The Public Company Accounting Oversight Board (PCAOB) was created by Congress in 2002 as part of the Sarbanes-Oxley Act (SOX) that was passed in response to a series of accounting scandals (e.g., Enron, Worldcom, etc.) to provide better oversight of the auditing industry.
The board's aim is to protect investors and other stakeholders of public companies by ensuring that the auditor of a company's financial statements has followed a set of strict guidelines.
PCAOB is overseen by the Securities and Exchange Commission. Firms that audit public companies, brokers and dealers must register with PCAOB. Registered firms are subject to inspection of the audits they have performed. PCAOB also is involved in setting standards aimed at improving the reliability of audits and may also enforce standards by imposing penalties for violations.
The AICPA is American Institute of Certified Public Accountants. It is professional association of accountants and provides guidance across a variety of accounting and audit services.
The PCAOB is responsible for monitoring CPA and CPA firms for audits of public companies, brokers and dealers.
Both entities are responsible for guidance to the audit and account field. The AICPA created standards that guide accounting professionals. The PCAOB has adopted some of the AICPA’s standards and applied them to public accounting firms.