AU-C Section 700 is the AICPA auditing standard that governs how an independent auditor forms an opinion on a set of financial statements and what the resulting report has to say. It applies to audits of non-issuers in the United States, meaning private companies and other entities that fall outside PCAOB oversight.1AICPA & CIMA. AICPA Statements on Auditing Standards – Currently Effective SAS No. 134 rewrote the reporting format for periods ending after December 15, 2021, moving the opinion to the top of the report and expanding what the auditor has to say about management’s role and their own.
What AU-C 700 Covers
The standard sits within the AICPA’s clarified Statements on Auditing Standards and governs one specific output: the report the auditor attaches to a client’s financial statements. It tells the auditor when a clean opinion is warranted, what heading and paragraph structure the report must follow, and what language identifies the framework used, the entity audited, and the periods covered.
Public companies do not use AU-C 700. Their auditors report under PCAOB standards, which sit in a parallel system with its own vocabulary. If a report you are reading references “auditing standards generally accepted in the United States of America,” you are inside AU-C 700; if it references “the standards of the PCAOB,” you are not.
When an Unmodified Opinion Is Appropriate
An unmodified opinion, sometimes called a clean opinion, is only proper when the auditor has gathered enough high-quality evidence to conclude that the financial statements are free from material misstatement. “Sufficient” speaks to how much evidence; “appropriate” speaks to its relevance and reliability. Both boxes have to be checked.
The financial statements themselves must be prepared under an applicable reporting framework, most often U.S. GAAP. A complete set generally includes the balance sheet, income statement, statement of cash flows, statement of changes in equity, and the accompanying notes.
Immaterial misstatements do not block a clean opinion. Materiality is set during planning against a benchmark such as pretax income, revenue, or total assets, and it is a judgment informed by both dollar amounts and qualitative factors such as who is affected and what the misstatement concerns. The auditor also evaluates whether the accounting policies make sense for the industry and whether disclosures let a reader understand the significant transactions. If those conditions are met and no circumstance calls for a modification, the auditor issues the unmodified opinion.
What Belongs in the Report
SAS No. 134 fixed the order of the report, and that order carries information on its own. The most important content sits at the top.
Title and Addressee
The title includes the word “Independent,” signaling that the auditor is not part of management. The addressee is typically the board of directors, the stockholders, or whoever engaged the auditor.
Opinion
The opinion paragraph now appears first, immediately after the title and addressee. It names the entity, identifies the financial statements audited, states the periods or dates covered, names the reporting framework, and concludes that the statements “present fairly, in all material respects” the entity’s financial position and results. Before SAS 134, this paragraph appeared at the end.
Basis for Opinion
Directly below the opinion, the Basis for Opinion section confirms that the audit followed U.S. GAAS, states that the auditor is independent, affirms that ethical responsibilities were met, and asserts that the evidence obtained was sufficient and appropriate. Under prior guidance this section was only required for modified opinions; SAS 134 made it mandatory in every report.1AICPA & CIMA. AICPA Statements on Auditing Standards – Currently Effective
Responsibilities of Management
This section states that management is responsible for preparing and fairly presenting the financial statements, for designing and maintaining the internal controls that keep them free from material misstatement, and for evaluating whether conditions raise substantial doubt about the entity’s ability to continue as a going concern. SAS 134 sharpened the going concern language here.
Responsibilities of the Auditor
The auditor’s section describes what the audit involves: obtaining reasonable assurance, identifying risks of material misstatement from fraud or error, testing internal controls relevant to the audit, evaluating accounting policies and estimates, and reaching a conclusion on going concern. SAS 134 expanded this section to define reasonable assurance explicitly and to emphasize professional judgment and skepticism. It also notes that the auditor communicates with those charged with governance about scope, timing, significant findings, and certain control deficiencies.
Signature, Location, and Date
The report closes with the firm’s signature (firm name or engagement partner, depending on policy), the city and state of issuance, and the report date. That date cannot precede the day the auditor obtained sufficient appropriate evidence, including management’s acknowledgment of responsibility for the final statements.
When the Opinion Has to Be Modified
If the financial statements are not fairly presented, or if the auditor could not gather enough evidence, the opinion changes. Which of the three modified opinions applies depends on how severe the issue is and how widely it affects the statements.
- Qualified opinion. A material misstatement or evidence limitation exists in a specific area, but the issue is not pervasive. The report says the statements are fair “except for” that item.
