What to file after a Thailand BOI certificate, and what missing it costs

01Why the certificate is the start, not the end

Plenty of companies treat the promotion certificate from the Board of Investment (BOI) as the point where the project is finished, put it in a drawer and go back to running the factory. It works the other way round. The incentives are advanced to the company up front, in exchange for continuous reporting and supervision. If the company does not hold up its end, the incentives can be taken back — and what has already been used can be recovered.

The certificate is not a switch that turns tax off either. However complete the registration is on the BOI side, the corporate income tax exemption under section 31 of the Investment Promotion Act only lands if the exemption schedule is filled in correctly in the annual corporate income tax return (PND.50) each year. Both ends have to be right before the incentive is actually realised.

02Quarterly and annual reporting are two separate lines

After the certificate is issued there are two reporting lines. They run in parallel, they are timed separately, and neither substitutes for the other.

• The quarterly project progress report. While the project is under construction, four items are reported each quarter: land, factory building, machinery and first revenue. It has to be filed within the prescribed period after each quarter end — the period in force is whatever BOI's current announcement says (notices of the ป.8/2569 type), and the direction of travel in recent years has been to tighten it. The obligation ends once the operating licence is in hand.
• The annual report on company operating results. This one covers every certificate holder, including companies already in operation. It is filed on a fixed calendar date each year and covers shareholder information, financial statements, corporate income tax filing material, employment data and standards certification. As long as the certificate exists and the incentives are being used, it is due every year. There is no graduating out of it.

The two mistakes companies make most often. A quarter with no imports and no construction work still has to be filed, with zero progress reported honestly — nothing happening is not the same as nothing to file. And being in production does not mean the reporting is over: the quarterly line ends, the annual line continues.

03Two more deadlines, counted in months from the certificate

Beyond the two reporting lines there are two windows, both anchored to the date the certificate was issued.

• The machinery import window. Machinery that is to come in free of import duty has to be imported within the deadline. Overrun it and the duty exemption on that machinery is directly affected, with the duty becoming payable. There is a formal extension procedure.
• The window to start operations. Slightly longer than the machinery window. It tests whether the project has genuinely been built and brought into production, and overrunning it directly affects the corporate income tax exemption — one of the heaviest items in the BOI package. An extension can be applied for, but it has to be started ahead of time.

Some certificates also carry a case-specific condition on earning first revenue by a certain date. Not every project has one, so read the terms of your own certificate word by word instead of borrowing another company's experience — see what to look at first on a new certificate.

One more common error: do not work out how often you have to report from the older wording printed on the certificate. BOI rules move with each new announcement, and the cadence and deadline of the quarterly report have been tightened before. Go by the current official announcement, always.

04What one missed filing sets off

BOI's electronic entitlement systems are linked to one another, so the chain runs longer than most companies expect. One report is missed; the electronic entitlement system is suspended; that hits the duty-free release of the machinery and raw materials you are relying on right now, so even a genuinely urgent import can be held up; foreign expert visa and work permit processing is affected next; and where reports are missed repeatedly, part or all of the promoted status can be withdrawn and the corporate income tax and duty-free import benefits already taken can be recovered — under the penalty provisions of the Investment Promotion Act, with a surcharge added, the section numbers being as stated in the official text. On the raw materials side there is a separate reconciliation deadline; leaving it unreconciled for a long time affects the right to import later.

One technical detail. BOI notices normally go to the contact email address registered in the system. Even if that is an old mailbox nobody reads any more, the notice may still count procedurally as delivered. Putting someone in charge of watching system notices belongs in your internal rules, not in the post-mortem after something has gone wrong.

05How to set this up

Take the date the certificate was issued as the anchor and put the whole set into an internal calendar in one go: the quarterly deadlines, the fixed annual date, the machinery import window and the operating window. Have finance or compliance own the filing ledger, with the engineering and HR lines feeding it, and keep your own buffer ahead of the official deadlines. If something is running late, start the extension application while there is still time rather than trying to repair it after the date has passed.

Certificate terms vary a great deal by batch, by industry and by the nature of the project, so the periods described here are directional. The obligation list on your own certificate, the exact day each deadline falls on and whether an extension is available have to be checked line by line by our advisers against the original certificate, your actual accounts and your actual progress. See also what has to be reported each year and what the BOI engagement covers.