Quick answer: The global minimum tax in Vietnam (QDMTT — the qualified domestic minimum top-up tax) is not just an extra tax bill — it is an entirely new compliance system with significant costs even when a company owes zero top-up tax. Scope: constituent entities in Vietnam of multinational groups with consolidated revenue of EUR 750 million or more (in at least 2 of the last 4 fiscal years). Compliance costs fall into four groups: accounting data systems, registration and filing, professional advisory, and penalty risk. Decree 236/2025/ND-CP (issued 29/08/2025, effective 15/10/2025, applicable from fiscal year 2024) details all these obligations.
Applicable legal bases
The framework below is in force as of 20 October 2026 and directly governs this article:
- Resolution 107/2023/QH15 (effective 01/01/2024) — application of top-up corporate income tax under the global anti-base erosion rules (15% global minimum tax).
- Decree 236/2025/ND-CP (issued 29/08/2025; effective 15/10/2025; applicable from fiscal year 2024) — detailed rules: scope, QDMTT and IIR application principles, tax registration, filing, and payment to the central budget.
- Law on Tax Administration 108/2025/QH15 (effective 01/07/2026, replacing Law 38/2019/QH14) — registration, filing, payment obligations and sanctions.
In-depth analysis
Many FDI companies still think of QDMTT as simple arithmetic: “effective rate below 15%, pay the difference.” In reality, the tax computation is the tip of the iceberg. To arrive at the GloBE effective tax rate (ETR), a company must rebuild its financial data under a rulebook entirely different from Vietnamese accounting standards: GloBE income, adjusted covered taxes, substance-based income exclusion. Each metric has its own definition, and one wrong metric can skew the whole ETR — causing underpayment (penalized) or overpayment (money lost).
Vietnam’s distinctive point: the QDMTT is designed to keep the right to collect top-up tax in Vietnam rather than letting another country collect under IIR/UTPR. So even where the group already has a top-up payment mechanism at the parent level, the Vietnamese entity must still fully perform its QDMTT registration and filing obligations in Vietnam. There is no “the group already paid abroad, so the Vietnamese subsidiary is excused from procedures.”
The four compliance cost groups
Group 1 — Data and accounting systems: the costliest and hardest to reverse. Companies must extract data from ERP systems under GloBE metrics, reconcile VAS accounting figures with GloBE tax figures, and keep an audit trail for every adjustment. For companies without an integrated ERP, deploying a GloBE reporting module or outsourcing data processing is a major first-year investment.
Group 2 — Registration and filing: the designated filing constituent entity must submit the tax registration dossier no later than 90 days after the fiscal year-end (for FY2024 ending on or before 30/06/2025, the deadline is 90 days from Decree 236’s effective date); notify the appointment of the filing entity within 30 days of fiscal year-end; and the QDMTT filing package includes the information return in the prescribed form. Top-up tax is paid to the central budget (not the local budget like ordinary CIT).
Group 3 — Professional advisory: the GloBE rules run to hundreds of pages of OECD technical guidance plus Vietnam’s detailed regulations — most FDI companies need international tax advisors (Big4 or specialist firms) for at least the first 1–2 years to establish the methodology before they can run it themselves. Advisory fees for a group with multiple Vietnamese constituent entities are far from trivial.
Group 4 — Penalty risk and opportunity cost: misfiling that understates tax is penalized under the Law on Tax Administration; but more dangerous is the opportunity cost of incentives — when the real ETR is pushed to a 15% floor, the value of domestic CIT incentives (holidays, reductions) is partly “neutralized,” changing the entire after-tax investment equation the company computed when choosing Vietnam.
Timelines that must not slip
Decree 236/2025 applies from fiscal year 2024 — obligations arose even before the guiding decree was issued (15/10/2025). This is the biggest pressure point: companies must retroactively prepare 2024 data while the detailed rules are brand new. The transitional period offers penalty relief mechanisms (CbCR-based safe harbors, relief for late notification/registration within limits), but safe harbors are temporary and conditional — not an indefinite “penalty-free pass.” Companies need a compliance roadmap with milestones: finalize 2024–2025 GloBE data, file tax registration within the 90-day deadline, and build a sustainable periodic filing process from FY2026 onward.
Common risks and how to prevent them
- Assuming “no top-up tax means nothing to do”: wrong — QDMTT registration and filing obligations exist independently of whether top-up tax is payable.
- Expecting the group to pay abroad: Vietnam’s QDMTT requires full performance in Vietnam; procedures are not excused because tax was paid elsewhere.
- Leaving GloBE data until the deadline looms: retrofitting 2024 data under time pressure invites errors — start now.
- Ignoring the impact on the incentive equation: remodel project after-tax returns with a 15% ETR floor — domestic incentives may lose part of their value.
Frequently asked questions
1. Is my company in QDMTT scope?
If it is a Vietnamese constituent entity of a multinational group with consolidated revenue of EUR 750 million or more in at least 2 of the last 4 fiscal years, it is in scope — regardless of domestic CIT incentives it enjoys.
2. If no top-up tax is payable, must we still file?
Yes. Tax registration, notification and QDMTT filing obligations stand alone — you must evidence through the filing that the ETR meets the standard before there is “nothing extra to pay.”
3. Where is QDMTT top-up tax paid?
To the central budget under Decree 236/2025 — unlike ordinary CIT (local budget of the head-office locality).
4. FY2024 has passed — how to handle it?
Decree 236/2025 applies from FY2024 — companies must retroactively prepare data and perform obligations for 2024. The transitional period offers conditional penalty relief, but not relief from the obligations themselves.
Key takeaway for investors
QDMTT is not a simple extra tax line — it is a compliance system with significant data, filing and advisory costs, arising even when no top-up tax is due. FDI companies in the EUR 750 million scope should start now: designate the filing entity, build GloBE data (including 2024 retrospectively), and remodel investment returns with a 15% minimum effective rate.
This article has been quality-reviewed by the FLAW AI Legal Council This content is legal reference only and does not replace counsel for a specific case.
