Where are Vietnam's 2026 tax audits focused? A self-assessment before the auditors arrive

The short answer

In 2026, Vietnam's tax authority moved decisively to risk-based audits. They are built on e-invoice data, bank cash flows and inter-agency information.

The Tax Department has approved an audit plan covering 11,115 businesses. Priority topics include:

• VAT refunds;

• e-invoices;

• related-party transactions;

• e-commerce;

• real estate, mining and petroleum.

The authority is also paying particular attention to businesses with multi-year losses, thin margins or sudden revenue spikes.

There is no need to wait for an audit decision before preparing. The self-assessment questions in this article help identify early the issues the tax authority is most likely to raise.

The 2026 audit landscape

According to the Tax Department, 58,076 audits were assigned for 2026 to the 34 provincial and municipal tax offices and grassroots tax units. The plan for on-site audits at taxpayers' premises covers 11,115 businesses.

In the first half of the year, more than 26,000 audits led to recommended adjustments of over VND 34,258 billion.

In the related-party and anti-transfer-pricing programme alone, 87 businesses were audited. The results:

• collections, refund reversals and penalties of VND 1,062.33 billion;

• loss reductions of VND 5,970.91 billion;

• upward adjustments to taxable income of VND 3,181.93 billion.

On average, each business audited on related-party transactions paid more than VND 12 billion.

What matters most is not the numbers but the method. The tax authority no longer selects businesses on a rotating schedule. It matches invoice data against returns and cash flows, then picks out files showing anomalies. The 2025 Law on Tax Administration also allows taxpayers to be grouped by compliance history and gives priority to remote audits on electronic data.

Eight focus areas for 2026

Area	Why it attracts attention	What the tax authority typically examines
Multi-year loss-makers and thin-margin businesses	Persistent losses despite continued or expanding operations	Intra-group costs: interest, service fees and royalties paid to related parties
Related-party transactions	Risk of profit shifting offshore	Transfer pricing documentation, interest deduction caps, substance of intra-group services
VAT refunds	Risk of refund fraud through fictitious invoices	Supply chain, genuineness of transactions, cash flows
E-invoices	Invoice trading and invoices from "ghost" companies	High-risk sellers, invoices issued at the wrong time, mismatched signing dates
E-commerce and the digital economy	Revenue that is hard to track, cross-border transactions	Platform revenue versus declarations, foreign contractor tax on overseas suppliers
Sudden revenue spikes	Unusual movements against history and industry	Revenue recognition timing, cost of sales, new customers
Real estate and capital transfers	High-value transactions prone to under-declared prices	Transfer prices and tax obligations on capital transfers
High-risk sectors	Scrap steel, gold and jewellery, construction and installation, BOT, insurance, golf, petroleum, mining	Revenue, cost of sales and input invoices specific to each sector

The Tax Department also issued Official Letter No. 1927/CT-KTr on 31 March 2026, calling for tighter management of multi-year loss-makers and thin-margin businesses. It stresses review of large expenses, related-party transactions and intra-group costs such as interest, service fees and royalties.

Ten self-assessment questions

If the answer is "yes" to three or more, the business is very likely already within the attention of the risk management system.

1. Has the business made losses for three years or more while still growing revenue or expanding investment?

2. Are its margins significantly below those of peers in the same industry?

3. Does it pay service fees, management fees, royalties or interest to its parent or related parties?

4. Did 2026 revenue rise or fall by more than 30% year on year without a clear explanation?

5. Does it file large or frequent VAT refund claims?

6. Does it hold input invoices from suppliers that have ceased operating or carry risk alerts?

7. Do revenue figures on e-invoices, VAT returns and financial statements fail to match?

8. Does it sell through e-commerce platforms or buy digital services from overseas suppliers?

9. Has it transferred capital or projects, or restructured, in the past three years?

10. Are there known errors in prior years that have not yet been amended?

When an audit decision arrives: seven principles

1. Read the decision carefully. Confirm its scope (taxes and periods), duration and audit team. The business is only obliged to provide documents within the scope of the decision.

2. Appoint a single point of contact to work with the team. Log every document provided.

3. Organise electronic files systematically: books, invoices, contracts and related-party documentation, arranged according to the team's requests.

4. Give explanations in writing, with legal references. Avoid verbal explanations on complex issues.

5. Do not sign minutes you disagree with. The business has the right to reserve its position and record its disagreement in the minutes.

6. Consider timely self-correction of clear errors. The timing of an amendment relative to the audit decision directly affects the penalty.

7. Preserve the right to complain and litigate against incorrect conclusions or decisions. Keep all communications in writing.

Illustrative case

Company G, a foreign-invested manufacturer, has made losses for five consecutive years while expanding its factory. Each year it pays its parent a royalty of 3% of revenue plus management service fees.

The file combines three risk indicators: persistent losses, related-party transactions and large intra-group costs. This is exactly the group targeted by Official Letter 1927/CT-KTr.

Before any audit decision, Company G took three steps:

• it updated its benchmarking study for profit margins;

• it built evidence of the actual benefit of each service received from the parent: reports, emails, personnel involved and outcomes;

• it reviewed the foreign contractor tax withheld on royalties.

When the tax authority arrived, most of its questions already had documented answers. The scope of adjustments was therefore significantly narrower than for businesses caught unprepared.

FAQs

Which businesses are most likely to be audited in 2026?

Businesses with multi-year losses or thin margins, related-party transactions or large VAT refund claims, and those in high-risk sectors such as real estate, e-commerce, petroleum, mining and scrap steel.

How does the tax authority select businesses for audit?

Mainly through risk management: matching e-invoice data against returns and bank cash flows, combined with grouping taxpayers by compliance history.

Should a business self-amend before an audit?

For clearly identified errors, early amendment usually reduces penalty exposure significantly. The business must still pay the tax shortfall and late-payment interest. Note that the amendment window is now 5 years.

Can a business refuse to sign the audit minutes?

The business may reserve its position, provide explanations and record its disagreement. It may also complain about or challenge enforcement decisions in court as provided by law.

Legal basis

• Law on Tax Administration No. 108/2025/QH15 and Decree No. 252/2026/ND-CP.

• Decree No. 125/2020/ND-CP, as amended by Decree No. 310/2025/ND-CP, on administrative penalties for tax and invoice violations.

• Decree No. 255/2026/ND-CP on tax administration of related-party transactions.

• Official Letter No. 1927/CT-KTr of the Tax Department dated 31 March 2026.

How W&A can help

The outcome of a tax audit is largely decided before the auditors arrive. W&A supports businesses both before and during an audit:

• Tax Health Check: risk assessment aligned with the tax authority's current priority topics, quantification of potential exposure and remediation proposals.

• Related-party transactions: updating transfer pricing documentation, benchmarking and evidence of benefit for intra-group services.

• Support throughout the audit: preparing documents, drafting written explanations and attending meetings with the audit team.

• Tax attorney services: representation in complaints, dialogue and litigation against audit conclusions and decisions.

• Proactive amendments: correcting prior-year errors within the 5-year window to minimise penalty exposure.