Circular No. 04/2026/TT-KTNN promulgating the National Audit Standards System

CIRCULAR

ISSUING THE NATIONAL AUDIT STANDARDS SYSTEM

Pursuant to Law on State Audit No. 81/2015/QH13 amended and supplemented by Law No. 55/2019/QH14;

Pursuant to Law on Issuance of Legal Normative Documents No. 64/2025/QH15 amended and supplemented by Law No. 87/2025/QH15;

At the proposal of the Director of the Department of Standards and Quality Control of Audits;

The Chief State Auditor issues this Circular to promulgate the National Audit Standards System.

Article 1. Attached hereto is the National Audit Standards System (NAS) comprising: A list of terms and 43 specific national audit standards with their respective numbers and titles as follows:

1. NAS 100 - Basic Principles for State Audit Activities

2. NAS 130 - Code of Professional Ethics

3. NAS 140 - Quality Control for Audits

4. NAS 150 - Competence of State Auditors

5. NAS 200 - Principles of Financial Audit

6. NAS 300 - Principles of Operational Audit

7. NAS 400 - Principles of Compliance Audit

8. NAS 2200 - Overall Objectives and Requirements for State Auditors Conducting Financial Audits According to National Audit Standards

9. NAS 2220 - Quality Control for Financial Audits

10. NAS 2230 - Audit Documentation for Financial Audits

11. NAS 2240 - Responsibilities of State Auditors Regarding Fraud in Financial Audits

12. NAS 2250 - Assessing Compliance with Laws and Regulations in Financial Audits

13. NAS 2260 - Communicating Issues with Audited Units During Financial Audits

14. NAS 2300 - Planning Financial Audits

15. NAS 2315 - Identifying and Evaluating Material Misstatement Risks in Financial Audits

16. NAS 2320 - Determining and Applying Materiality in Financial Audits

17. NAS 2330 - Actions Taken by State Auditors Regarding Identified Risks in Financial Audits

18. NAS 2402 - Factors to Consider When Auditing Entities Using External Services in Financial Audits

19. NAS 2450 - Evaluating Errors Discovered During Financial Audits

20. NAS 2500 - Audit Evidence in Financial Audits

21. NAS 2505 - Confirmation from Third Parties in Financial Audits

22. NAS 2510 - Opening Balance Audit in Financial Audits

23. NAS 2520 - Analytical Procedures in Financial Audits

24. NAS 2530 - Sampling in Financial Audits

25. NAS 2540 - Auditing Accounting Estimates in Financial Audits

26. NAS 2550 - Related Parties in Financial Audits

27. NAS 2560 - Subsequent Events After the Reporting Period End in Financial Audits

28. NAS 2570 - Continuous Operations Audit in Financial Audits

29. NAS 2580 - Written Representations in Financial Audits

30. NAS 2600 - Considerations When Auditing Consolidated Financial Statements and Combined Financial Statements

31. NAS 2610 - Utilizing Internal Auditors' Work in Financial Audits

32. NAS 2620 - Utilizing Experts' Work in Financial Audits

33. NAS 2700 - Forming and Reporting an Audit Opinion in Financial Audits

34. NAS 2701 - Reporting Significant Audit Matters in the Audit Report

35. NAS 2705 - Non-Unqualified Opinions in Financial Audit Reports

36. NAS 2706 - Emphasis-of-Matter Paragraphs and Other Matter Paragraphs in Financial Audit Reports

37. NAS 2710 - Comparative Information - Corresponding Data and Comparative Financial Statements

38. NAS 2720 - Responsibilities of State Auditors for Other Information in Documents Containing Audited Financial Statements

39. NAS 2800 - Considerations When Auditing Financial Statements Prepared Under Special Purpose Frameworks

40. NAS 2805 - Considerations When Auditing Separate Financial Statements and Specific Elements, Accounts, or Items of Financial Statements

41. NAS 2810 - Expressing an Opinion on Condensed Financial Statements

42. NAS 3000 - Operational Audit Standards

43. NAS 4000 - Compliance Audit Standards

Article 2. This Circular shall take effect from March 30, 2026, and replace Decision No. 08/2024/QĐ-KTNN dated November 15, 2024, issued by the State Audit Office on the System of State Audit Standards.

Article 3. The heads of the units under the State Audit Agency, the State Audit Teams, members of the State Audit Teams, and related organizations and individuals are responsible for implementing this Circular./.

