Dear Clients and Partners,
As we move into the second half of 2026, the regulatory landscape in Vietnam is undergoing a transformative shift. For foreign-invested enterprises (FIEs) and multinational corporations, the "business as usual" approach to tax finalization is no longer sufficient. With the full implementation of the Tax Administration Law 2025 and the aggressive enforcement of Decree 310/2025/ND-CP, tax authorities have moved from manual inspections to sophisticated, data-driven risk analytics.
In 2026, the Department of Taxation has launched a specialized audit campaign targeting specific risk profiles: specifically those with sustained losses or low profit margins despite continued expansion. At BLaw Vietnam, we have observed a recurring pattern of "preventable" errors that lead to significant back-taxes and penalties.
To help you navigate this high-stakes environment, we have identified the seven most critical mistakes businesses are making today and, more importantly, how to fix them using a "Clockwork" legal approach.
1. The "Loss-Making" Trap: Sustained Losses Without Robust Justification
One of the most significant developments in 2026 is Official Letter 1927/CT-KTr, which explicitly prioritizes enterprises reporting continuous losses for multiple years while simultaneously increasing charter capital or revenue.
The Mistake: Many FIEs assume that if they are in an "investment phase," losses are naturally accepted. However, without a robust business plan or benchmarking study to support these losses, the tax authority may deem your financial position as a "transfer pricing risk," leading to an immediate on-site audit.
The Clockwork Fix:
- Document the "Why": Prepare a comprehensive dossier explaining the economic rationale for losses (e.g., market entry costs, supply chain disruptions, or R&D investment).
- Proactive Benchmarking: Use industry data to demonstrate that your low margins are consistent with the current market cycle in Vietnam.
- Internal Link: Explore our Tax Optimization Vietnam 101 guide for a deeper look at risk profiling.
2. Invoicing Timing Errors: Falling Foul of Decree 310/2025
Effective January 16, 2026, the new penalty framework for invoicing violations has become significantly more granular: and expensive.
The Mistake: Issuing e-invoices outside the mandatory timeframe (e.g., several days after the completion of a service or the delivery of goods). Previously, this might have resulted in a minor administrative warning; under the new decree, fines can reach up to VND 70 million per batch of violations.
The Clockwork Fix:
- Automate Compliance: Integrate your ERP system with the General Department of Taxation’s database to ensure real-time invoice issuance.
- Audit Internal Workflows: Our Licensing Team recommends a weekly reconciliation between "Delivery Notes" and "Issued Invoices" to catch timing gaps before they become systemic.
3. Related-Party Gaps: The Transfer Pricing Documentation Void
Transfer pricing (TP) remains the single largest source of tax adjustments in Vietnam. In 2026, authorities are scrutinizing management fees and intercompany service charges with unprecedented rigor.
The Mistake: Paying high management or royalty fees to a parent company without "tangible evidence" of the services rendered. If you cannot prove the benefit received by the Vietnamese entity, the entire expense can be declared non-deductible.
The Clockwork Fix:
- The Three-Pillar Test: Ensure every related-party transaction meets the criteria of being (1) necessary for business, (2) priced at arm's length, and (3) supported by contemporaneous documentation (contracts, emails, logs, and reports).
- Update Local Files: Ensure your TP Local File is not just a copy of the Group Master File; it must reflect Vietnam-specific economic realities for the 2025–2026 period.
4. Mismatched Revenue Recognition: Accounting vs. VAT Obligations
The 2026 audit focus areas specifically highlight the "Revenue vs. Cost vs. Profit" relationship.
The Mistake: Recognizing revenue in your financial statements in one period but declaring the output VAT in another. This often happens with long-term construction projects or complex service contracts where "percentage of completion" is used for accounting, but "payment milestones" are used for VAT.
The Clockwork Fix:
- Consistency is Key: Align your revenue recognition policy across both your corporate governance frameworks and your tax filings.
- Contract Review: Have our Advisory Team review your contract templates to ensure that "Trigger Points" for VAT and Revenue are clearly defined and legally defensible.
5. The "IFRS vs. VAS" Blind Spot
While many multinational companies manage their global accounts using IFRS, the Vietnamese tax authority only recognizes Vietnamese Accounting Standards (VAS) for tax settlement purposes.
The Mistake: Preparing your Corporate Income Tax (CIT) finalization based on IFRS adjustments. This frequently leads to miscalculated depreciation, incorrect provisions for bad debts, and misaligned foreign exchange gain/loss treatments.
The Clockwork Fix:
- Mandatory Statutory Audit: Ensure your annual audit is completed by a Vietnam-licensed firm by March 31.
- VAS Conversion: Implement a robust "bridge" between your global reporting and VAS to ensure every tax-deductible expense is supported under local law.
6. Weak Substantiation of "Business Purpose"
In 2026, the definition of a "deductible expense" has narrowed. Authorities are no longer just looking for a valid invoice; they are looking for a clear "business purpose."
The Mistake: High marketing, travel, or entertainment expenses that lack supporting "proof of activity." For example, a business dinner without a guest list or a marketing campaign without a performance report.
The Clockwork Fix:
- Standard Operating Procedures (SOPs): Implement a "Clockwork" internal checklist for employees. No reimbursement is issued unless it is accompanied by (1) a valid VAT invoice, (2) a contract/PO, and (3) a brief summary of the business objective achieved.
- Learn more: Check out our 7 Mistakes with Tax Optimization for detailed expense classification.
7. Expat PIT and Social Insurance Negligence
With the integration of digital data between the Department of Labor and the Department of Taxation, expat compliance is now under a microscope.
The Mistake: Failing to declare global income for "Tax Residents" (expats staying >183 days) or neglecting the mandatory Social Insurance (SI) contributions for foreign employees.
The Clockwork Fix:
- Comprehensive PIT Review: Conduct a mid-year health check of your expat payroll. Ensure that "Benefits in Kind" (housing, school fees, etc.) are correctly taxed.
- Cross-Departmental Compliance: Ensure your HR team is aligned with Vietnam employment law to avoid overlapping penalties for both tax and labor violations.
The "Clockwork" Solution: How BLaw Vietnam Protects Your Business
Through the above analysis, it is clear that tax settlement in 2026 is no longer an "end-of-year" task: it is a continuous operational requirement. At BLaw Vietnam, we offer more than just advice; we provide a system of excellence.
Our Tax Settlement Advisory services include:
- Pre-Audit Health Checks: Identifying and fixing the 7 mistakes mentioned above before the tax authorities arrive.
- Transfer Pricing Defense: Crafting robust Local Files that stand up to the most aggressive scrutiny.
- Customized SOPs: Designing internal "Clockwork" systems that ensure your Juniors and Seniors never miss a deadline or a documentation requirement.
Optimize Your Tax Strategy Today
Don't wait for a notification from the Department of Taxation to realize your system has gaps. Whether you are looking for tax optimization, assistance with M&A transactions, or specialized corporate governance advice, our knowledgeable attorneys are ready to assist.
Contact BLaw Vietnam today for a confidential consultation and let us help you turn your legal compliance into a competitive advantage.
Best regards,
The BLaw Vietnam Team
Excellence. Client Focus. Knowledge.