Thailand Tax Calendar: Deadlines That Matter to Expats
Thai penalties run at 1.5% per month on late amounts plus fixed fines. Bookmark this page — dates repeat every year.
The annual cycle
| Date | What's due | Who cares |
|---|---|---|
| March 31 | P.N.D.90/91 annual personal return (paper) | Everyone with assessable Thai income |
| April 8 | Same return via e-Filing (automatic 8-day extension) | Everyone — just file online |
| April 30ish | Late-filing window closes; surcharges start running | Procrastinators |
| September 30 | P.N.D.94 half-year return | Filers with assessable income types 5–8 (freelance, rental, etc.) expecting >60k THB net half-year income after allowances |
| Ongoing: day 90 | Immigration 90-day address report | Every long-stay foreigner (not tax but the fine is real: 2,000 THB) |
P.N.D.94: the one that surprises freelancers
If you earn freelance/rental/investment income (income types 5–8), Thailand wants estimated tax mid-year. The catch that makes it painless: half-year tax paid is credited against your annual bill. If your annual filing shows you overpaid, it comes back. Filing it avoids a year-end surcharge for under-withholding.
Penalty structure
- Late payment: 1.5% surcharge per month on unpaid tax + potential fixed fine (2,000+ THB)
- Late filing with zero owed: smaller fixed penalty — always better to file even if broke
- Incorrect returns flagged in audit: additional penalties scale with intent findings
Beyond tax: the expat admin calendar
| Recurring item | Cadence |
|---|---|
| 90-day report | Every 90 days of continuous stay (online/agent/in-person) |
| Visa extension | Annual before current stamp expires (100–1,900 THB) |
| Driving license renewal | 1st: 1yr → then 5yr terms |
| Health insurance renewal | Annual — don't let it lapse; reinstatement is harder than renewal |
Preparing to file? Estimate your bill → · Check if you must file at all: decision guide →
Dates verified against Revenue Department announcements for calendar year 2026. Government holidays shift exact dates by days — confirm during filing season.
Content last reviewed: August 2026.