Services provided
The primary functions performed by CPAs relate to assurance services. The most commonly performed assurance services are financial audit services where CPAs attest to the reasonableness of disclosures, the freedom from material misstatement, and the adherence to the applicable generally accepted accounting principles (GAAP) in financial statements. CPAs can also be employed within corporations (termed "the private sector") in finance or operations positions such as financial analyst, finance manager, controller, chief financial officer (CFO), or chief executive officer (CEO). These CPAs do not provide services directly to the public.

Although some CPA firms serve as business consultants, the consulting role has been under scrutiny following the Enron scandal where Arthur Andersen simultaneously provided audit and consulting services which affected their ability to maintain independence in their audit duties. This incident resulted in many accounting firms divesting in their consulting divisions, but this trend has since reversed. In audit engagements, CPAs are (and have always been) required by professional standards and Federal and State laws to maintain independence (both in fact and in appearance) from the entity for which they are conducting an attestation (audit and review) engagement. Although, most individual CPAs who work as consultants do not also work as auditors, if the CPA firm is auditing the same company that the firm also does consulting work for, then there is a conflict of interest voiding the CPA firm's independence for multiple reasons including: (1) the CPA firm would be auditing their own work or the work they suggested and (2) the CPA firm may be pressured into unduly giving a positive (unmodified) audit opinion so as to not jeopardize the consulting revenue the firm receives from client.

CPAs also have a niche within the income tax return preparation industry. Many small to mid-sized firms have both a tax and an auditing department. Along with attorneys and Enrolled Agents, CPAs may represent taxpayers in matters before the Internal Revenue Service. However, the Enrolled Agent designation is given by the IRS and does not grant someone a license to offer tax or other accounting services as licences to offer accounting services are granted by the states and the IRS has no authority to regulate tax preparers.[2]

Whether providing services directly to the public or employed by corporations or associations, CPAs can operate in virtually any area of finance including:

Assurance and attestation services
Corporate finance (merger and acquisition, initial public offerings, share and debt issuings)
Corporate governance
Estate planning
Financial accounting
Governmental accounting
Financial analysis
Financial planning
Forensic accounting (preventing, detecting, and investigating financial frauds)
Income tax
Information technology, especially as applied to accounting and auditing
Management consulting and performance management
Tax preparation and planning
Venture capital
Financial reporting
Regulatory compliance