Educational Information Only
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PND.90 / PND.91 — Personal Income Tax Return
The annual personal income tax return filed by individuals resident in Thailand. PND.91 is used by salaried employees with employment income only; PND.90 is used by anyone with mixed income (business, rental, dividends, foreign-source remitted) including self-employed persons and sole traders.
When Used
Filed annually by 31 March for the previous tax (calendar) year — extended to 8 April for e-Filing in recent years. Anyone tax-resident in Thailand for 180 days or more during the tax year, and earning Thai-source income (or, since 1 January 2024, remitting foreign-source income earned while tax-resident), must file. Filing is required even if no tax is due — Revenue uses the return to claim back over-withheld tax or to flag a non-filing case. Joint-spouse filings are permitted but increasingly rare; separate filings are simpler.
Who Files
The individual taxpayer (Thai or foreign tax-resident). Foreigners with work permits and a Thai employer normally file PND.91 with the assistance of the employer's HR department; freelancers and business owners file PND.90.
Fee & Logistics
Free to file. Tax due is paid as part of the filing.
Filing is instantaneous online; refund processing (where over-withheld tax is reclaimed) typically 30–90 days; paper filings take longer.
Online via the Revenue Department e-Filing portal (rdserver.rd.go.th); in person at any Area Revenue Office; through a licensed tax preparer.
Filing Method
- Online via e-Filing (rdserver.rd.go.th)
- Revenue Department mobile app (RD Smart Tax)
- In-person at any Area Revenue Office
- Through a licensed tax preparer
Required Documents
- 50 Bis withholding tax certificates from each employer / payer
- Investment income statements (dividends, interest, fund distributions)
- Rental income records and supporting expense receipts
- Business income & expense records (for PND.90)
- Donation receipts (certified to qualify for deduction)
- Insurance and provident-fund premium statements
- Mortgage interest certificate from the bank (for housing deduction)
- Spouse and dependent details (ID numbers, dates of birth)
Field-by-Field Walkthrough
Taxpayer Identification
(ข้อมูลผู้เสียภาษี)Tax ID (or 13-digit ID for Thais; pink-card ID or tax ID for foreigners), full name, date of birth, address, contact details.
Filing Status
Single, married filing jointly, married filing separately. Affects allowances and brackets.
Income from Employment (Category 40(1) & 40(2))
Salary, bonuses, commissions, benefits-in-kind. Totals from all 50 Bis certificates.
Other Income Categories (PND.90 only)
Category 40(3)–(8): goodwill/royalties, interest/dividends, rental, professional fees, contract work, business income. Each category has its own deduction rules.
Allowances and Deductions
(ค่าลดหย่อน)Personal allowance (THB 60,000), spouse, children, parents, life insurance, RMF/SSF, donations, mortgage interest, etc. Each has limits and supporting-document requirements.
Withholding Tax Credit
Total tax already withheld at source by employers and payers — deducted from the tax liability to arrive at net tax due or refund.
Tax Computation
Progressive bracket calculation (0% to 35%) applied to net taxable income.
Payment / Refund Details
If tax due, payment via QR, bank transfer, or counter. If refund due, Thai bank account for direct deposit (must be in taxpayer's name).
Common Mistakes
- Foreigners assuming the 180-day rule means 'consecutive' — it is cumulative within the tax year.
- Failing to declare foreign-source income remitted in the same tax year of earning (post-2024 rule change).
- Claiming RMF/SSF deductions without holding for the required minimum period — leads to clawback.
- Ignoring small interest/dividend income because withholding was already 15% — the 'final withholding' option must be actively elected.
Legal Basis
Revenue Code, Section 56 (annual filing obligation); Section 41 (residency rule and 180-day test); Revenue Department Order Por. 161/2566 (2023) on remitted foreign income.
Penalty for Non-Compliance
Late filing: surcharge of 1.5% per month on unpaid tax plus a fine of up to THB 2,000 per Section 35; deliberate evasion: criminal penalties under Section 37 including imprisonment up to 7 years.
This walkthrough summarises the practical filing requirements for a Thai government form as a starting point. Fees, procedures, and required documents change without notice — always verify with the issuing authority before filing. Educational use only; not a substitute for advice from a Thai-qualified lawyer, accountant, or licensed visa agent.
Professional Legal Assistance
When a matter involves investigation, arrest, detention, litigation, or regulatory action, professional legal representation becomes essential.
Anglo Siam Legal provides experienced legal services across Thailand for both Thai nationals and foreigners.
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