Official Document 1376/TCS10-QLDN The tax regulations issued by Vinh Long Provincial Tax Department on March 31, 2026, are attracting significant attention from accountants and the business community. The most important aspect of this document is the complete termination of the mechanism of combining corporate income tax periods of less than three months into the next tax period.
Previously, according to Circular 78/2014/TT-BTCPreviously, newly established businesses or businesses with a last tax period of less than 3 months were allowed to accumulate their tax liability in the following or preceding year for final settlement. However, this regulation will no longer apply starting from the 2025 tax year. This means that all businesses, even those operating for a very short time, must still prepare separate tax settlement documents for the period in which the tax liability arose.
New regulations on corporate income tax calculation period from 2025.
The changes outlined in Official Letter 1376/TCS10-QLDN stem from the new legal framework regarding corporate income tax. The goal is to tighten management, limit the accumulation of data between fiscal years, and enhance transparency in tax declarations.
According to current regulations, the corporate income tax period is determined by the calendar year. If a business uses a fiscal year different from the calendar year, the tax period will be determined by the registered fiscal year.
Notably, from 2025 onwards, there will be no exceptions for short tax periods of less than three months. Businesses must declare and settle taxes separately for each period, even if their operating time only lasts a few days.
Legal basis related to Official Letter 1376/TCS10-QLDN
Businesses need to monitor multiple documents simultaneously to properly implement the instructions in Official Letter 1376/TCS10-QLDN, including:
- The Corporate Income Tax Law No. 67/2025/QH15 will take effect from October 1, 2025.
- Decree 320/2025/ND-CP provides guidance on the implementation of the Corporate Income Tax Law.
- Circular 20/2026/TT-BTC was issued on March 12, 2026.
- Official document No. 1376/TCS10-QLDN dated March 31, 2026, from the Vinh Long Provincial Tax Department.
Specifically, Circular 20/2026/TT-BTC directly repeals Clause 3, Article 3 of Circular 78/2014/TT-BTC, which previously allowed the merging of the first or last tax period of less than 3 months.
What changes does Official Document 1376/TCS10-QLDN bring compared to previous documents?
Prior to 2025, newly established businesses at the end of the year were generally not required to prepare separate financial statements if they had been operating for less than three months. Instead, the data was carried over to the following year for general settlement.
However, according to Official Letter 1376/TCS10-QLDN, this method of handling has been officially abolished. From now on:
- Tax periods of less than 3 months cannot be carried over to the following year.
- The final tax period of a dissolved, merged, or transformed business cannot be combined with the preceding period.
- Each tax period in which tax obligations arise must have separate financial statements and settlement documents.
This requires accountants to accurately track when a business starts operating, ceases operations, or changes its type in order to determine the correct tax period.
What should businesses established at the end of 2025 be aware of?
According to the guidelines in Official Letter 1376/TCS10-QLDN, businesses granted business registration certificates between October 1, 2025 and December 31, 2025 must still prepare separate financial statements and corporate income tax returns for 2025.
For example, a business established on November 15, 2025, and operating for only 46 days, must still:
- Prepare financial statements for the period from November 15, 2025 to December 31, 2025.
- Corporate income tax return form 03/TNDN.
- Applications must be submitted no later than the last day of the third month following the end of the fiscal year.
Therefore, businesses can no longer request to transfer all of this data to 2026 as before.
In the case of business dissolution, merger, or transformation.
Not only newly established businesses, but also cases involving changes in business structure must carry out separate final tax settlements for the last period.
| In case of occurrence | The end of the tax period | Deadline for submitting settlement documents. |
| Dissolution or bankruptcy | Date of dissolution or bankruptcy decision | Within 45 days. |
| Mergers and acquisitions | The old business ceased to exist. | Within 45 days |
| Change of business type | Date the new business registration certificate was issued | Within 45 days |
| Business division and separation | Date the former legal entity ceased operations | Within 45 days |
Note: If businesses submit their tax return documents late according to the above deadlines, the tax authorities may impose administrative penalties in accordance with Decree 125/2020/ND-CP.
Instructions for declaration according to Official Letter 1376/TCS10-QLDN
To avoid errors when applying the new regulations, the accounting department should follow these steps:
Step 1: Determine the exact operating hours.
It is necessary to check the date recorded on the business registration certificate, dissolution decision, or conversion documents to accurately determine the tax period in which it arises.
Step 2: Prepare separate financial statements for the short-term period.
Even if a business has been operating for less than 3 months, it must still prepare complete financial reports according to the new form specified in Circular 20/2026/TT-BTC.
Step 3: File a separate corporate income tax return.
Revenue, expenses, and profits/losses for short-term periods must be accounted for and declared separately on the tax return form 03/TNDN. Data cannot be carried over to the next period.
Step 4: Submit the electronic application and save the documents.
After completing the declaration, businesses need to submit the documents on the electronic tax system and retain the submission receipt for future verification or tax audits.
Conclude
Official document 1376/TCS10-QLDN marks a major change in the way corporate income tax periods are determined from 2025. The discontinuation of combining tax periods under 3 months will directly affect newly established businesses, businesses that are dissolved, merged, or changing their business type.
Therefore, accountants and business owners need to review the entire financial reporting process, correctly identify the tax period, and prepare settlement documents in a timely manner to avoid the risk of penalties.
Businesses needing assistance in processing documents according to the new regulations should refer to the following information. accounting services This will help save time, minimize errors, and ensure full compliance with the requirements of Official Letter 1376/TCS10-QLDN.
Contact information MAN – Master Accountant Network
- Address: No. 19A, Street 43, Tan Thuan Ward, Ho Chi Minh City
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Content production by: Mr. Le Hoang Tuyen – Founder & CEO MAN – Master Accountant Network, Vietnamese CPA Auditor with over 30 years of experience in Accounting, Auditing and Financial Consulting.
Clarification of new regulations in Official Letter 1376/TCS10-QLDN
Yes. According to Official Letter 1376/TCS10-QLDN, businesses established in December 2025 must still prepare separate financial statements and corporate income tax settlement documents for the period from the date of issuance of the business registration certificate to December 31, 2025, even if they only operate for a few days.
No. The new regulations have completely abolished the mechanism of consolidating tax periods of less than 3 months into the following year. Even if a business has not yet generated revenue, issued invoices, or has only incurred initial expenses, it must still file a separate tax return for the 2025 tax year.
Yes. Businesses that fail to submit or submit their tax return late will be penalized according to Decree 125/2020/ND-CP. The penalty depends on the number of days of delay, and the business may also be required to submit additional documents and provide explanations to the tax authorities.
Yes. Circular 1376/TCS10-QLDN still applies to businesses using a fiscal year different from the calendar year. In this case, the tax period is determined according to the registered fiscal year, but if the first or last period is less than 3 months, the business must still prepare a separate tax return; it cannot be combined as before.
No. According to Official Letter 1376/TCS10-QLDN, businesses that dissolve, go bankrupt, split, merge, or change their legal form must prepare separate final settlement documents for the last period. These documents must be submitted within 45 days from the date of the decision or legal event. Is it mandatory for a business established in December 2025 to file a separate corporate income tax return?
Can tax periods of less than 3 months be carried over to 2026 if no revenue has been generated?
If a business forgets to submit its tax return for a short period of less than 3 months, will it be penalized?
Do businesses that use a fiscal year different from the calendar year have to comply with Circular 1376/TCS10-QLDN?
Can a business undergoing dissolution procedures in 2025 combine its final tax period with the previous year's tax period?
