CIT finalisation Q&A: the 10 questions business owners ask most

The 2026 CIT finalisation is the first to apply together the Law on Corporate Income Tax No. 67/2025/QH15, the Law on Tax Administration No. 108/2025/QH15 and their new implementing decrees. Below are the 10 questions we hear most often from business owners and CFOs, answered briefly with the legal basis.

Deadlines and provisional payments

1. When is the CIT finalisation return due?

No later than the last day of the third month after the end of the financial year (Article 10, Decree 252/2026/ND-CP). For a 2026 calendar financial year, the deadline is 31 March 2027. Any tax still payable under the finalisation must be paid by the same deadline. The dossier includes the finalisation return, the annual financial statements and relevant appendices such as tax incentives, loss carry-forward and related-party transactions.

2. How much provisional tax is enough each quarter?

Companies determine their own quarterly provisional payments, due by the last day of the first month of the following quarter. Under Article 24 of Decree 252/2026/ND-CP, total provisional payments for the four quarters must be at least 80% of the tax payable per the finalisation; otherwise late-payment interest applies to the shortfall, starting from the day after the fourth-quarter provisional deadline. Illustrative example: if 2026 CIT per finalisation is VND 500 million, provisional payments for the four quarters must total at least VND 400 million; if only VND 300 million was paid, the VND 100 million shortfall attracts late-payment interest of 0.03% per day from 1 February 2027.

Tax rates and losses

3. Can small businesses pay less than 20%?

Yes. The Law on Corporate Income Tax No. 67/2025/QH15 (effective 1 October 2025, applying from the 2025 tax year) sets a 15% rate for enterprises with total annual revenue of up to VND 3 billion and 17% for those with total revenue above VND 3 billion and up to VND 50 billion; the standard rate remains 20%. According to Ministry of Finance guidance, the revenue used to determine the rate is that of the immediately preceding tax year. Detailed conditions are set out in Decree 320/2025/ND-CP.

4. How long can losses be carried forward?

Losses may be carried forward for up to 5 consecutive years, starting from the year after the loss arose. The company determines the loss itself and offsets it against taxable income at finalisation; after 5 years, any unused loss expires. If a declared loss is later adjusted by a tax inspection, the adjusted figure must be carried forward.

Deductible expenses

5. Is an invoice of VND 5 million paid in cash deductible?

No. Decree 320/2025/ND-CP lowered the mandatory non-cash payment threshold from VND 20 million to VND 5 million (VAT inclusive) to align with the VAT deduction rules. The new threshold applies from the decree's effective date (15 December 2025) and is not retroactive for the whole 2025 tax year. For 2026, every expense of VND 5 million or more needs non-cash payment evidence to be deductible.

6. Are salaries and bonuses paid after 31 December deductible?

Yes, if actually paid before the finalisation filing deadline and supported by the labour contract, collective labour agreement or pay and bonus policy. Amounts still unpaid by the finalisation deadline are not deductible for that year. Note that Decree 320/2025/ND-CP expressly disallows expenses that breach sector-specific laws, such as overtime pay exceeding the limits under labour law.

7. What is the cap on employee welfare spending?

Total direct welfare spending is capped at one month of actual average salary, i.e. the actual salary fund for the year divided by 12 (Clause 4, Article 10, Decree 320/2025/ND-CP). Items typically in this group:

• Holidays and trips for employees.
• Wedding and funeral support for employees and their families.
• Support for medical treatment and check-ups.
• Education support and awards for employees' children with good results.

Contributions to voluntary pension or life insurance for employees have a separate cap of VND 5 million per person per month, and the conditions and benefit levels must be stated in the labour contract or collective agreement.

Errors, profit remittance and related-party transactions

8. What if we find an error after filing the finalisation?

File a supplementary return as soon as possible. The 2025 Law on Tax Administration shortens the window for supplementary returns to 5 years from the filing deadline of the period in error. If the correction increases tax payable, late-payment interest is due. After 5 years, under Decree 252/2026/ND-CP, adjustments are only considered through an explanation dossier in cases that increase tax payable or reduce deductible or refunded tax.

9. When can an FDI company remit profits to its parent?

Under Decree 252/2026/ND-CP, foreign investors may remit profits abroad only after the Vietnamese company has filed its audited financial statements and CIT finalisation return, settled taxes, late-payment interest and penalties that have fallen due, and has no outstanding tax debt at the time of remittance. When terminating the investment, obligations not yet due must also be settled.

10. What should companies with related-party transactions watch at finalisation?

From the 2026 tax year, Decree 255/2026/ND-CP replaces Decree 132/2020/ND-CP and Decree 20/2025/ND-CP, changing the priority order of comparable databases and widening the exemption thresholds for transfer pricing documentation. Companies must still declare related-party information with the finalisation dossier, and expenses inconsistent with the arm's length principle will be disallowed. On the interest deduction cap (30% of EBITDA under Decree 132/2020/ND-CP up to the 2025 tax year), check the corresponding provisions of Decree 255/2026/ND-CP before closing your 2026 figures.

How Kaizen can help

Kaizen performs pre-finalisation reviews, estimates fourth-quarter provisional payments, checks expenses at risk of disallowance and prepares related-party documentation for SMEs and FDI companies. Book a free tax health check to enter the 2026 finalisation season with as few surprises as possible.