The accounting work schedule for September 2026 can be summarized into three main groups of tasks:
- Submit a notification of labor force changes.
- Complete the four monthly tax returns for the period of August 2026;
- And pay union dues and mandatory social insurance contributions.
Missing even one deadline can lead to late payment penalties, administrative fines, or interest charges. This article outlines the complete accounting work schedule for September 2026, along with specific legal basis, to help accountants and HR personnel proactively plan before the deadline approaches.
Why is the September 2026 accounting work schedule a milestone that businesses cannot afford to miss?
September brings a greater workload than usual, with the need to file monthly tax returns for the period ending in August 2026, as well as deadlines for monthly payments such as union dues and mandatory social insurance contributions. Having a firm grasp of the accounting work schedule for September 2026 helps businesses avoid three common risks:
- Late filing of tax returns results in administrative penalties according to tax management regulations.
- Late payment of social insurance contributions results in interest charges on union fees and affects the rights of workers.
- Failing to notify local labor authorities of changes in workforce numbers prevents businesses from fulfilling their obligations.
The following section details each task in the September 2026 accounting work schedule, arranged in order from most recent to most recent.
Detailed accounting work schedule for September 2026, broken down by task.
Notification of labor turnover for August 2026: Deadline September 3rd
If a business experiences labor changes (new hires, contract terminations, position changes, etc.) in August 2026, the employer must submit a Notice of Labor Changes using Form No. 29 issued with Circular 28/2015/TT-BLDTBXH to the Employment Service Center where the business is located before the 3rd of each month. The notification should be based on the calendar month immediately preceding the notification date, meaning the data reported in the accounting work schedule for September 2026 should reflect labor changes that occurred in August 2026.
Legal basis: Clause 2, Article 16 of Circular 28/2015/TT-BLDTBXH.
Four types of tax returns for August 2026 must be submitted before September 21st.
This is the largest group of tasks in the September 2026 accounting work schedule, because the general principle with monthly tax filing is that the deadline for submitting tax returns is no later than the 20th day of the month following the month in which the tax liability arises. Four types of tax returns need to be completed:
- VAT tax return for August 2026 (Applicable to businesses not eligible for tax payment extension under Decree 245/2026/ND-CP) no later than 21/9.
- Excise tax return form for August 2026Special Consumption Tax is a tax declared monthly, except in some cases where it is declared on a case-by-case basis, no later than the deadline. 21/9.
- Resource tax return form for August 2026Resource tax is declared monthly and settled annually, no later than the deadline. 21/9.
- Environmental Protection Tax Declaration Form August 2026Environmental protection tax must be declared monthly, no later than... 21/9.
These four tax returns all fall within the same timeframe in the September 2026 accounting work schedule, so businesses with multiple types of taxes to pay need to prepare the data simultaneously to avoid a backlog of work in the final days.
Trade union fees and mandatory social insurance contributions for August 2026: Deadline September 30th.
Concluding the accounting work schedule for September 2026 are two monthly payments with the same deadline:
- Trade union funds for August 2026: For agencies, organizations, units, enterprises, cooperatives, and cooperative unions that pay trade union fees monthly, the deadline for payment is no later than the last day of the following month. 30/9.
- Mandatory social insurance contributions as of August 2026: With the monthly payment method, the employer must deduct and remit the payment no later than the last day of the following month, i.e. 30/9.
