Annual compliance is a sequence, not a single filing
Year-end compliance for a Thai limited company is a strict, ordered process. You cannot simply file your taxes in one go; each filing depends on an independent audit and formal shareholder approval before it.
Dormant companies are not exempt. Even with zero revenue or operations that have not started, you complete the same audit and filing steps every year or face heavy penalties and the risk of losing your license.
The timeline below assumes the standard 31 December year-end.
The annual compliance timeline
Each step is a prerequisite for the next. Miss a deadline early and the rest of the schedule compresses, triggering automated fines.
- Close books and CPA audit (January to March)Your accountant finalizes the general ledger and trial balance. An independent licensed Thai CPA then audits the statements and issues a formal opinion.
- Annual General Meeting (by 30 April)The board holds an AGM where shareholders approve the audited statements and director lineup, within four months of the fiscal year-end.
- Government filings (14 to 30 May)File the updated shareholder list (Bor.Or.Chor.5) with the DBD within 14 days of the AGM, and upload the audited statements to the DBD portal within one month of the AGM.
- Corporate income tax, PND 50 (by 30 May; e-filing 7 June)File the annual CIT return and pay any liability. The legal deadline is 150 days from your fiscal year-end.
The mid-year obligation (PND 51)
Thai companies also file a half-year interim return, which catches many foreign founders off guard.
- The requirementFile PND 51 within two months after the first six months of your accounting period, by 31 August for calendar-year companies.
- The methodUnless you are a listed company or bank, you estimate full-year net profit and prepay 50% of the calculated tax.
- The 25% ruleIf actual year-end profit exceeds your mid-year estimate by more than 25% without good reason, the Revenue Department adds a 20% surcharge on the underpaid portion.
Corporate tax rates for SMEs
Thailand uses a tiered system that favors SMEs, defined as companies with under THB 5 million in paid-up capital and under THB 30 million in annual revenue.
- Net profit THB 0 to 300,0000%, exempt (SME).
- Net profit THB 300,001 to 3,000,00015% (SME).
- Net profit over THB 3,000,00020% (SME).
- Non-SME companies20% on all profit.
What non-compliance costs
The Revenue Department tracks filings digitally and applies penalties automatically.
- Late filing finesUp to THB 2,000 per missing form, to both the DBD and the Revenue Department.
- Interest surcharge1.5% per month on unpaid or underpaid year-end tax, from the original due date until settled.
- Operational gridlockNon-compliance blocks work-permit renewals and visa extensions for foreign employees.
Mandatory monthly filings
On top of the annual cycle, specific forms and payments go to the Revenue Department and Social Security Office every month.
- VAT, PP30 (by the 23rd)Mandatory once annual gross revenue exceeds THB 1.8 million, or if you registered voluntarily. 7% of net monthly sales (output VAT minus input VAT).
- Withholding tax, PND 1/3/53 (by the 15th)Withheld on salaries, services, and rent. Progressive on salaries (PND 1); 3% on domestic services (PND 3 and 53), 5% on office rent, 1% on transport.
- Social Security, SPS 1-10 (by the 15th)5% of gross salary, capped at THB 750 per employee, with a matching 5% (up to THB 750) from the employer.
The monthly rhythm
Missing one monthly filing triggers compounding fines. Keep your accounting team to this cadence.
- Days 1 to 5, collect documentsGather tax invoices, input VAT receipts, withholding certificates, and payroll logs from the previous month.
- Days 6 to 12, reconcile and prepareReconcile bank statements, compute the VAT differential (PP30), extract withholding sums (PND 1/3/53), and calculate SSO matching.
- By the 15th, file WHT and SSOSubmit PND 1/3/53 and SPS 1-10.
- By the 23rd, file VATSubmit PP30.
We run every engagement on a shared calendar, request documents at the start of the month, review by mid-month, and file with at least a day of buffer. The audit and monthly filings are handled end to end, so nothing slips.