Most of the foreign telephone directories held by the Library of Congress are uncataloged, we have therefore compiled this list of Bulgarian directories as a finding aid for our staff and researchers. These directories cover Bulgaria between the years 1936-2011. In addition to the uncataloged directories listed below, the Library also holds a handful that are cataloged and may be requested using the online catalog. To locate these directories, search the Library of Congress Online Catalog using subject keywords such as "Bulgaria" and "directories," or the name of a city plus "directories." In addition to telephone directories, this kind of search also yields business/address directories from Bulgaria.

The finding aid, which represents our holdings as of January 2020, is arranged by city, and then by the year prominently displayed on the cover of the piece, which may or may not be the actual date of publication (i.e., a directory will often have one year in large print on the cover, and a different, usually earlier, year of publication elsewhere). Directories that cover all of Bulgaria appear first in the list. The type of directory is indicated by the words "residential," "organizational," or "both," for directories that include both business and private numbers. At the end of the finding aid there is a section for directories of institutions, such as labor unions, universities, and government committees.

The notes field is used to provide further information about the directory if needed. For example, many directories from Bulgaria feature a large town, but also provide listings for smaller locales. These smaller locales are often listed in the notes field.

All directories are in the Cyrillic alphabet unless otherwise noted. In addition to an alphabetical arrangement by surname, business name, occupation or trade, many directories provide a numerical listing of entries arranged by phone number to determine who held a particular number for a given year. This feature is indicated in the notes field with the words "numerical index." Sometimes the notes field will have a statement with words such as "registrirani do," followed by a date. This statement is taken either from the title page or title page verso and can be translated loosely as "numbers registered as of a given date." It merely offers more precise dating for the contents of the directory.

Besides using printed telephone directories, a reader may find it helpful to use online directories available for free on the Internet. The telephone portal site Infobel External provides a database of business entries for each European country, including Bulgaria. There are no listings for private individuals at this site.