The office of the controller performs an internal auditing function. Internal auditing is an independent appraisal function established within an organization to examine and evaluate the activities of the organization. A general statement of purpose, authority and responsibility for the office of the controller is included in the county's home rule charter and administrative code.

All audits begin with objectives, and those objectives determine the type of audit to be conducted and the auditing standards to be followed. The Government Auditing Standards, issued by the Comptroller General of the United States, provides auditing guidelines for financial and performance audits. Professional standards are also promulgated by the American Institute of Certified Public Accountants. Standards for the Professional Practice of Internal Auditing are codified by the Institute of Internal Auditors. These standards, applied as appropriate to the audit objectives, are the criteria by which the office of the controller performs audits.

Compliance to the various standards include minimum continuing professional education requirements for the staff and management of the office of the controller. The Government Auditing Standards require 80 hours every two years with 24 hours in government - related courses. Certified public accountants are subject to the AICPA required 120 hours every three years (minimum 20 hours per year) and the PICPA requirement of 80 hours every two years. The Institute of Internal Auditors and the Association of Government Accountants both have similar requirements to maintain their respective certifications.