The clock is ticking for companies in Thailand as the statutory Corporate Income Tax filing deadline rapidly approaches on May 30—a critical date that all business owners must mark on their calendars. For most companies in Thailand, this deadline falls 150 days after the fiscal year-end, which is typically December 31. Whether you’re a newly registered company, a startup with minimal transactions, or a growing SME—compliance is non-negotiable.
What Needs to Be Filed by May 30?
This important deadline covers two mandatory filings:
- Por Nor Dor 50 (PND.50) – The Thai Corporate Income Tax Return to be filed with the Thai Revenue Department.
- Sor Bor Chor 3 (SBC.3) – Filing of audited financial statements with the Department of Business Development (DBD) under the Ministry of Commerce.
Failure to comply with either of these requirements can result in serious legal consequences, including financial penalties and criminal liability for directors—even imprisonment under Thai law.
Every Company Must File—No Exceptions!
Even if your company had no transactions, or was incorporated late in 2024, the law still requires you to file both your tax return and your audited financial statements. Thai authorities do not grant exemptions based on size, inactivity, or novelty.
Don’t risk penalties or a criminal record—make sure your company complies in full with all statutory requirements. AO Accounting & Advisory is here to help you do just that—accurately, on time, and with peace of mind.
Why You Need a Proper Accountant of Record
Filing Por Nor Dor 50 (PND.50) and Sor Bor Chor 3 (SBC.3) is not a mere administrative task—it requires the expertise of a licensed, experienced accountant of record who understands Thailand’s complex tax code and corporate compliance regulations.
The process involves:
• Preparing and reconciling your financial statements according to Thai Financial Reporting Standards (TFRS)
• Computing your company’s net profit, taxable income, and withholding taxes
• Ensuring the correct format and content for submission to both the Revenue Department and the DBD
• Having your accounts audited by a licensed Thai CPA
A reliable accountant doesn’t just help you file forms—they ensure full compliance, reduce your audit risk, and protect your company and its directors from fines and liability.
How to Request a Withholding Tax Refund (and Survive a Thai Tax Audit)
If your business has overpaid withholding tax during the year, you may be entitled to a tax refund—but beware: this triggers an automatic tax audit by officers from the Thai Revenue Department. Don’t panic—just be prepared.
Here’s how AO Accounting & Advisory helps you through the process:
- Review and reconcile all withheld tax documents (PND.1, PND.3, PND.53)
- Prepare accurate tax schedules supporting the overpaid amount
- Represent your company during any audit queries or visits from Revenue Department officers
- Minimize the risk of assessment adjustments or rejection of the refund claim
Tax audits in Thailand are detailed and document-heavy. Having a professional team that knows what auditors are looking for gives you the best chance of success—and your money back.
Don’t Navigate This Alone—AO is Here for You
At AO Accounting & Advisory, we have more than 18 years of experience helping companies of all sizes comply with Thai tax laws, prepare financial statements, and manage the full audit process. Our services include:
✔️ Tax Compliance & Filing (PND.50, VAT, withholding tax)
✔️ Audited Financial Statements preparation & coordination with licensed CPAs
✔️ Withholding Tax Refund Applications
✔️ Representation during Revenue Department Audits
✔️ Full bookkeeping and accounting services for Thai and foreign-owned businesses
Whether you’re an established company or just getting started in Thailand, we handle the tax and accounting—so you can focus on growing your business.
FAQs About Tax Filing Deadline Day 2025
Q: What is the tax deadline for filing tax returns in Thailand for the year 2025?
A: The tax deadline for filing your tax return in Thailand for the year 2025 is May 30, 2025. This is the last day to file your return for the fiscal year.
Q: How can I file my tax return in Thailand?
A: You can file your tax return in Thailand electronically through the Revenue Department’s e-filing system, or you can file your tax return by submitting a paper form at your local tax office.
Q: What happens if I miss the deadline to file my taxes in Thailand?
A: If you miss the deadline to file your taxes in Thailand, you may incur late filing penalties and interest on the tax owed. It is crucial to file your tax return on time to avoid these additional charges.
Q: Can I request a tax extension in Thailand?
A: Yes, you can file for an extension to file your taxes in Thailand. You must submit a request for an extension before the tax deadline. This allows you additional time to file your tax return, but you are still required to pay any taxes owed by the original deadline.
Q: What is considered the tax season in Thailand?
A: The tax season in Thailand typically runs from January 1 to May 30 each year, during which taxpayers are required to prepare and file their income tax returns for the previous calendar year.
Q: What are the tax rules regarding foreign income for taxpayers in Thailand?
A: Taxpayers in Thailand are required to report their worldwide income, including foreign income, on their income tax return. However, tax treaties may provide relief from double taxation on certain types of foreign income.
Q: What documents do I need to file my tax return in Thailand?
A: To file your tax return in Thailand, you typically need your income statements, withholding tax certificates, and any relevant deductions or credits you wish to claim. It’s advisable to consult a tax professional for specific requirements.
Q: Is it possible to file my taxes electronically in Thailand?
A: Yes, taxpayers in Thailand can file their taxes electronically using the Revenue Department’s e-filing system, which is a convenient way to submit your tax return and receive acknowledgments.
Q: What should I do if I am unsure about how to file my income tax return in Thailand?
A: If you are unsure about how to file your income tax return in Thailand, it is recommended to consult a tax professional who can guide you through the process and ensure compliance with tax regulations.