The Audit Office is an independent body that audits the budgetary and economic management of the state capital of Mainz independently and without instruction, reporting its findings directly to the mayor.

Its tasks are regulated by municipal law and, in addition to auditing the annual and consolidated financial statements, essentially include auditing the regularity, expediency, and economic efficiency of the administration.

Other tasks include the anti-corruption office and the reporting office in accordance with the Whistleblower Protection Act, as well as auditing information security.