Tax Planning for Growing Companies in Thailand: What to Review Each Year
Tax planning is not about finding loopholes. For a growing company in Thailand it means understanding the rules that apply to you, keeping records that support every deduction, and making decisions early enough that tax is part of the plan rather than a surprise at year-end.
Start with the rules that apply to your company
SME corporate income tax rates
According to the Revenue Department, a company qualifies for the SME rates when its paid-up capital at the end of the accounting period does not exceed THB 5 million and its revenue from sales and services in that period does not exceed THB 30 million. The rates on net profit are:
Net profit up to THB 300,000: exempt
THB 300,001 to 3,000,000: 15%
Over THB 3,000,000: 20%
Companies that do not meet both conditions pay 20% on the whole net profit. As your capital or revenue grows, check each year whether you still qualify, because crossing a threshold changes your tax cost.
VAT registration
A business whose regular revenue from goods or services exceeds THB 1.8 million per year must register for VAT within 30 days of exceeding the threshold. Monitoring revenue monthly helps you register on time and price your services correctly from the start.
Half-year estimated tax (PND.51)
Companies file a half-year return (PND.51) based on estimated net profit, generally within two months after the first six months of the accounting period. If the estimate falls short of actual profit by more than 25% without reasonable cause, the Revenue Department may impose a surcharge of 20% of the tax underpaid. A realistic mid-year forecast avoids this cost.
Practical planning steps
Keep proper supporting documents. Expenses are only deductible when they relate to the business and are supported by valid tax invoices, receipts and contracts.
Review monthly figures, not just year-end. A simple monthly profit report shows early whether your SME status, VAT position or half-year estimate needs attention.
Plan major purchases and investments. The timing of capital spending affects depreciation and cash flow, so discuss it before you commit.
Separate business and personal spending. Mixing them makes deductions harder to support and increases audit risk.
Check withholding tax at the point of payment. Correct withholding on services, rent and other payments avoids penalties and reconciliation problems later.
Example (illustrative only, not a client case): a service company expects revenue to rise from THB 25 million to THB 34 million next year. Planning ahead lets the owners see that the company will no longer meet the SME revenue condition, budget for the higher tax cost and adjust pricing or timing of investments accordingly.
Where tax planning ends
Good planning works within the law and reflects the real substance of transactions. Arrangements designed only to reduce tax, without a genuine business purpose, can be challenged and may lead to surcharges and penalties. When in doubt, ask before you act.
How YP can help
Our Accounting & Tax Compliance service keeps your monthly filings accurate and your figures up to date, which is the foundation of any tax plan. At year-end, our Annual Financial Closing service prepares your financial statements and PND.50. Book a consultation to review your tax position for the year ahead.
Related reading: How to Prepare Your Business for an External Audit in Thailand.
Sources
Information checked on 26 October 2026. Tax rules change; this article is general information, not tax advice for your specific situation.
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