(Attached to Circular No. 04/2026/TT-KTNN dated February 10, 2026, issued by the State Auditor General)

This list of terms applies to all State Audit Standards (SAS) within the SAS System; specific terms applicable to each SAS are defined in the Terminology Explanation section of each SAS. Terms in the SAS System are understood as follows:

This list of terms applies to all State Audit Standards (SAS) within the System of SAS; specific terms applicable to each SAS are defined in the Term Explanation section of each SAS. Terms within the System of SAS are understood as follows:

01. Three parties involved: Audits involving at least three different parties: the State Audit Agency, the entity responsible, and the user of the audit report. The relationship between these parties is specified in the Law on State Audit and relevant legal documents.

(i) State Audit Agency: An agency established by the National Assembly, operating independently and only adhering to the law, conducting audits on the management and use of public financial resources and assets. The responsibilities of the State Audit Agency and state auditors are stipulated in the Law on State Audit, relevant legal documents, and regulations of the State Audit Agency;

(ii) Entity responsible: Entities being audited; agencies, organizations, and individuals responsible for issues related to the audited entity, managing the audited entity, or implementing audit recommendations related to it. These entities' responsibilities are carried out according to the law and regulations.

02. Financial statements: Financial statements are a system of economic and financial information prepared and presented in accordance with a framework. Financial statements usually mean a complete set of financial statements for general purposes, including relevant disclosures. Relevant disclosures typically include summaries of significant accounting policies and other disclosures. The provisions of the framework for preparation and presentation of financial statements will determine the format, structure, and content of financial statements and components of a complete set of financial statements.

02. Financial statements: Financial statements are a system of economic and financial information prepared and presented within a prescribed framework. Financial statements usually mean a complete set of financial statements for general purposes, including relevant disclosures. Relevant disclosures typically include summaries of significant accounting policies and other explanatory information. The provisions within the framework for preparing and presenting financial statements will determine the presentation, structure, and content of financial statements and components of a complete set of financial statements.

04. Financial statements for special purposes: Financial statements prepared and presented in accordance with the framework for preparation and presentation of financial statements for special purposes such as: reports on receipts and expenditures based on cash accounting that an organization may have to prepare upon request of regulatory authorities; financial situation reports requested by authorities, organizations, or sponsors; financial situation reports requested specifically by regulatory authorities, legislative bodies, or other entities performing supervisory functions; or financial situation reports in accordance with the provisions of an agreement...

04. Financial statements for special purposes: Financial statements prepared and presented within a framework for preparing and presenting financial statements for special purposes such as: reports on receipts and expenditures based on cash accounting that an organization may be required to prepare at the request of regulatory authorities; financial situation reports requested by authorities, organizations, or sponsors; financial situation reports requested specifically by regulatory authorities, legislative bodies, or other supervisory parties; or financial situation reports pursuant to the provisions of an agreement...

05. Separate financial statements or specific elements of a financial statement: A separate financial statement or a specific element of a financial statement including relevant disclosures. Relevant disclosures typically include summaries of significant accounting policies and other explanatory information related to the separate financial statement or element of a financial statement.

06. Audit evidence: Documents and information collected by state auditors related to the audit serving as the basis for evaluation, confirmation, and audit recommendations. Audit evidence includes documents and information contained in accounting records, including financial statements, and other relevant documents and information.

08. Limited assurance: Procedures performed in an audit with limited assurance are generally more limited than those required to achieve reasonable assurance. However, according to the professional judgment of the state auditor, limited assurance has some value to the users of the audit report.

08. Limited assurance: Audit procedures performed in an audit with limited assurance are generally less extensive than those necessary to achieve reasonable assurance. However, according to the professional judgment of state auditors, limited assurance has some value to the users of the audit report.

09. Written explanation: Written explanations provided by the audited entity to state auditors to confirm certain issues or support other audit evidence. In this context, written explanations do not include financial statements, the bases of financial statements, or accounting books and vouchers.

10. Non-compliance behavior: Actions of omission or violation, intentional or unintentional, carried out by the entity or its leadership, individuals working for the entity or under its direction, contrary to the law and current regulations. Non-compliance behavior does not include personal matters unrelated to the entity's operations.

11. Professional skepticism: A persistent attitude of doubt and caution towards specific situations that may indicate errors due to mistakes or fraud and careful consideration of audit evidence. Situations that may raise suspicion include:

(ii) Information leading to suspicion about the reliability of documents and interview results used as audit evidence;

(iii) Events that may be signs of fraud;

(iv) Situations requiring additional audit procedures beyond those required by audit standards.

12. Audit file: A collection of audit documents gathered, classified, used, or working papers prepared by the state auditor based on collected data and stored in a specific order as evidence for a specific audit.

12. Audit file: A collection of audit documents gathered, classified, and used by state auditors, or working papers prepared by state auditors based on collected data and stored in a systematic manner as evidence for a specific audit.

13. Framework for preparing and presenting financial statements for general purposes: A framework designed to meet the information needs of multiple common users. The framework for preparing and presenting financial statements may be a fair presentation framework or a compliance framework.

