM (KL), Lufthansa (LH).
The cheapest flights you can book on the route Vantaa (HEL) - Sofia Airport (SOF).
There is no direct flight on the route from Helsinki to Sofia
Il volo con scalo più breve dura 5h 4min.