Vietnam FIE Audit Requirements: Mandatory Filing, Deadlines & Penalties (Update 2026)

All foreign-invested enterprises (FIEs) in Vietnam face mandatory independent audits regardless of size, revenue, or headcount under the Law on Independent Audit, Article 37. This absolute requirement distinguishes FIEs from domestic companies, which trigger audit obligations only above specific “large-scale” thresholds.

Effective January 1, 2026, enterprises must maintain robust internal control documentation under Circular 99/2025/TT-BTC to support audit testing per Vietnamese Standards on Auditing. Undocumented governance now elevates the risk of audit qualifications and expanded substantive testing.

Decree 90/2025/ND-CP (effective April 14, 2025) defines “large-scale enterprise” classification using criteria established for statistical reporting to the General Statistics Office. Enterprises meeting relevant thresholds face expanded reporting obligations. Non-compliance penalties reach VND 50 million, and late filing creates compounding exposure with tax penalties. This guide covers who must audit, the 90-day filing timeline, 2026 regulatory changes, and penalty schedules for Vietnam FDI compliance.

Executive Key Takeaways

• Financial Impact: All FIEs face mandatory independent audit regardless of size—budget VND 30-80M (~USD 1,200-3,200) annually for audit fees; non-compliance penalties reach VND 50M (~USD 2,000).
• Legal Compliance: 100% of foreign-invested enterprises must conduct statutory audit under the Law on Independent Audit, Article 37; non-FIEs trigger only above specific thresholds.
• Timeline: Audited financial statements must be submitted no later than the last day of the 3rd month after fiscal year-end (typically March 31 for December 31 FYE) to the Tax Authority, Department of Planning and Investment, and General Statistics Office.
• Strategic Risk: Effective January 1, 2026, enterprises must maintain robust internal control documentation under Circular 99/2025/TT-BTC—undocumented governance creates audit qualification risk.
• Regulatory Expansion: Decree 90/2025/ND-CP (effective April 14, 2025) defines “large-scale enterprise” classification using established criteria: 200+ SI employees, VND 300B (~USD 12M) revenue, VND 100B (~USD 4M) assets.

Who Must Conduct Statutory Audit in Vietnam

The audit obligation landscape in Vietnam operates on a dual-track system: absolute requirements for foreign-invested enterprises and threshold-based triggers for domestic companies.

FIE Mandatory Audit Rule

Every foreign-invested enterprise must conduct an annual statutory audit under the Law on Independent Audit, Article 37. This rule applies regardless of charter capital amount, annual revenue, or employee headcount. Whether a boutique service firm or a manufacturing complex, the obligation is identical: mandatory independent audit. The Tax Authority views the audit report not just as a filing, but as the primary validation of your deductible expenses. The regulation contains no exemptions, size thresholds, or grace periods for newly established entities.

The Tax Authority maintains a centralized database of FIE registration data linked by enterprise tax code. During annual compliance reviews, the Tax Authority’s audit report module flags enterprises registered as FIEs but lacking audit report submissions. This automated cross-referencing triggers penalty assessments and compliance notices to both the enterprise and Department of Planning and Investment (DPI). The key risk is that missing audit reports trigger immediate penalty assessments and create red flags for subsequent license renewals or investment certificate amendments.

Non-FIE Threshold Triggers (Large-Scale Enterprises)

Domestic companies trigger mandatory audit only if they meet the “Large-Scale Enterprise” definition under Decree 90/2025/ND-CP dated 14 April 2025. This requires meeting at least two of the following three criteria:

⚠️ COMPLIANCE ALERT: Decree 90/2025/ND-CP expands mandatory audit to domestic firms meeting 2/3 of these criteria (200+ SI employees, VND 300B revenue, VND 100B assets).

Audit Process, Timeline and 2026 Compliance Changes

The statutory audit process follows a structured timeline tied to fiscal year-end dates, with specific deliverables required under Vietnamese Accounting Standards (VAS).

Required Financial Statements

Audited financial statements must include four core components under VAS:

• Statement of financial position: Assets, liabilities, and equity as of fiscal year-end.
• Income statement: Revenue, expenses, and profit for the fiscal year.
• Cash flow statement: Operating, investing, and financing activities.
• Notes to financial statements: Accounting policies, contingencies, and related party transactions.

The audit opinion must reference compliance with VAS and Vietnamese Standards on Auditing. Management letter findings, while not submitted to authorities, document internal control weaknesses and become critical for addressing qualified opinion risks.

Filing Deadline and Submission Points

Audited financial statements must be filed no later than the last day of the 3rd month after the end of the fiscal year (typically March 31 for a Dec 31 FYE) under Article 44, Clause 2 of the Law on Tax Administration 38/2019/QH14. Submission requires three separate filings:

1. Tax Authority: Accompanies annual corporate income tax finalization.
2. Department of Planning and Investment (DPI): Fulfills investment certificate reporting requirements.
3. General Statistics Office (GSO): Supports national economic data compilation.