(i) Fair presentation framework refers to the framework for preparing and presenting financial statements that requires adherence to its provisions and: (a) Recognizes clearly that, to achieve fair presentation of financial statements, the leadership of the audited entity may need to disclose more than the specific requirements of the framework or (b) Recognizes clearly that, the leadership of the audited entity may deviate from the framework's requirements to achieve fair presentation of financial statements reasonably. Such cases are considered necessary only in very rare circumstances;

(ii) Compliance framework refers to the framework for preparing and presenting financial statements that requires adherence to its provisions without including recognition of points (a) or (b) above.

14. Framework for the preparation and presentation of financial reports for specific purposes: Is a framework established to meet the specific financial information needs of certain entities.

15. Framework for preparing and presenting financial information: Requirements or rules that must be followed when preparing and presenting individual financial statements; elements, accounts, or items of financial statements presented according to the framework for preparing and presenting financial statements (complete set of financial statements); financial statements prepared and presented for special purposes; or summary financial statements.

16. Operational audit: An audit to evaluate the economy, efficiency, and effectiveness in the management and use of public financial resources and assets. An operational audit focuses on examining whether programs, projects, activities, or funds are operated or implemented in accordance with principles of economy, efficiency, and effectiveness, and whether improvements are needed. Accordingly, state auditors compare actual performance against appropriate criteria; analyze causes of deviations from these criteria as well as other issues to assess economy, efficiency, effectiveness, and make recommendations for improvement.

17. Financial audit: An audit to evaluate and verify the truthfulness and fairness of financial statements or financial information of the audited entity. A financial audit focuses on determining whether the financial statements or financial information of the entity are presented in accordance with the framework for preparing and presenting financial statements and other relevant current regulations. This is achieved through the collection of sufficient appropriate audit evidence allowing state auditors to express an opinion on whether there are material misstatements due to fraud or error in the financial information, considering significant aspects.

18. Compliance audit: Is an audit to evaluate and confirm compliance with laws, internal regulations, and rules that the audited entity must follow. A compliance audit is conducted by assessing the compliance of activities, transactions, and information based on significant aspects according to applicable provisions for the audited entity. These provisions are determined as audit criteria such as legal normative documents, regulations, rules, systems, policies that the audited entity must implement. When legal normative documents and regulations are incomplete or lack guidance documents, a compliance audit may check compliance with general principles of operational management or accepted good practices that the entity must follow.

19. State auditor: Is a civil servant appointed by the National Audit Office to the state auditor rank to perform auditing tasks; in some cases, it can be understood as a member of the audit team or audit group.

20. Auditee's leadership: Includes the head of the unit or person in charge of the unit and individuals authorized by the head or person in charge of the unit, Management Board, Management Council, Board of Directors, Board of Members, Board of Directors.

21. Date of audit report issuance: Is the date when the State Audit Office issues and records on the audit report; the date of issuance of the audit report shall not precede the date when the state auditor has collected sufficient appropriate audit evidence.

22. Scope of audit: Is the spatial, temporal, and scale limits of the audit related to the audit subject. The scope of audit is usually determined simultaneously with the audit objectives and serves as a specific elaboration of these objectives.

23. Laws and regulations: Are legal normative documents issued by competent authorities and other relevant regulations (including international regulations) that the audited entity must comply with.

24. Audit documentation: Are records stored on paper, film, electronic media, and other means prescribed by current laws regarding completed audit procedures, collected audit evidence, evaluations by state auditors, and levels of authority within the State Audit Office.

25. Accounting documents: Are original records and accompanying vouchers such as checks, electronic fund transfer vouchers; invoices; contracts; ledgers and subsidiary ledgers, daily journal entries and adjustments for financial statements not reflected in daily journal entries and documents such as cost allocation schedules, calculation sheets, reconciliations, and disclosures.

26. Financial information: Is individual financial reports; certain elements, accounts, or items of financial reports presented in accordance with the framework for preparation and presentation of financial reports (full financial reports); financial reports prepared and presented for special purposes; or summarized financial reports.

27. Sufficiency of audit evidence: Is a standard for evaluating the quantity of audit evidence. The amount of audit evidence to be collected is influenced by the state auditor's assessment of the risk of material misstatement and the quality of each piece of audit evidence.

28. Appropriateness of audit evidence: Is a standard for evaluating the quality of audit evidence. Audit evidence must ensure appropriateness and reliability to support the state auditor in making assessments forming the basis of the audit opinion.

29. Professional judgment: Is the application of suitable skills, knowledge, and experience in fields such as finance, accounting, auditing, accounting standards, auditing standards... and professional ethics, helping state auditors make decisions appropriate to the specific circumstances of the audit.