BOI Accounting in Thailand.

BOI accounting in Thailand: why promoted companies keep different books

BOI accounting in Thailand exists because the incentive is narrower than the company. The Board of Investment's headline benefit is exemption of corporate income tax on the net profit and dividends derived from the promoted activity, not from everything the company does. A promoted company that also earns non-promoted revenue, trading income, or income outside its certificate's scope has to be able to show which profit is which, so its books are set up from the start to keep promoted and non-promoted activity apart: revenue, costs, and the allocations between them.

That is the accounting execution layer. What incentives a project can get, and how to structure for them, is its own advisory question, covered on BOI tax incentives; how to obtain promotion in the first place is walked through in the BOI promotion guide. This page is about running the numbers once the certificate exists.

None of it replaces normal Thai compliance. A promoted company still files its corporate income tax returns with the Revenue Department on the standard calendar, the annual return within 150 days of the accounting period's close, so BOI reporting always runs alongside the ordinary one, never instead of it.

Using the exemption is an application, not a default

The corporate income tax exemption is not something a promoted company simply nets off its return. The BOI's guide sets out a distinct process for applying to use the incentive: the company prepares the supporting materials, files the information into the BOI's e-Tax system, has the application considered by a certified accounts auditor, attaches the report of the auditor's opinions, and submits the package to the Office of the BOI.

That auditor step is why BOI accounting and audit work sit so close together. The statutory audit already examines the annual financial statements; the incentive application asks an auditor to stand behind the promoted-activity figures specifically. Books that never separated promoted from non-promoted activity make that opinion hard to give, and untangling a year of mixed records after the fact costs more than structuring the ledger correctly in month one.

The certificate's conditions stay live throughout. The BOI supervises compliance with project conditions, and its guide lists cancellation or partial withdrawal of rights and benefits among its monitoring functions, so condition reporting is not paperwork to backfill later. What a breach costs in a specific case is something a firm confirms; the safe assumption is that benefits can be cut back or withdrawn.

When to hand BOI accounting to a firm

A promoted company is running two compliance systems at once, and the expensive mistakes are structural: mixed books that cannot prove which profit was promoted, missed e-Monitoring windows, an incentive application an auditor cannot sign. Accounting firms in Thailand with BOI experience price this as a recurring engagement, so compare what the scope covers: the ledger design, the quarterly reporting, the year-end dual close, and the incentive application itself. Where a certificate condition is already in dispute rather than merely due, that conversation belongs with advisors, not the bookkeeper.

This page is general information, not legal advice. Rules, conditions, and procedures change; for a specific project, speak with a qualified professional.