Summary of accounting work schedule for September 2026
Below is a detailed and complete work schedule for September 2026 that accounting and HR departments need to know:
Summary of accounting work schedule for September 2026.
| No. | Job | Submission deadline | Legal basis |
| 1 | Notification of labor force changes in August 2026 (if any) | Before September 3rd | Clause 2, Article 16 of Circular 28/2015/TT-BLDTBXH |
| 2 | VAT tax return for August 2026 | No later than September 21st | Clause 2, Article 10 of Decree 252/2026/ND-CP; Decree 245/2026/ND-CP |
| 3 | Excise tax return form for August 2026 | No later than September 21st | Clause 1, Article 20 of Circular 89/2026/TT-BTC; Clause 2, Article 10 of Decree 252/2026/ND-CP |
| 4 | Resource tax return form for August 2026 | No later than September 21st | Article 8 of the 2009 Law on Resource Tax; Clause 1, Article 23 of Circular 89/2026/TT-BTC; Clause 2, Article 10 of Decree 252/2026/NĐ-CP |
| 5 | Environmental Protection Tax Declaration Form August 2026 | No later than September 21st | Article 10 of the 2010 Environmental Protection Tax Law; Clause 1, Article 24 of Circular 89/2026/TT-BTC; Clause 2, Article 10 of Decree 252/2026/ND-CP |
| 6 | Trade union funds for August 2026 | 30/9 | Clause 2, Article 4 of Decree 105/2026/ND-CP |
| 7 | Compulsory social insurance as of August 2026 | 30/9 | Clause 4, Article 34 of the Social Insurance Law 2024 |
Understanding each deadline and basis not only helps accountants feel confident when questioned during audits, but also provides a foundation for accurately identifying whether their business is eligible for extensions, exemptions, or exceptions.
Please note that the deadline in the September 2026 accounting work schedule may coincide with a holiday.
An important principle to remember when checking the accounting work schedule for September 2026: If the deadline for filing tax returns coincides with a statutory holiday, the deadline for filing tax returns will be the next working day after that holiday, as stipulated in the 2015 Civil Code and Article 86 of Circular 80/2021/TT-BTC.
This principle applies to the "20th day of the following month" deadline in particular, and all tax filing deadlines in general. Accountants should check the official holiday schedule for 2026 before finalizing the last filing date, instead of assuming the exact date stated in the document.
Solutions to help businesses avoid missing accounting tasks for September 2026.
For businesses with multiple tax obligations arising simultaneously, an effective way to avoid missing accounting deadlines in September 2026 is to standardize the process of tracking deadlines with separate reminders for each type of obligation, regularly comparing them with current legal documents instead of relying on past experience.
For businesses that lack sufficient dedicated accounting staff to track multiple deadlines simultaneously, please refer to the following: full accounting service This approach helps ensure that all tax returns, union dues, and mandatory social insurance contributions are tracked and submitted on time without having to build the process from scratch. For newly established or expanding businesses, this toutsource accounting services This also helps reduce the operating costs of the internal accounting department while still ensuring full compliance with the monthly accounting work schedule deadlines.
If a business is still facing difficulties with a specific task, for example, determining whether it is eligible for an extension of the VAT declaration deadline under Decree 245/2026/ND-CP, it should proactively take action. accounting consulting services Instead of relying on professional and experienced organizations like MAN – Master Accountant Network before the deadline, you should consult with them before making your own judgments and risking late submission.
Conclude
The accounting work schedule for September 2026 revolves around three groups of tasks:
- Notification of labor turnover (before September 3rd)
- Four monthly tax returns for the period of August 2026 (no later than September 21st).
- And union fees along with mandatory social insurance (September 30).
Each deadline is linked to a specific legal basis, and the principle of extending the deadline when it coincides with a holiday always needs to be checked before finalizing the submission date.
Businesses that proactively schedule their accounting work for September 2026 at the beginning of the month, instead of handling everything in the final days, will significantly reduce the risk of late payments and unnecessary penalties and interest charges.
For any questions or assistance, please contact your company. Contact MAN – Master Accountant Network:
Contact information MAN – Master Accountant Network
- Address: No. 19A, Street 43, Tan Thuan Ward, Ho Chi Minh City
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Responsible for production and professional content review by: Mr. Le Hoang Tuyen – Founder & CEO of MAN – Master Accountant NetworkHe is a CPA Vietnam auditor with over 30 years of in-depth experience in accounting, auditing, taxation, and corporate legal consulting.
