Johannes Haas was born in 1971 and first completed an apprenticeship as a tax clerk. He then studied law in Göttingen and completed his clerkship in Frankfurt am Main and New York. He has worked at Haas & Haas since he was admitted as a lawyer in 2000 and has been a partner since 2005. He has been a specialist lawyer for tax law since 2004. He also qualified as a tax adviser in the same year.