Foreign-owned companies operating in Thailand need a reliable monthly accounting process, appropriate tax filings, annual financial statements and—where required—statutory audit coordination.
The exact obligations depend on the legal entity, business licence, VAT status, employees, related-party transactions, overseas payments and accounting period. A foreign shareholder does not remove the company's Thai accounting and tax responsibilities.
1. Start with the legal and operating profile
Before choosing a bookkeeping process, document the company's profile. Confirm the legal form, foreign ownership percentage, operating permission, actual business activities, accounting year-end, VAT status, employees, overseas payments, intercompany arrangements, currencies and any BOI or FBL conditions.
This prevents a common error: copying a compliance calendar from another company whose ownership, licence or transactions are different.
2. Maintain complete Thai accounting records
The bookkeeping system should be designed around the company's real transactions. A monthly close normally includes sales and purchase invoices, receipts, credit notes, bank reconciliations, petty cash, fixed assets, inventory or project costs, payroll, shareholder funding, foreign-currency balances, accruals, prepayments and related-party schedules.
Each entry should be traceable from the ledger to an underlying document and payment trail. WMC can provide an English management summary while retaining the Thai statutory ledger and supporting records required for local compliance.
3. Understand the main tax filing workstreams
Corporate income tax
Companies carrying on business in Thailand generally need to manage annual corporate income tax and any applicable interim tax requirements. The Revenue Department provides company tax return forms P.N.D.50 and P.N.D.51. Its English guidance states that the annual return is filed within 150 days from the closing date of the accounting period; confirm the current rule and filing route before submission. Revenue Department: Corporate Income Tax
Value added tax
A company liable to VAT must consider registration, tax invoices, output VAT, input VAT and monthly reporting. The Revenue Department states that a VAT return is submitted with payment, if any, by the 15th day of the following month, subject to the applicable filing method and current rules. Revenue Department: Value Added Tax
Withholding tax
When a Thai company pays certain types of income, it may need to withhold tax, issue a certificate and file the appropriate return. The Revenue Department lists P.N.D.1, P.N.D.3 and P.N.D.53 among the withholding tax forms. Payments to overseas recipients require review of the contract, service, place of performance, treaty position and supporting evidence. Revenue Department: Withholding Tax
Payroll-related filings
If the company employs staff in Thailand, payroll should be reconciled with employment contracts, employee tax withholding and social-security processes. Directors' fees, expatriate compensation and reimbursements may require separate review.
Quick-reference filing calendar
The table below is a planning aid, not a substitute for the current Revenue Department calendar. Dates can vary where a filing is electronic, a public holiday changes the due date or a special extension applies.
| Form / return | What it generally covers | Typical timing |
|---|---|---|
| P.N.D.1, P.N.D.3, P.N.D.53 | Monthly withholding tax | Usually the 7th; eligible e-Filing commonly the 15th of the following month |
| P.P.30 | Monthly VAT return | Usually the 15th; eligible e-Filing commonly the 23rd of the following month |
| P.N.D.51 | Half-year corporate income tax | Within two months after the first six months of the accounting period |
| P.N.D.50 | Annual corporate income tax | Within 150 days from the accounting year-end |
For current dates, check the official Revenue Department Tax Calendar. It is currently presented in Thai and updated by month; the official Thai calendar and later announcements prevail over this English summary.
4. Prepare annual financial statements and DBD filing
The annual close is more than a tax calculation. The company should finalise balances, obtain audit support where required, prepare financial statements and complete the relevant filing with the Department of Business Development (DBD).
DBD provides an electronic service for submitting financial statements and shareholder information. The year-end checklist should include bank, customer, supplier and intercompany reconciliations; fixed assets; inventory; accruals; foreign-currency balances; shareholder loans; related-party disclosures; tax reconciliation; approval; signing; and electronic submission. DBD online services and e-Filing
5. Use the appropriate Thai financial reporting framework
Financial statements are prepared under the Thai financial reporting framework applicable to the entity. The Federation of Accounting Professions publishes Thai Accounting Standards and Thai Financial Reporting Standards (TAS/TFRS), including standards based on IFRS with Thai applicability. A parent company's IFRS reporting pack may support management reporting but does not automatically replace Thai statutory financial statements. TFAC: Thai Financial Reporting Standards
6. Coordinate the audit early
Audit coordination is most efficient when it starts before year-end. Agree the timetable, trial balance, lead schedules, material contracts, related-party information, confirmations, inventory procedures, management representation and final signing steps.
