A Study and Practical Guide to Thailand’s Corporate Income Tax System

ZLYan Views: 15 2025-07-21 12:00:00 Comments: 0

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TMA Group is a professional company focusing on local recruitment and corporate consulting in Thailand, dedicated to providing one-stop services including recruitment, financial management, tax disposal, legal consulting, personnel management, etc. for enterprises and individuals. If you need more advice on investment in Thailand, please feel free to contact us.

I. Introduction

Corporate Income Tax (CIT) is a principal form of direct taxation in Thailand, levied on the income of enterprises and other legal entities within its tax jurisdiction. A correct understanding of its legal framework, scope of applicability, tax rate structure, and compliance obligations is fundamental to ensuring business continuity, tax compliance, and effective risk management. This paper systematically outlines the core components and practical filing procedures of the Thai CIT regime, based on the latest provisions of the Thai Revenue Code.

II. Legal Basis

The administration of corporate income tax in Thailand is primarily governed by Chapter 8, Sections 65 to 76 of the Revenue Code, and falls under the supervision of the Revenue Department of Thailand. Filing and payment services are facilitated via its electronic system, RD e-Filing.

III. Taxpayers

Entities subject to CIT include companies incorporated in Thailand and foreign companies with a Permanent Establishment (PE) in Thailand. These include, but are not limited to:

• Limited companies

• Branches of foreign companies

• Partnerships

• Trusts or funds

• Foreign entities conducting agency business in Thailand (e.g., permanent representatives)

Regardless of whether a company generates profits or is actively operating, it is required to file tax returns as long as its registration status is “Active.”

IV. Tax Rate Structure and Applicable Standards

According to announcements by the Revenue Department and interpretations of Section 65 of the Revenue Code, Thailand has adopted a unified standard corporate income tax rate of 20% since 2015, with progressive tax concessions granted to small and medium-sized enterprises (SMEs).

Type	Applicable Conditions	Tax Rate
General Enterprises	Entities that do not meet the criteria for SMEs in terms of registered capital and revenue	20%
SME Enterprises	Registered capital not exceeding THB 5 million and annual revenue not exceeding THB 30 million	0% for income ≤ THB 300,000; 15% for income between THB 300,001 and THB 3,000,000; 20% for the portion exceeding THB 3,000,000
BOI-Promoted Enterprises	Tax exemption granted based on the scope and period approved by the Board of Investment (BOI)	0% for a period of 3 to 8 years
Specific Industries	Including sectors such as shipping, oil and gas, and Regional Operating Headquarters (ROH)	Preferential tax rates ranging from 3% to 10%

V. Determination of Taxable Income and Deductible Items

5.1 Principles for Calculating Taxable Income

According to Section 65 Ter of the Revenue Code, taxable income is calculated based on net profit adjusted in accordance with accounting standards, and further adjusted by adding or subtracting items specified under tax law. The main categories are:

Item Type	Examples	Tax Treatment
Non-deductible Items	Expenses with informal receipts, personal expenditures, tax penalties	Must be added back to profit
Deductible Items	Salaries and wages, social security contributions, legitimate depreciation, rent, travel expenses	May be claimed as business expenses
Special Deductible Items	Qualified donations (up to 2% of net profit), R&D expenses, employee training	Deductible at double the actual amount under specific incentives
Loss Carryforward	Tax losses incurred in prior years (up to five years)	Deducted against future taxable profits

VI. Filing Obligations and Timeline

Filing Type	Reporting Period	Summary of Filing Content	Deadline
PND 51	Mid-fiscal year	Mid-year advance payment based on estimated profit	Within 2 months after mid-year end
PND 50	End of fiscal year	Annual profit calculation, audited financial statements, deduction details, and attachments	Within 150 days after fiscal year end
Nil Filing	End of fiscal year	PND 50 must still be submitted even if there is no income or a loss	Same as above

VII. Common Compliance Risks and Mitigation Recommendations

Risk Area	Consequences	TMA Recommendation
Failure or delay in filing	Penalty (up to THB 200,000)	Plan schedules in advance with systematic reminders
Improper treatment of depreciation and accruals	Taxable profit re-assessed by the Revenue Department	Maintain a fixed asset register and conduct annual reviews
Use of non-compliant invoices	Expenses disallowed; profits artificially inflated	Accept only formal tax invoices
BOI project not separately accounted	Tax exemption revoked; back taxes imposed	Set up separate accounting for BOI and non-BOI activities
Non-disclosure of related-party transactions	Violation of transfer pricing rules; subject to significant fines	Prepare TP documentation and disclose on time

VIII. TMA’s Tax Compliance Services

TMA Consultant Management Co., Ltd. provides comprehensive corporate income tax compliance services, including:

Financial statement auditing and pre-tax simulation
Annual and mid-year CIT return filing (in Chinese, English, and Thai)
Accounting and audit support for BOI enterprises
Transfer Pricing (TP) documentation preparation and submission
Taxpayer health checks and remediation of past compliance issues
Handling of tax audits and preparation of negotiation documentation

IX. Conclusion

Corporate income tax management is a systematic process that involves legal interpretation, accounting practices, invoice control, and audit coordination.

TMA is dedicated to offering professional, standardized, and efficient services to help both local and foreign enterprises establish stable and compliant tax structures in Thailand, ensuring sustainable business operations while minimizing tax-related risks.

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Disclaimer

TMA Consulting Management has been paying attention to the updating of information through newsletters for many years, but we do not assume any responsibility for the completeness, correctness or quality of the information provided. No information contained in this article can replace the personal consultation provided by a qualified lawyer. Therefore, we do not assume any liability for damages caused by the use or non-use of any information in this article (including any kind of incomplete or incorrect information that may exist), unless it is caused intentionally or by gross negligence.