CPA firm In association with H R Block. H R Block is the world’s largest tax services provider, having prepared more than 650 million tax returns since 1955. There are approximately 12,000 company-owned and franchise retail locations in all 50 states, Puerto Rico and other U.S. territories, and on U.S. military bases around the world. An H R Block branded retail office is located within five miles of most Americans. In fiscal 2014, H R Block had revenues over $3.0 billion and prepared 24.2 million tax returns worldwide.