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Practice area
Corporate Income Tax in Thailand.
Corporate income tax in Thailand: the 20% standard rate, SME bands, CIT 50 and CIT 51 deadlines, BOI exemptions, and treaty relief, with firms for each.
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Featured firms
Featured corporate income tax in Thailand
FRANK Legal & Tax
Free consultation · 15 min
Law firmBangkokEnglish · Thai · German
International boutique law firm in Bangkok and Phuket, providing legal and tax services to investors, businesses, and private clients across Thailand
฿7,000–12,000 / hour
GPS Legal
Consultation from ฿3,125 · 30 min
Law firmBangkokEnglish · Thai · Swedish
Bangkok-based law firm delivering strategic, business-focused legal advice with deep local expertise and a practical, solutions-oriented approach.
฿3,500–15,000 / hour
Key facts
- What is the corporate tax rate in Thailand?
- 20% on net profit as standard. Small companies with paid-up capital under 5 million baht pay 15% on net profit from 300,000 to 3 million baht and 20% above that.
- When are corporate tax returns due?
- The annual return (CIT 50) within 150 days of the accounting period's end; the half-year return (CIT 51) within two months after the first six months, paying half the estimated tax.
- Do foreign companies pay Thai corporate income tax?
- Only if they carry on business in Thailand. A foreign company without business activity here is instead withheld at 10% on dividends and remitted profits and 15% on most other Thai-source income, before treaty relief.
- Can the rate be reduced?
- Yes. BOI promotion can exempt corporate income tax for three to thirteen years depending on activity group, and Thailand's 57 tax treaties can reduce withholding on cross-border payments.
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Corporate income tax in Thailand: the numbers first
Corporate income tax in Thailand is charged on net profit, and the standard Thailand corporate tax rate is 20%. Small companies get a gentler curve: with paid-up capital under 5 million baht at period end, net profit from 300,000 to 3 million baht is taxed at 15%, and 20% above that.
The tax applies to Thai companies and to foreign companies carrying on business in Thailand. That phrase does a lot of work: a foreign company with no business activity here is taxed differently, through withholding on Thai-source income rather than on net profit, which is why cross-border structures need the question answered before anything else.
The filing cycle
Two returns anchor the year. The annual return (CIT 50) is due within 150 days of the closing date of the accounting period, and the half-year return (CIT 51) pays half of the estimated tax within two months after the first six months. Corporate tax filing covers the cycle in detail, including what happens when the estimate is wrong.
Both returns draw on audited books, so the tax calendar and the accounting calendar are one machine. Most companies hand the whole chain to one firm and keep the auditor separate.
All firms
All corporate income tax in Thailand
Law firmBangkokEnglish · Thai · German
YOUR ONE-STOP COORDINATOR FOR INTEGRATED LEGAL, TAX AND BUSINESS SOLUTIONS
FRANK Legal & Tax
Free consultation · 15 min
Law firmBangkokEnglish · Thai · German
International boutique law firm in Bangkok and Phuket, providing legal and tax services to investors, businesses, and private clients across Thailand
฿7,000–12,000 / hour
GPS Legal
Consultation from ฿3,125 · 30 min
Law firmBangkokEnglish · Thai · Swedish
Bangkok-based law firm delivering strategic, business-focused legal advice with deep local expertise and a practical, solutions-oriented approach.
฿3,500–15,000 / hour
MSC International Law Office
Free consultation · 30 min
Law firmBangkokEnglish · Thai · Chinese (Mandarin) · Cantonese · Russian · German
International Legal and Cross-Border Business Advisory in Thailand and Asia
Accounting firmBangkokThai · English · French
Cloud-based accounting, tax filing & payroll for businesses in Thailand. All-inclusive pricing, zero hidden fees, 24/7 online access.
GPS Accounting
Free consultation
Accounting firmBangkokEnglish · Thai · Filipino · Swedish
Full service accountancy practice registered with the Thai Federation of Accounting Professions delivering accountancy and tax services in English.
Law firmBangkokEnglish · French · Thai
International firm in Asia since 2006 — corporate legal, accounting, advisory and audit services across Thailand, China & the Philippines.
Law firmBangkokEnglish · Thai · Spanish
Experts assisting clients in conducting their businesses and protecting their rights and investments in Thailand across a wide range of legal matters.
What changes the rate
The headline 20% is the start, not the end. BOI-promoted companies can hold corporate income tax exemptions of three to thirteen years depending on activity group, some capped at the project's investment value; BOI tax incentives covers the groups and the conditions attached to the certificate.
Cross-border payments carry their own layer. A foreign company not carrying on business in Thailand is withheld at 10% on dividends and remitted profits and 15% on most other income, before treaty relief. Thailand's treaty network stands at 57 agreements, and claiming a reduced rate is paperwork with a procedure behind it: tax treaty applications for the relief itself, and international tax compliance for the recurring obligations a cross-border structure creates.
Where advice earns its fee
Rate questions are mostly lookups. Structure questions are not: whether a subsidiary or a branch fits better, how losses carry, when the SME bands are worth preserving, and what a dividend path home costs after withholding. That forward-looking work is corporate tax planning, and it pays best before the structure exists rather than after.
The wider field of firms, including who is licensed for what, is on the tax advisors in Thailand page. This page is general information, not tax or legal advice. Rates and deadlines change; for a specific company, speak with a qualified professional. The firms below list their languages, locations, and services.
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Common questions
Frequently asked questions
- How is corporate income tax calculated in Thailand?
- On net profit, at 20% as standard. A small company, defined by paid-up capital under 5 million baht at the end of the period, pays nothing on the first 300,000 baht of net profit, 15% up to 3 million baht, and 20% beyond. The calculation runs off audited financial statements, which is why the accounting close, the audit, and the tax return form one chain.
- What are CIT 50 and CIT 51?
- The two returns every company files. CIT 50 is the annual corporate income tax return, due within 150 days of the closing date of the accounting period. CIT 51 is the half-year return, due within two months after the first six months, and it prepays half of the tax estimated for the full year. A significantly wrong estimate can carry a surcharge, which is why firms treat the mid-year figure as real work rather than a formality.
- Does a foreign company owe corporate income tax in Thailand?
- It depends on whether the company carries on business in Thailand. If it does, it is taxed on net profit like a Thai company. If it does not, Thai-source income is taxed by withholding instead: 10% on dividends and remittance of profits, 15% on most other categories such as interest, royalties, and professional fees, subject to reduction under an applicable tax treaty.
- How do BOI incentives affect corporate income tax?
- A promotion certificate can exempt corporate income tax on the promoted activity's net profit for three to thirteen years depending on the activity group, with some exemptions capped at the project's investment value. The exemption applies only to the promoted activity, so the books must separate promoted from non-promoted income, and the conditions in the certificate decide what the exemption is actually worth.
- Do I need a firm for corporate tax, or can we file ourselves?
- Filing is possible in-house once the books are audited, and plenty of Thai-staffed companies do it. Firms earn their fee on the judgment calls: the half-year estimate, loss utilisation, the promoted-income split for BOI companies, and the withholding and treaty layer on anything cross-border. Compare quotes on identical scope, and ask whether responding to Revenue Department questions is included.
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