This department is responsible for debt management and the annual debt report for the state capital of Mainz. Its responsibilities include planning and controlling financial and liquidity positions to ensure solvency at all times, as well as processing guarantees in favor of third parties. It is also responsible for issuing bonds and investments in accordance with the investment guidelines.

The Controlling department is responsible for preparing the financial reports on the annual reporting dates of April 30 and September 30 and for controlling in Office 20.

The Foundation Administration Department is responsible for processing all independent and dependent foundations and estates in the state capital of Mainz. This also includes asset management in the form of the foundation's own land and real estate.