Can a foreigner own 100% of a company in Thailand?

Yes, but only through three routes: BOI promotion, a US citizen using the Treaty of Amity, or a Foreign Business License. Outside these, foreign ownership of a Thai limited company is capped at 49% for most business activities, with the majority held by Thai shareholders.

What We See In Practice

Is using nominee shareholders really necessary in Thailand, and how can a foreigner legally maintain control of a company despite the 49% foreign ownership limit?

Most people who come to us have already been told by someone in a bar that ‘everyone just uses nominees’. In ten years, every nominee structure we have been asked to unwind cost far more to fix than doing it correctly would have cost on day one. The 49% cap is also not the obstacle people assume: with the right share structure, a minority foreign shareholder can keep control of the company legally.
BOI promotion is the route most of our clients end up taking. If your activity qualifies, you own 100%, you skip the four-Thai-employees-per-work-permit rule, and you get tax incentives on top. The application takes longer than a standard registration, but for tech, services and manufacturing businesses it is usually worth the wait.
If BOI does not fit, a properly drafted shareholding with preference shares and weighted voting rights lets you hold 49% and still control decisions and dividends. That structure is legal. Paying two Thai strangers to hold shares for you is not.