Thailand Corporate Income Tax (CIT): Rates and Filing — PND50 and PND51

In short

Under the Thai Revenue Code, a limited company, public limited company, or juristic partnership established under Thai law, together with a company established under foreign law but conducting business in Thailand, must pay corporate income tax on its net profit (Section 66, Section 65); two filings are required each year — the half-year PND51 (Section 67 bis) and the annual PND50 (Section 68). The applicable rate follows the official Tax Rate Schedule / Royal Decree (Section 67), and our firm can help confirm it.

1. Who must pay corporate income tax (Section 66)

Under Section 66, the following persons must pay corporate income tax under this Part:

A company or juristic partnership established under Thai law.
A company or juristic partnership established under foreign law but conducting business in Thailand.
A person established under foreign law and conducting business in several countries (including Thailand) pays tax only on the net profit from business conducted in Thailand; if that net profit cannot be calculated, the assessment provisions apply by analogy as prescribed by law (Section 66).

2. The tax base is “net profit” (Section 65)

Corporate income tax is levied not on turnover but on net profit. Under Section 65:

Net profit = income from business during the accounting period, less the expenses deductible under the conditions specified in Section 65 bis and Section 65 ter.
The accounting period is in principle fixed at 12 months; a newly established company, or one that changes its closing date with the approval of the Director-General, may have a period shorter than 12 months (Section 65).
Income and expenses use the accrual basis: income arising in the period is included in that period even if not yet received, and the related expenses are included in that period even if not yet paid (Section 65).

3. Limits on deductible expenses (Section 65 bis, Section 65 ter)

The calculation of net profit must comply with the statutory deduction conditions and the list of items that “shall not be deemed to be expenses”:

Section 65 bis: depreciation and deterioration are deducted according to the principles, methods, conditions, and rates prescribed by Royal Decree; for a transfer of property, provision of services, or lending of money made without consideration or at a price markedly below market value without reasonable cause, the assessment official may assess it at market price; assets/liabilities in foreign currency are converted into baht at the prescribed rate; and closing inventory is valued at the lower of cost or market price (Section 65 bis).
Section 65 ter: the following shall not be deemed to be expenses — the various reserves (except as allowed by law), expenses of a personal nature and gifts/charitable donations (except within the statutory limits), tax penalties and surcharges for late payment, criminal fines, corporate income tax itself, and value added tax that is non-creditable under the rules, among others (Section 65 ter).

4. How the tax rate is determined (Section 67)

Section 67 provides that corporate income tax is paid at the rate specified in the “Tax Rate Schedule” at the end of this Chapter. In other words, the rate applicable to ordinary companies, as well as the preferential rate for small and medium-sized enterprises (SMEs), is set separately by the Tax Rate Schedule / Royal Decree.

⚠️ About the rate figures

The standard corporate income tax rate, and the tiered/progressive preferential rates for small and medium-sized enterprises (SMEs), are set by Royal Decree and are adjusted in line with policy, so this article does not list specific figures; the actual applicable rate should be taken as prescribed by the Thai authorities (our firm can help confirm it).

Special case: a foreign enterprise engaged in cross-border transport under the second paragraph of Section 66 pays tax at 3% on the passenger fares it charges in Thailand and on freight charges, respectively (this rate is expressly set out in Section 67).

5. Two filings: the half-year PND51 and the annual PND50

For each accounting year, a company must file and pay tax to the tax authorities twice:

Half-year PND51 Section 67 bis

Within two months after the end of the first six months counting from the first day of the accounting period, the return is filed and the tax paid. An ordinary company is taxed on half of its estimated net profit for the full year; a listed company, a bank, or a finance and securities company, and the like, is taxed on the actual net profit of that six-month period (Section 67 bis).

Annual PND50 Section 68

Within 150 days from the final day of the accounting period, the return needed to calculate the tax is filed and the tax paid (Section 68). The tax already paid for the half-year period can usually be credited at the annual filing.

Dissolution and liquidation filing Section 69

When a company is dissolved and liquidated, the liquidator and the manager remain responsible for filing and paying tax; if the return cannot be filed within the deadline, they may apply to the Director-General for an extension within 30 days from the date the tax authority receives the registration of dissolution (Section 69).

⚠️ Tip

Corporate income tax involves several steps — net-profit adjustments, the deductibility of expenses, the half-year estimate, and the annual reconciliation — and must be handled case by case in light of the company’s actual accounts. Our firm can help prepare the accounts, calculate the tax, and file the PND51/PND50 on your behalf.

FAQ

Who must pay corporate income tax (CIT) in Thailand?

A company or juristic partnership established under Thai law, as well as one established under foreign law but conducting business in Thailand, must pay tax; a foreign company operating in several countries (including Thailand) pays tax on the net profit from the business it conducts in Thailand (Section 66).

What is the tax base for corporate income tax?

The tax base is “net profit” — income from business during the accounting period, less the expenses deductible under Section 65 bis and Section 65 ter; the accrual basis is used, and the accounting period is in principle 12 months (Section 65).

What is the corporate income tax rate in Thailand?

Section 67 provides that tax is paid at the rate specified in the Tax Rate Schedule at the end of the Chapter. The standard rate and the preferential rates for SMEs are set separately by Royal Decree and adjusted in line with policy; this article does not list specific figures, and the actual applicable rate should be taken as prescribed by the Thai authorities (our firm can help confirm it).

How many times a year must you file, and when are the deadlines?

Two filings are required: the half-year PND51 is filed within two months after the end of the first six months counting from the first day of the accounting period (Section 67 bis); the annual PND50 is filed within 150 days from the final day of the accounting period (Section 68).