TL;DR:Thailand’s PIT is clearly progressive: marginal rates from 0% up to 35% across eight bands (exempt to >THB4,000,000), with deductions and special rules affecting final tax.
Thailand uses a strongly progressive personal income tax (PIT) scale: marginal rates rise from 0% to 35% so higher earnings pay a larger share. Current resident individual brackets (THB taxable income) are: 0–150,000 exempt; 150,001–300,000 5%; 300,001–500,000 10%; 500,001–750,000 15%; 750,001–1,000,000 20%; 1,000,001–2,000,000 25%; 2,000,001–4,000,000 30%; over 4,000,000 35%. These are marginal rates: only the income in each band is taxed at that band’s rate. Deductions, allowances and special rules (for seniors, non‑residents, dividends, etc.) change effective tax paid. The structure is set by the Thai Revenue Department and is consistent in recent years; OECD and major tax firms summarise the same bands. For official detail and interactive examples, consult the Thai Revenue Department guidance and a current tax brief from a Big Four firm before planning or filing.
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