Ten years after the Securities and Exchange Commission mandated the conversion of corporate financial statements to machine-readable formats, there is still no analogous mandate for state and local government Comprehensive Annual Financial Reports (CAFRs). We explore the challenges and benefits of migrating from PDF CAFRs to machine-readable filings using eXtensible Business Reporting Language (XBRL). After explaining the benefits of machine-readable audited municipal financial data, we consider the challenges of creating and implementing an XBRL taxonomy for this sector and the impact a filing mandate would have on state and local governments. To better assess the challenges, we update a CAFR taxonomy previously published by Neal M. Snow and Jacqueline L. Reck and apply it to a city in Florida. While corporate XBRL filers generally use third-party filing firms, they can also use open-source software, low-cost licensed software, or both to produce the filings. Providing a variety of low-cost alternatives to state and local governments helps mitigate the challenge of providing affordable filings.