What is the deadline for annual corporate income tax (CIT) finalization? The short answer: no later than the last day of the 3rd month following the fiscal year-end — i.e. 31 March for companies whose fiscal year follows the calendar year. But 2026 brings a twist: the tax-administration framework has shifted from Law 38/2019 to the Law on Tax Administration 108/2025/QH15 and Decree 252/2026/ND-CP (both effective 1 July 2026) — right in the season when companies finalize for fiscal year 2025. This article clarifies the 31 March deadline, the 2025→2026 transition, special cases and late-filing sanctions.
1. The 31 March deadline and the new legal basis
Under the Law on Tax Administration 108/2025/QH15 (replacing Law 38/2019/QH14) and Decree 252/2026/ND-CP dated 30 June 2026 (effective 1 July 2026), the annual CIT finalization dossier is due no later than the last day of the 3rd month after the fiscal year-end. For a calendar fiscal year (1 January–31 December), the deadline is 31 March of the following year.
Do NOT cite Law 38/2019/QH14 as current authority — it has been replaced. Also distinguish Law 108/2025/QH15 (Law on Tax Administration) from other instruments bearing similar numbers in different fields.
2. The 2025→2026 transition: the most confusing point
The peculiarity of this cycle: finalization for fiscal year 2025 (due 31 March 2026) still takes place while Law 38/2019 remains effective through 30 June 2026, whereas finalization for fiscal year 2026 (due 31 March 2027) falls entirely under Law 108/2025 + Decree 252/2026. Companies should:
- Identify the correct governing text for each finalization period when checking procedures and forms;
- Note any transitional provisions in Decree 252/2026 for dossiers filed before 1 July 2026;
- Not mechanically apply old guidance (from the Law 38/2019 era) to the new finalization period.
3. Special cases
- Dissolution, bankruptcy, reorganization: finalization is due within 45 days of the dissolution/bankruptcy/reorganization decision (under Decree 252/2026) — much shorter than the usual 31 March;
- Force-majeure extensions: natural disasters, fires, unexpected accidents… may qualify for extended filing deadlines as prescribed;
- Deadline falling on a holiday: the general principle applies — the deadline rolls to the next working day;
- Loss-making companies must still finalize: the finalization duty applies whether the company makes a profit or a loss — under the Law on CIT 67/2025/QH15 (effective 1 October 2025). Finalizing at a loss establishes the basis for loss carry-forward.
4. How to finalize: where to file, what the dossier contains
- Filing channel: via the tax authority public-service portal (dichvucong.gdt.gov.vn) with a digital signature, combined with level-2 electronic identification as currently prescribed;
- Dossier: the annual CIT finalization return, annual financial statements, and accompanying schedules (tax incentives, loss carry-forward, related-party transactions… as applicable);
- Tax payment: any balance of tax due after finalization is payable by the same deadline as the dossier.
5. Sanctions for late filing and late payment
Late finalization dossiers attract administrative sanctions under Decree 125/2020/ND-CP (as amended by Decree 310/2025/ND-CP) — penalties escalating with the days of delay, plus possible tax assessment in fraud cases. Late tax payments accrue late-payment interest daily. This article states no specific figures — companies should verify Decree 125/2020 (as amended by Decree 310/2025) directly, as penalty levels may be adjusted.
Frequently asked questions
What is the annual CIT finalization deadline?
No later than the last day of the 3rd month after the fiscal year-end — 31 March for calendar fiscal years (Law 108/2025 + Decree 252/2026).
Does Law 38/2019 still apply?
No. It was replaced by the Law on Tax Administration 108/2025/QH15 (effective 1 July 2026); do not cite 38/2019 as current authority.
When must a dissolving company finalize?
Within 45 days of the dissolution/bankruptcy/reorganization decision.
Must a loss-making company finalize?
Yes. The duty applies whether profitable or not (Law on CIT 67/2025); finalizing at a loss grounds loss carry-forward.
Sources
- Law on Tax Administration 108/2025/QH15 (replacing Law 38/2019/QH14; effective 1 July 2026);
- Decree 252/2026/ND-CP dated 30 June 2026 (effective 1 July 2026): annual finalization deadline; 45 days for dissolution/reorganization;
- Law on CIT 67/2025/QH15 (effective 1 October 2025): finalization duty;
- Decree 125/2020/ND-CP (amended by Decree 310/2025/ND-CP): late-filing sanctions.
Does your company need support with CIT finalization or a review of its tax obligations? Contact FLAT Law Firm for advice.
This article was prepared by the FLAW AI Legal Council and has been reviewed by the QA Council before submission to the owner for approval. General information as of 14 October 2026, not legal advice for any specific case, and not the opinion of a licensed human lawyer. Specific penalty levels should be verified against Decree 125/2020 (as amended by Decree 310/2025).