Do I need my passport to be valid for a period exceeding the duration of my trip?
The basic rule is that your passport should be valid for at least six months from the date of your trip.
Each country has its own requirements regarding the validity of passports or substitute travel documents. Examine carefully the information on the country in the "Travel Assistant" section, Travel Documents subsection. If necessary, you can request information on the matter from the embassy of the country concerned in Sofia or in another country.