American Philatelic Society (APS)
With nearly 32,000 members in more than 110 countries, the American Philatelic Society is the largest, non-profit organization for stamp collectors in the world. Founded in 1886, the American Philatelic Society serves collectors, educators, postal historians, and the general public by providing a wide variety of programs and services.
National Stamp Dealers Association
The National Stamp Dealers Association was founded in 1995 to join small and large stamp dealerships together in a friendly organization with reasonable dues and membership requirements.