Short answer: The annual CIT finalization return must be filed no later than the last day of the 3rd month following the end of the calendar or fiscal year (Article 10 of Decree 252/2026/ND-CP) — for a fiscal year aligned with the calendar year, the deadline is 31 March. This is the new deadline, replacing 30 April under the old rules (the old deadline ceased to apply from 01/7/2026). Any remaining CIT payable after finalization must be paid no later than the same filing deadline. Two separate extension mechanisms exist: filing extensions (force majeure only, up to 60 days for finalization — clause 4, Article 13 of Law 108/2025) and tax payment extensions (clause 7, Article 14 of Law 108/2025; the specific 2026 policy in Decree 245/2026).
1. Legal framework in force as of 14/10/2026
- Law on Tax Administration 2025 No. 108/2025/QH15 (10/12/2025) — effective 01/7/2026, replacing Law 38/2019/QH14. Article 13 (filing/withholding/filing extensions), clause 7 Article 14 (tax payment extensions), clause 2 Article 16 (late payment at 0.03%/day);
- Decree 252/2026/ND-CP (30/6/2026) guiding the Law — Article 10 (tax filing deadlines), Article 25 (tax payment extensions);
- Decree 245/2026/ND-CP (27/6/2026) on 2026 tax payment extensions — effective 27/6/2026 to 30/12/2026.
Validity note: Article 44 of Law 38/2019/QH14, Decrees 126/2020/ND-CP and 91/2022/ND-CP, and Circular 80/2021/TT-BTC are no longer in force — do not cite.
2. Filing deadline: end of the 3rd month, no longer the 4th
- Annual finalization return: no later than the last day of the 3rd month after the calendar or fiscal year-end (Article 10 of Decree 252/2026). Calendar fiscal year → 31 March;
- Transition marker: the old rule (4th-month deadline, i.e. 30 April) ceased to apply from 01/7/2026. The 2025 finalization was already filed under the old law (4th-month deadline) — this article states the transition clearly so readers don’t misapply it to the 2025 period;
- Cessation of operations (dissolution, bankruptcy, division, split, merger): no later than the 45th day from the triggering event.
3. Tax payment deadline matches the filing deadline
As a general principle, remaining CIT payable after finalization must be paid no later than the last day of the finalization filing period. Underpayment vs. the finalized amount → late-payment interest at 0.03%/day (clause 2, Article 16 of Law 108/2025).
4. FILING extensions — force majeure only
A general mechanism allows extending tax filing deadlines in force-majeure cases (defined in clause 21, Article 4 of Law 108/2025):
- Monthly/quarterly/annual/per-occurrence filings → extension of no more than 30 days;
- Finalization filings → extension of no more than 60 days from the filing deadline (clause 4, Article 13 of Law 108/2025 — verified against the original text).
Citation note: clause 4, Article 13 of Law 108/2025 covers filing extensions; the withholding/declaration/payment-on-behalf principle sits in clause 3, Article 13 — don’t mix the two clauses.
5. TAX PAYMENT extensions — a separate mechanism
Under clause 7, Article 14 of Law 108/2025, tax payment extensions apply where: (a) material damage from force majeure directly affects production/business; (b) operations must cease due to relocation of production/business premises at a competent state authority’s request; (c) special cases prescribed by the Government. During the extension period, no late-payment interest accrues on the extended tax amount.
6. Special 2026 extension (Decree 245/2026): extends PAYMENT only, not filing
The distinction to draw sharply:
- Decree 245/2026 extends only the TAX PAYMENT deadline — late filing is still penalized even where the tax payment was extended;
- Scope: quarterly provisional CIT — Q2/2026 extended by 3 months (no later than 02/11/2026); Q3/2026 extended by 2 months (no later than 30/12/2026). Not the annual finalization amount — no broader reading;
- Eligible taxpayers: enterprises in the sectors listed in the Decree’s Appendix I and small/micro enterprises;
- Procedure: a written extension request is required (no later than 02/11/2026 if not filed with the tax return); no late-payment interest during the extension.
7. Supplementary returns — the fix for filed errors
After filing the finalization return, errors discovered later may be corrected via supplementary filing (Law 108/2025 and Decree 252/2026). This remedies mistakes — it does not replace the duty to file correctly and on time.
8. Risks and practical recommendations
- Memorize the new 31 March date: accounting teams used to the old 30 April deadline can easily miss the 2026 finalization — update internal compliance calendars now;
- Distinguish the two extensions: filing extensions (force majeure, finalization ≤ 60 days) differ from payment extensions (Decree 245/2026 and year-specific policies) — wrong type means wrong conditions;
- Decree 245/2026 does not “save” late filings: extended provisional quarterly payments don’t extend filing deadlines;
- Late-filing penalties sit in the tax administrative-sanctions decree — the current text is unverified → this article gives no figures; check the original text before applying.
FAQs
What is the 2026 CIT finalization filing deadline?
31/3/2027 (last day of the 3rd month after FY2026 year-end) — Article 10 of Decree 252/2026.
When must the finalized tax be paid?
No later than the last day of the finalization filing period; underpayment accrues 0.03%/day (clause 2, Article 16 of Law 108/2025).
How long can a finalization filing be extended?
No more than 60 days from the deadline, force majeure only (clause 4, Article 13 of Law 108/2025).
Does Decree 245/2026 extend finalization filing?
No — it extends only the payment deadline for Q2 and Q3/2026 provisional CIT, not filing.
Legal sources
- Law on Tax Administration 2025 No. 108/2025/QH15 (10/12/2025, effective 01/7/2026).
- Decree 252/2026/ND-CP (30/6/2026) — Articles 10 and 25.
- Decree 245/2026/ND-CP (27/6/2026) — 2026 tax payment extensions (effective to 30/12/2026).
Need to review your annual CIT finalization calendar, tax filings or eligibility for a tax payment extension? Reach us via the Contact page of FLAT Law Firm.
The legal content of this article is reviewed by FLAT’s AI Legal Council and submitted to the owner for approval; it is not an opinion of a licensed lawyer and does not replace legal advice for specific cases.
For reference only, not legal advice.
