New to Thai accounting? The deadlines every business owner should know
One of the biggest surprises for new company owners in Thailand is how much of accounting here happens monthly. Miss a month and the penalties and interest start quietly stacking up. So here's the relaxed version of the calendar — what needs filing, roughly when, and why.
Every month
- Withholding tax returns (PND 1, 3, 53) — if you paid salaries, or paid certain services like rent, freelancers or contractors, you likely withheld tax from those payments. It must be sent to the Revenue Department, generally by the 7th of the following month (a little later if you file online).
- VAT return (PP 30) — if your company is VAT-registered, you file every month by the 15th (again, slightly later online) — even in months with zero sales. Zero-activity months still need a filing. This one catches a lot of seasonal island businesses out.
- Social Security (SSO) — if you have employees, contributions are due monthly, by the 15th of the following month.
Twice a year
- Half-year corporate income tax (PND 51) — an estimate of your full-year profit, filed within 2 months after the first six months of your accounting year. Seriously under-estimating can trigger penalties, so it's worth doing thoughtfully.
Once a year
- Annual audited financial statements — every Thai limited company, no matter how small or quiet, must have its accounts audited by a licensed auditor each year. Yes, even a dormant company.
- Annual corporate income tax return (PND 50) — filed within 150 days of your financial year end (for a December year-end, that means late May).
- Filing with the DBD — the audited financial statements also go to the Department of Business Development, and an annual general meeting must approve them first (within 4 months of year end).
- Personal income tax (PND 90/91) — for you and your employees, filed by the end of March for the previous calendar year (longer online).
What happens if you miss a deadline?
Nothing dramatic on day one — which is exactly why it's dangerous. Fines and monthly interest surcharges accumulate quietly in the background, and unfiled periods pile up. We regularly meet owners who didn't know their company had obligations while "not really trading", and are facing several years of catch-up filings at once.
The good news: once a proper monthly rhythm exists, none of this is stressful. It's a short checklist, done on time, every month — and then you get back to the beach.
Rule of thumb: if money moved — in, out, or to staff — something probably needs filing next month. When in doubt, ask.