WMC can coordinate accounting records and documentation with an appropriate audit partner. The audit opinion is issued by the appointed audit professional; WMC should describe this service accurately as audit coordination or support unless it is the legally appointed auditor.
7. Make the process work for an overseas parent
Foreign-owned companies often need two reconciled views of the same data: Thai statutory compliance and management or group reporting. A documented mapping between the Thai chart of accounts and the parent's reporting chart reduces repeated work and makes month-end review easier.
8. Records, controls and handover
Create a shared document structure for sales, purchases, bank, payroll, tax, fixed assets, contracts, related parties and year-end support. Good controls include separate payment preparation and approval, a monthly close checklist, a tax calendar, an open-issues register and a secure process for confidential financial data.
Practical first-year checklist
Set up
Confirm entity, ownership, permissions, accounting period, registrations and reporting currency.
Close monthly
Collect documents, reconcile balances, review VAT and withholding tax and prepare management reporting.
Prepare year-end
Resolve missing records, prepare schedules, coordinate audit support and finalise statements.
File and retain
Confirm approval, signing, DBD and Revenue Department submission steps and archive evidence.
Common mistakes to avoid
- Assuming no sales means no filing or annual compliance.
- Relying only on a foreign parent's books without maintaining Thai records.
- Treating every payment to a foreign supplier the same way.
- Expecting the auditor to reconstruct incomplete monthly bookkeeping at year-end.
Frequently asked questions
Does a foreign-owned company need a Thai accountant?
The company needs accounting records and filings that comply with Thai requirements. The work may be performed internally, outsourced or combined, provided responsibility and signing arrangements are clear.
Can our parent company use its own accounting software?
Yes, if the process produces complete, traceable records and supports Thai statutory reporting. Many companies use a Thai ledger plus a reconciled group-reporting pack.
Do we need VAT registration immediately?
Not every company has the same VAT position. Registration depends on activities and applicable Revenue Department rules. Review the position before invoicing customers.
What are P.N.D.50 and P.N.D.51?
They are Revenue Department company income-tax return forms. Filing obligations and timing depend on the accounting period and company circumstances.
Is an audit always required?
Audit requirements depend on the company's legal form and applicable Thai rules. Confirm the requirement and appointment process at the start of the financial year.
Can WMC perform the statutory audit?
WMC can support records, schedules and communication with an appointed audit partner. The appointed audit professional is responsible for the audit opinion.
Can WMC report in English?
Yes. Local compliance work can be accompanied by English monthly reports, management commentary and schedules mapped to an overseas parent's reporting format.
What should we do if the previous accountant left incomplete records?
Begin with a structured diagnostic, obtain the latest trial balance and filings, identify missing periods, reconcile opening balances and agree a catch-up plan before submitting new returns.
Official Sources and Further Reading
- Revenue Department: Corporate Income Tax
- Revenue Department: Value Added Tax
- Revenue Department: Withholding Tax forms
- Revenue Department: Tax Calendar (Thai-language official page)
- Department of Business Development: Online services and e-Filing
- Federation of Accounting Professions: Thai Financial Reporting Standards
How WMC Can Help
WMC provides English-supported accounting and tax coordination for companies operating in Thailand, including monthly bookkeeping, tax filing preparation, payroll and withholding-tax support, year-end closing, audit coordination and English management reports.
Start with a short review of your entity, transactions, tax registrations and reporting needs. We will identify the information required and propose a practical scope before work begins.
Discuss Your Thailand Accounting Requirements
Contact WMC to discuss bookkeeping, tax filing, financial statements or audit coordination for your company.
Discuss your requirementsEmail WMCImportant note: This article is general information, not legal, tax or audit advice. Thai requirements can change and the correct treatment depends on the company's facts, contracts, registrations and applicable rules. Obtain a current review from a qualified Thai accounting or tax professional before relying on this information.