- Adverse opinion. Misstatements are both material and pervasive, distorting the statements broadly enough that an “except for” caveat would understate the problem. The auditor states that the statements do not present fairly.2Public Company Accounting Oversight Board. AS 3105 – Departures from Unqualified Opinions and Other Reporting Circumstances
- Disclaimer of opinion. Scope restrictions kept the auditor from gathering sufficient evidence, and those restrictions are pervasive enough that no opinion can be formed at all.2Public Company Accounting Oversight Board. AS 3105 – Departures from Unqualified Opinions and Other Reporting Circumstances
Pervasiveness is the dividing line. An inventory valuation problem confined to one account may warrant a qualified opinion. A misstatement that ripples through revenue, assets, and equity at once crosses into adverse territory. Scope problems escalate the same way, from qualified toward disclaimer depending on how much of the financial picture the auditor could not see.
Going Concern Under an Unmodified Report
A clean opinion is still possible when substantial doubt exists about the entity’s ability to continue for the next twelve months. The reasoning is narrow: if management adequately discloses the uncertainty, the statements themselves are fairly presented. The problem lies in the business, not in the reporting.
When that doubt exists, the auditor adds a separate section headed something like “Substantial Doubt About the Entity’s Ability to Continue as a Going Concern,” placed immediately after the opinion and Basis for Opinion. The paragraph references the disclosure note in the financial statements and describes the conditions that raise the doubt.3Public Company Accounting Oversight Board. Consideration of an Entity’s Ability to Continue as a Going Concern Management performs the primary going concern evaluation; the auditor assesses whether that evaluation is reasonable and whether the disclosures are adequate.4KPMG. Going Concern Handbook If the risk is buried in a footnote that no reader would find, the auditor may need to modify the opinion rather than simply add the going concern section.
Key Audit Matters and When They Apply
AU-C Section 701 introduces Key Audit Matters (KAMs), which describe the issues the auditor judged most significant during the current-period audit. Typical examples include complex revenue recognition, estimates with wide possible ranges, and areas where the accounting rules leave real interpretive room.
KAMs are not standard for most private company audits. AU-C 701 applies when the entity is listed on a stock exchange, when a law or regulation requires it, or when the auditor and client agree to include them voluntarily. Voluntary inclusion sometimes happens at the request of a lender, investor, or regulator. A KAM section never substitutes for a modified opinion; if an issue is serious enough to change the opinion, it belongs in the opinion itself.
Public company reports use a related concept called Critical Audit Matters (CAMs), defined under PCAOB AS 3101 and mandatory for large accelerated and accelerated filers. Same idea, different rulebook.
Prior-Year Statements and a New Auditor
Most companies present at least two years of financial statements side by side. When the same firm audited both years, the auditor updates the prior-year opinion as part of the current engagement, and any change from the earlier opinion (for example, a qualification that has since been resolved) is explained.
When a different firm audited the prior year, two paths are available. The predecessor auditor can reissue the original report after appropriate procedures, or the successor auditor’s report can reference the predecessor by naming the firm, the opinion issued, and the date of that report. Either way, the successor does not take responsibility for the predecessor’s opinion. If the prior-year statements were not audited at all, the current report must say so and disclaim any opinion on those numbers.
What a Clean Opinion Does Not Promise
An unmodified opinion is the highest level of assurance an auditor gives, but the standard itself uses the word “reasonable,” not absolute. Auditors test samples of transactions rather than every entry, so a material misstatement could sit in the untested population. Financial statements also rely on management estimates, and the auditor evaluates whether those estimates fall within a reasonable range rather than whether they will prove exactly right.
Fraud is a particular limit. The audit is designed to detect material misstatements whether caused by error or fraud, but it is not a forensic investigation, and collusion, forged documents, or deliberate override of controls can defeat procedures built to catch problems. A clean opinion should not be read as a fraud-free certification. It also says nothing about the future: a company can receive an unmodified opinion and file for bankruptcy the next quarter if circumstances shift. What the opinion tells you is that, on the evidence available at the report date, the financial statements are a reliable starting point for economic decisions.
AU-C 700 vs. PCAOB Reporting
The AU-C 700 report and the PCAOB AS 3101 report look similar. Both open with the opinion, follow with a Basis for Opinion section, and describe the responsibilities of management and the auditor. The most visible difference is at the significant-issues layer: KAMs under AU-C 701 are generally voluntary for non-issuers, while CAMs under AS 3101 are required for large accelerated and accelerated filers. The independence framing also differs in source, with AU-C reports referencing the AICPA’s Code of Professional Conduct and PCAOB reports referencing the Board’s own rules and SEC regulations. The one-phrase test in the Basis for Opinion section tells you which framework you are reading.