Short answer: “Back-tax assessment” after a post-clearance audit (PCA) actually comprises 3 layers of financial obligation: (1) pay the full underpaid tax — a mandatory remedial measure; (2) late-payment interest of 0.03%/day on the late tax; (3) administrative fines — 20% of the underpaid tax when detected through PCA, or reclassification as tax evasion (01 time, up to 03 times the evaded tax) for failure to voluntarily pay in full before the inspection record. Main legal basis: Decree 169/2026/ND-CP (effective 01/7/2026, replacing Decree 128/2020) and the Tax Administration Law 108/2025/QH15 (effective 01/7/2026, replacing Law 38/2019/QH14).
1. The three financial layers of “back-tax assessment”
Layer 1 — Pay the full underpaid tax
A mandatory remedial measure under Article 10.5 of Decree 169/2026/ND-CP: “compulsory payment of the full underpaid tax; taxes exempted, reduced, refunded or not collected incorrectly into the state budget.” This obligation is unavoidable — fined or not, the shortfall must be paid in full.
Layer 2 — Late-payment interest of 0.03%/day
Charged at 0.03%/day on tax administered by customs authorities, under the Tax Administration Law 108/2025/QH15 (the specific article is being cross-checked against the original text by our legal panel — verify before applying). Interest accrues daily, so every day of delay increases the loss — pay early, stop early.
Layer 3 — Administrative fines
- Misdeclared value causing a shortfall detected through PCA → fine of 20% of the underpaid tax (Article 10.3(b) of Decree 169/2026);
- Failure to voluntarily pay the full tax before the inspection record → reclassification as tax evasion: fine of 01 time the evaded tax, +0.2 times per aggravating circumstance, up to 03 times, plus mandatory payment of the evaded tax (Article 10.4; Article 15.1(c), 15.2, 15.3 of Decree 169/2026).
Article 10 thresholds: tax difference from VND 500,000/declaration (individuals), from VND 2,000,000/declaration (organizations).
2. Basis of the assessment: the tax imposition decision
After a PCA, customs issues a tax imposition decision (Article 100 of Decree 08/2015/ND-CP; Tax Administration Law 108/2025 — article under cross-check) based on the PCA conclusion (form 04/KLKT) and the audit record. Companies should carefully compare this decision against the PCA conclusion, audit record, declaration and original vouchers to separate well-founded assessments from contestable ones (value, HS code, origin, exemption eligibility).
3. Disagree but still pay — with the right to complain
The key point under Article 37.2(o) of the Tax Administration Law 108/2025/QH15: the taxpayer must pay the tax and other amounts imposed by the tax authority’s decision. If disagreeing → still pay, while having the right to request explanations or to complain and sue; the taxpayer must provide supporting dossiers and documents.
On complaints: the limitations period is 90 days from receipt of the imposition/back-tax decision (Article 9 of the Complaint Law 02/2011/QH13 — consolidated document 28/VBHN-VPQH dated 13/3/2026; the Complaint Law’s current validity is being verified by our legal panel before this article clears publication review); first complaint to the decision issuer; if unsatisfied → second complaint to the immediate superior or file an administrative lawsuit (Article 7 of the Complaint Law).
4. Time limits: after 05 years, tax is still due
Misdeclaration causing underpaid tax / tax evasion → 05-year sanctioning limitations period (Article 5 of Decree 169/2026). After the period expires there is no fine, but the full underpaid/evaded tax plus late interest must still be paid for the 10 years preceding discovery. “Expired limitations” does not mean “no tax obligation.”
5. Enforcement for non-payment
Under Article 48 of the Tax Administration Law 108/2025, enforcement of administrative tax decisions applies where:
- Tax debt is over 90 days past the payment deadline;
- The extended payment deadline has passed and debt remains;
- The taxpayer is not operating at the registered address or is dissipating assets;
- The taxpayer fails to comply with an administrative tax sanction decision.
6. A 5-step response plan for companies
Step 1 — Review the basis: compare the imposition/back-tax decision with the PCA conclusion, audit record, declaration and original vouchers; classify assessments as well-founded vs. contestable (value, HS code, origin, exemption).
Step 2 — Pay tax and late interest by the deadline stated in the decision to stop the 0.03%/day interest and avoid enforcement. Note: paying does not waive complaint rights — the company can still complain after paying.
Step 3 — Voluntary early remediation: if still at the record-drawing stage, voluntarily pay the full tax before the record is drawn up to avoid reclassification as tax evasion (Article 10.4, Article 15.1(c) of Decree 169/2026). This step decides the scale of loss.
Step 4 — Complain: 90-day period from receipt; first complaint to the decision issuer; if unsatisfied → second complaint or administrative lawsuit.
Step 5 — Prepare complaint evidence: value-proving vouchers (contracts, invoices, L/C-TTR payment vouchers, published discount schedules), technical documents (HS code), C/O (origin); advance rulings (Article 28 of the Customs Law) are strong evidence if previously obtained.
7. The damage-control window: self-discover before the audit team arrives
The decisive nuance: the 20% fine applies when detected through PCA; if the company self-discovers and supplements more than 60 days after clearance but before any PCA decision, only 10% applies (Article 10.2(b) of Decree 169/2026). Periodic internal reviews — catching errors before the PCA team arrives — can halve the fine.
8. Company rights during the process
Under the Tax Administration Law 108/2025/QH15, companies have the right to: explanations of tax calculation and imposition; reserve opinions and explanations; complain about and sue administrative tax decisions and acts; request inspection of import/export goods; when the tax authority inspects: refuse on-site inspection at the taxpayer’s premises without an inspection decision; refuse to provide information and documents unrelated to the inspection’s contents.
Never cite Decree 128/2020 or Law 38/2019 as current basis — both expired on 01/7/2026.
Frequently asked questions
Must back-assessed tax be paid immediately?
Yes. Under Article 37.2(o) of Law 108/2025, the taxpayer must pay the imposed amount; disagreement does not suspend payment, while complaint and lawsuit rights remain.
Can the company still complain after paying?
Yes. Paying does not waive complaint rights. The complaint period is 90 days from receipt of the decision.
What is the fine for tax evasion after a PCA?
01 time the evaded tax (no aggravating circumstances), +0.2 times per aggravating circumstance, up to 03 times, plus mandatory payment of the evaded tax (Article 15 of Decree 169/2026).
Can tax still be assessed after 05 years?
After the 05-year sanctioning limitations period, no administrative fine — but the full underpaid/evaded tax plus late interest for the 10 years preceding discovery must still be paid.
How to avoid reclassification as tax evasion?
Voluntarily pay the full tax before the inspection record is drawn up (Article 10.4, Article 15.1(c) of Decree 169/2026) — the only exit from the reclassification mechanism.
Need help reviewing customs dossiers, preparing for a post-clearance audit, or handling a back-tax assessment? Reach us via the Contact page of FLAT Law Firm.
For reference only, not legal advice.
For reference only, not legal advice. Content quality-checked by the AI Legal Council; not yet reviewed by a human lawyer.