The PMCC maintains the Post Office Directory, the most accurate list of Post Offices available. These listings detail postal operations in all 50 states, some Canadian provinces, and U.S. possessions. Each year the PMCC holds an annual Convention in a different part of the U.S. hosted by member(s) of the club, offering free postmarks, cachets, benefit auctions, exhibits, tours and more. The Post Mark Collectors Club is affiliate #62 of the American Philatelic Society (APS). It held its 49th annual convention in New London, Connecticut on July 21, 2010.