Section 201 of the Sarbanes-Oxley Act of 2002 forbids an audit firm to sell its audit clients a list of other services. Among them are “financial information systems design and implementation,” “actuarial services,” “internal audit outsourcing services,” and “legal services and expert services unrelated to the audit.”
Under Section 202, other services, including tax work, “must be preapproved by the issuer’s audit committee.” The law followed the collapse of Enron, whose auditor, Arthur Andersen, had done both audit and non-audit work for the company.