Guidance on procedures and tax finalization obligations upon a change of the annual accounting period

On 25 August 2026, the Khanh Hoa Provincial Tax Authority issued Official Letter No. 4592/KHH-QLDN1 responding to a request for guidance on the procedures for changing the annual accounting period. The Official Letter clarifies two matters an enterprise must address: notifying the competent authorities before the conversion and finalizing taxes for the transitional period.

1. Enterprises may adopt an annual accounting period other than the calendar year

Under Clause 1, Article 12 of the Law on Accounting No. 88/2015/QH13, the annual accounting period is 12 months, running from 1 January to 31 December of the calendar year. An accounting entity with particular organizational or operational characteristics may adopt an annual accounting period of 12 full months, beginning on the first day of the first month of a quarter and ending on the last day of the final month of the preceding quarter of the following year, and must notify the finance authority and the tax authority accordingly.

Correspondingly for tax purposes, Clause 1, Article 5 of the Law on Corporate Income Tax No. 67/2025/QH15 provides that the corporate income tax (CIT) period is determined according to either the calendar year or a fiscal year chosen by the enterprise.

2. Notification procedures for a change of the accounting period

The Khanh Hoa Provincial Tax Authority instructs enterprises to take the following two actions concurrently:

First, notify the change of tax registration information together with the amendment of enterprise registration or business registration particulars at the business registration authority, in accordance with the tax registration provisions of Clauses 1 and 2, Article 10 of the Law on Tax Administration No. 108/2025/QH15 (tax registration is carried out together with enterprise registration under the interlinked single-window mechanism).

Second, notify the directly managing tax authority (the Khanh Hoa Provincial Tax Authority) before implementing the conversion of the CIT period, in accordance with Clause 1, Article 5 of the Law on Corporate Income Tax No. 67/2025/QH15.

3. The tax period of the transitional year must not exceed 12 months - enterprises enjoying tax incentives may elect the year in which incentives apply

Under Point b, Clause 6, Article 23 of Decree No. 320/2025/ND-CP dated 15 December 2025, where an enterprise converts its CIT period (whether from the calendar year to a fiscal year or vice versa), the tax period of the transitional year must not exceed 12 months. An enterprise that is within a CIT incentive period at the time of conversion may elect one of two options: to apply the incentives in the transitional year itself, or to pay tax at the non-incentive rate for the transitional year and carry the incentives forward to the following year.

4. Tax finalization for the transitional period

Under Clauses 1 and 2, Article 9 of Decree No. 252/2026/ND-CP dated 30 June 2026, the tax finalization period is determined according to the annual accounting period under accounting law, except that the personal income tax (PIT) finalization period is always determined on a calendar-year basis.

In the specific case addressed by the Official Letter, the transitional period runs from 1 January 2027 to 31 March 2027. Pursuant to Clause 5, Article 10 of Decree No. 252/2026/ND-CP, the deadline for filing the tax finalization dossier is no later than the last day of the third month following the end of the tax finalization period - i.e., 30 June 2027 (except for the PIT finalization dossier, as the PIT finalization period remains on a calendar-year basis).

On the accounting side, the Official Letter refers to Article 21 of Circular No. 99/2025/TT-BTC dated 27 October 2025 of the Ministry of Finance on the principles for preparing and presenting financial statements upon a change of the accounting period. Accordingly, when changing its accounting period, an enterprise must close its accounting books and prepare separate financial statements for the transitional period.

💡 Recommendations for enterprises

1. Review whether the enterprise satisfies the "particular organizational or operational characteristics" condition and select an annual accounting period beginning on the first day of a quarter, in accordance with Clause 1, Article 12 of the Law on Accounting No. 88/2015/QH13.
2. File the notification of change of tax registration information together with the dossier for amendment of enterprise registration at the business registration authority, and at the same time submit the notification to the directly managing tax authority before the new tax period takes effect.
3. To avoid system errors on the electronic tax filing platform (iHTKK) when submitting returns for the new period, enterprises should complete these filings 15 to 30 days before the new tax period begins.
4. Enterprises currently enjoying CIT incentives should assess and decide on the incentive option for the transitional year under Point b, Clause 6, Article 23 of Decree No. 320/2025/ND-CP before filing the finalization return.
5. Establish a separate finalization timetable for the transitional period, noting that PIT finalization remains on a calendar-year basis (Clause 2, Article 9 of Decree No. 252/2026/ND-CP).

>>> Download Official Dispatch 4592/KHH-QLDN1

This newsletter is prepared by Crowe Vietnam for general information purposes only and does not constitute advice for any specific case. Enterprises should refer to the original legal instruments and consult professional advisors before applying the above to their particular circumstances.