The Tax Authority submission receives priority enforcement. However, DPI cross-checks audit reports during license renewal reviews. Missing submissions create delays in certificate amendments or capital increase approvals. The key risk is that each agency operates independent penalty assessment processes.

Auditor Selection and Rotation Rules

Under Decree 90/2025/ND-CP, the mandatory rotation period for signing auditors has been extended to 5 consecutive years (previously 3 years). This allows FIEs greater continuity, provided the audit firm maintains independence. This creates a practical timeline for FIE audit planning:

• Q3 (July-September): Auditor selection and engagement letter signing.
• Q4 (October-December): Interim fieldwork and internal control testing.
• Q1 (January-March): Year-end fieldwork and draft report review.
• Q1+90 days: Final audit opinion and filing deadline.

Late auditor engagement in Q4 compresses fieldwork timelines and increases the risk of missing the 90-day filing deadline. A common compliance gap is companies waiting until January to begin auditor selection, leaving insufficient time for proper internal control documentation review.

Internal Control Documentation (Circular 99/2025/TT-BTC)

Effective January 1, 2026, Article 3 of Circular 99/2025/TT-BTC explicitly mandates that enterprises must establish and document internal governance regulations and internal control systems. This shifts internal control from a “best practice” to a statutory compliance requirement. Enterprises must ensure robust internal control documentation to support audit testing under Vietnamese Standards on Auditing. Undocumented governance elevates risks of audit qualifications and expanded substantive testing. Companies must formalize control procedures in writing, covering:

• Authorization and approval hierarchies for financial transactions.
• Segregation of duties in accounting and treasury functions.
• Physical and system access controls for assets and records.
• Monitoring and review procedures for financial reporting.

⚠️ COMPLIANCE ALERT: Effective January 1, 2026, undocumented internal controls create compliance risk under Circular 99/2025/TT-BTC and Vietnamese Standards on Auditing.

Risks and Penalties

Non-compliance with audit requirements triggers financial penalties and creates cascading compliance risks across multiple regulatory agencies.

Penalty Schedule

⚠️ RISK ALERT: Penalties exceed the VND 20M administrative threshold, creating a permanent compliance record.

Tax Authority enforcement varies by province. Based on audit coordination experience, Ho Chi Minh City Tax Department typically issues automated penalty notices at day 91 post-deadline, while Hanoi Tax Department often contacts enterprises informally for 30-day rectification before formal penalty assessment. However, this provincial variation is discretionary—the legal deadline remains 90 days nationwide. 

The key risk is that late audit filing compounds with late corporate income tax finalization penalties, creating combined exposure exceeding VND 70 million (~USD 2,800) for a single fiscal year violation.

Common Audit Triggers and Violations

Based on recent trends, three scenarios create the highest penalty exposure:

1. Late auditor engagement: Selecting auditors in Q1 leaves insufficient time for fieldwork, pushing final audit opinion past the 90-day deadline.
2. Incomplete VAS disclosures: Missing related party transaction notes or contingent liability disclosures result in qualified audit opinions, which the Tax Authority scrutinizes during transfer pricing reviews.
3. Missing management letter: While not submitted to authorities, the absence of management letter documentation prevents companies from addressing internal control weaknesses before they escalate to audit opinion qualifications.

Qualified Opinion Consequences

Qualified, adverse, or disclaimer audit opinions create business impacts beyond regulatory penalties:

• Banking relationships: Loan covenants typically require unqualified audit opinions; qualifications trigger technical defaults.
• License renewals: DPI reviews audit opinions during investment certificate renewals; qualified opinions create delays.
• Parent company reporting: Foreign parent companies consolidating Vietnam subsidiary results face audit qualification issues in group financial statements.

Conclusion

Foreign-invested enterprises face 100% mandatory audit under the Law on Independent Audit, Article 37 regardless of size, with audited financial statements due by the last day of the third month after fiscal year-end (typically March 31) under Article 44 of the Law on Tax Administration 38/2019/QH14. 

Effective January 1, 2026, enterprises must maintain robust internal control documentation under Circular 99/2025/TT-BTC, Article 3, which requires enterprises to develop internal governance regulations supporting audit testing. Decree 90/2025/ND-CP defines “large-scale enterprise” classification using criteria aligned with the General Statistics Office. 

Non-compliance penalties under Decree 41/2018/ND-CP can reach VND 50 million for failure to conduct required audits, with late filing penalties of VND 5–20 million compounding tax finalization exposure.

Indochina Link Vietnam provides end-to-end audit coordination—from auditor selection to compliant filing across the Tax Authority, DPI, and GSO.

Proactive Governance: Don’t wait for the management letter. Indochina Link Vietnam’s pre-audit assessment aligns your internal controls with Circular 99/2025/TT-BTC standards before the fieldwork begins.