SixT Car Hire and Tourist Services by johngayton
The SixT group is predominantly a multi-national car hire company but here in Sofia also provides other tourist services such as hotel reservations, tours, folk nights and currency exchange. I have only used their services once when I got half-price deal at the Princess Hotel through them but they seem very efficient and despite the hotel being literally across the road it was actually cheaper to book and pay through SixT than to book direct with the hotel.
The office is a minute or 2's walk across the road from both the Central Bus and Train Stations (at the front of the Princess Hotel) and is worth dropping into if you have arrived without pre-booked accommodation. Staff are multi-lingual, helpful and all major credit cards are accepted.
Unfortunately they don't seem to have any hotel info on their website but the phone number below is for their hotel services.
+ 49 (0) 180 - 5 00 22 01