Cars from local suppliers at both airport terminals, with the keys handed over on arrival.
Sofia is one of the few European capitals where the airport question has a real answer other than the car. Metro Line 4 runs from under Terminal 2 into the middle of town in about twenty-five minutes for a couple of euros, and it does not sit in traffic. If your week is a city week, that is the better move and this page is not for you.
Collecting at the airport is worth it for a different reason: geography. Sofia Airport is on the eastern edge of the city, on the same side as the A1 and within reach of the ring road. Take the car here and your first drive is outward, onto open road. Take it from a city office instead and your first drive is through the centre in whatever traffic the hour gives you, before you have adjusted to a strange car.
So the question is not really where the cheapest desk is. It is which direction you are going on day one. Anyone heading for Plovdiv, Rila, Borovets or Bansko is better off never entering the centre with the car at all.
None of them are dramatic, and all three are avoidable if you know about them before you land.
The two terminals are separate buildings roughly 1.5 km apart, and your supplier arranges the handover at one specific one. Low cost carriers generally use Terminal 1 and most scheduled full-service flights use Terminal 2, but that is a habit rather than a rule, so read the terminal off your own boarding pass and make sure the booking matches it. If it does not, the free inter-terminal shuttle fixes it in about ten minutes, which is annoying rather than serious. There is a whole page on this: see Terminal 1 and Terminal 2.
Local operators do not run branded desks in the arrivals hall, and that surprises people who expect a row of counters. What you get instead is a named person, a phone number and a meeting point, all confirmed in writing when the booking is accepted. Save that message offline before you fly, because arrivals is exactly where roaming decides to misbehave. If you cannot find your contact, call rather than wait: they are usually in the short-stay car park opposite, not inside the hall.
The exit road funnels towards Brussels Boulevard and the centre, which is the wrong way for most people collecting a car here. Set your destination before you move off, not at the first roundabout. If you are heading east or south, you want the ring road, and taking it costs you nothing but saves a slow crossing of a city you were not planning to drive through.
The airport sits on the eastern edge of the city, which is the same side the A1 leaves from. You join the motorway without touching the centre.
15 minutes to the motorway
Around the southern ring, past the Vitosha foothills. Slower than the A1 but still an edge-of-city route rather than a crossing.
25 minutes to open road
South through the outer suburbs and straight into switchbacks. The only one of these where the climb starts almost immediately.
40 minutes to Aleko
The one direction where the car is the weaker option. Metro Line 4 runs from Terminal 2 to the middle of town for the price of a coffee.
25 minutes, traffic permitting
Times are for a clear run outside rush hour. Sofia traffic thickens sharply between 08:00 and 09:30 and again from 17:00, and the ring road is the part that suffers most.
Airport availability moves faster than city availability, because everyone wants the same morning slots. The list is live, so your dates give you the real answer.
Yes, provided the supplier knows which flight it is. Give the flight number when you book and the handover is scheduled against the arrival rather than against a clock time, so a two-hour delay simply moves it. What causes trouble is a changed flight nobody was told about, so if you rebook, message the supplier the same day.
Usually yes, and usually free, because both are the same airport as far as the supplier is concerned. Say so at booking rather than assuming, since the return is arranged as a meeting like the collection is, and the driver needs to be at the right building.
Some suppliers add a modest out-of-hours fee for handovers late at night or very early, and some do not charge at all. It is shown on the listing before you book, so compare the total rather than the daily rate if your flight lands at an awkward hour.
Almost always full to full: you collect it full and bring it back the same way. There is a filling station on the approach road to both terminals, which is the sensible last stop. Keep the receipt until the car is checked in.
Only if they are named on the agreement. Additional drivers are added at the handover for a small daily fee, and both people need their licence there. An unnamed driver at the wheel voids the cover, which matters more on the motorway east than anywhere else on this trip.