3 Important Tax Filing Deadlines in Early 2026 That Taxpayers Should be Aware of

Date: 2026.01.20

At the beginning of each calendar year (2026), taxpayers enter a “peak tax compliance period,” during which a large number of filings related to the final tax period of the previous year (2025) and annual tax finalization must be completed within a short timeframe. Even a delay of just a few days may result in monetary penalties ranging from several million to tens of millions of VND, not to mention daily late payment interest that continues to accrue.

During this period, taxpayers, businesses, and household businesses should pay special attention to the three key tax declaration and payment deadlines outlined below in order to avoid unnecessary legal risks and penalties.

1 ) Deadline 1: January 20, 2026 – Final Deadline for Monthly Tax Filing (December 2025)

📌 Applicable to the December 2025 tax period

Taxpayers are required to complete and submit monthly tax declarations no later than January 20, 2026, covering the following taxes:

– Value Added Tax (VAT)
– Personal Income Tax (PIT)
– Natural Resources Tax
– Other taxes and fees arising in accordance with regulations

👉 This is one of the most commonly missed deadlines, as it falls immediately after the New Year holiday, when many businesses are still in the process of reviewing and finalizing year-end financial data.

2) Deadline 2: February 2, 2026 – Final Deadline for Quarterly Tax Filing (Q4 2025)

📌 Applicable to the Q4 2025 tax period

The final deadline for submitting quarterly tax returns for Q4 2025 is February 2, 2026, including:

– Value Added Tax (VAT) return
– Personal Income Tax (PIT) return

⚠️ Important note: This deadline often falls very close to the Lunar New Year (Tết) holiday, so early preparation of tax documents is critical to avoid late filing and potential penalties.

3) Deadline 3: March 31, 2026 – Final Deadline for 2025 Annual Tax Finalization

📌 The most critical deadline in Q1/2026

No later than March 31, 2026, taxpayers must complete the 2025 annual tax finalization, including:

– Corporate Income Tax (CIT) finalization return for the 2025 calendar fiscal year
– Personal Income Tax (PIT) finalization return for 2025
– Financial statements for the 2025 calendar fiscal year

👉 This stage consolidates all key tax obligations in the early part of the year and is the period where errors most commonly occur, especially if accounting records have not been thoroughly reviewed and reconciled in advance.

4) Late Submission of Tax Returns and Late Tax Payment: Penalties Under Current Regulations

Under current regulations, both late submission of tax returns and late payment of taxes are subject to penalties, as follows:

🔹 Penalties for Late Submission of Tax Returns

Late by 1–30 days:
→ Warning or a fine ranging from VND 2–5 million

Late by 31–90 days:
→ Fine ranging from VND 5–15 million

Late by more than 90 days:
→ Fine ranging from VND 15–25 million

🔹 Late Payment Interest on Taxes

Late payment interest is charged at 0.03% per day on the outstanding tax amount.

⛔ These penalties are applied independently, meaning taxpayers may be subject to both administrative fines and late payment interest simultaneously if violations occur at the same time.

5) Invoice-Related Penalties Effective from January 16, 2026

Stricter Enforcement of Invoice Issuance Violations

In addition to tax filing deadlines, the tax authorities have issued an important warning regarding invoice compliance:

📢 Decree No. 310/2025/ND-CP (amending Decree No. 125/2020/ND-CP) has increased the penalty framework for invoice-related violations, and will take effect from January 16, 2026.

Violations such as:

– Issuing invoices at an incorrect time
– Failing to issue invoices when selling goods or providing services

👉 Will be penalized based on the number of violating invoices, which can result in significantly higher total fines compared to previous regulations.

The tax authorities emphasize that from January 16, 2026 onward, invoice errors will no longer be considered minor violations, and businesses must promptly review and strengthen their internal invoicing and compliance procedures.

According to representatives of the tax authorities, penalty regulations are not intended to generate fine revenue, but rather to ensure a fair and transparent business environment for all taxpayers.

Therefore, individuals, household businesses, and enterprises should:

– Proactively keep in mind the three key tax filing deadlines at the beginning of the year
– Review and reconcile accounting records and tax documents early
– Closely monitor and strictly control tax declarations and invoice issuance
– Correct errors promptly as soon as any discrepancies are identified

6) Proactive Compliance to Avoid Legal Risks

According to representatives of the tax authorities, penalty regulations are not intended to generate fine revenue, but rather to ensure a fair and transparent business environment for all taxpayers.

Therefore, individuals, household businesses, and enterprises should:

– Proactively keep in mind the three key tax filing deadlines at the beginning of the year
– Review and reconcile accounting records and tax documents early
– Closely monitor and strictly control tax declarations and invoice issuance
– Correct errors promptly as soon as any discrepancies are identified

7) Conclusion

Remembering and strictly complying with the three key tax filing deadlines at the beginning of the year not only helps taxpayers avoid administrative penalties and late payment interest, but also minimizes the risk of inspections and enforcement actions during tax administration.

In the context where tax and invoice regulations are increasingly tightened and strictly enforced, especially with regard to late submissions or filing errors, proactive preparation, early review, and timely compliance remain the most effective solutions for businesses to control costs, ensure legal compliance, and maintain stable, long-term operations.