There are no UAV rules in Bulgaria. Hold yourself to the rules that you are using at home.
so many people can fly there UAV here.
You will get reserved airspace. Bulatsa will make a Notam when you are flying, also small planes/helicopters have to take another route.
Maximum take-off weight:
Maximum horizontal distance:
Distance Airports / Heliports:
Useful link: Bulgarian Air Traffic Services Authority (BULATSA)
Contact information: firstname.lastname@example.org