City Business Directories were created by private publishers and include individuals as well as businesses. Historically, what they included and how the geographical coverage was handled, varied by publisher. Many, but not all, of these directories did have a reverse lookup function by address. Other points to note:
The Library of Congress has many of these directories in print, on microform, and available electronically. Many of these directories do not have catalog records so you must request them in person by submitting a paper request in either the Main Reading Room or the Science & Business Reading Room. You will request them by place (city/county) and year(s). An inventory of directories in microformat can be seen at the link below is an inventory of directories in microform. These directories can only use them in the Microform and Electronic Resources Center but it is self-serve. Lastly, some of these directories have been digitized in subscription databases like Ancestry.com and Archives Unbound as well as by the Library's web. See the entries below for information on access.
The Library of Congress also has a collection of telephone books from places around the United States and abroad. None of these items is contained in the catalog. You must request them in person and it is best done in the Science and Business Reading Room. There is some inventory for the United States—see link below—but it isn't complete. The Library also has many telephone directories from around the world but there is no comprehensive inventory for them all. However, staff have been creating individual inventories for some places like countries in Eastern Europe and the Balkan area so over time those may have inventories as well.
Please see a reference librarian for assistance if you have any questions about any of these directories. The subscription resources marked with a padlock are available to researchers on-site at the Library of Congress. If you are unable to visit the Library, you may be able to access these resources through your local public or academic library.