The Thailand Securities and Exchange Commission has revised the criteria for identifying major shareholders of securities and digital asset business operators that require approval, expanding the scope to better reflect ultimate controlling persons. The amended rules took effect on 4 March 2026 and require affected business operators to reassess their major shareholder status and seek approval for individuals who now fall within scope. Key changes include an updated definition of “major shareholders” to include controlling persons, an additional pro rata method for assessing indirect shareholdings, and specified indicators of controlling power that capture holdings and influence via a spouse (including a cohabiting couple), minor children, and persons acting in concert or otherwise coordinating voting rights as prescribed by the SEC. The SEC issued the related regulations and published them in the Royal Gazette, following a public hearing conducted in January 2026. Transitional provisions require business operators to submit approval requests within 180 days from the 4 March 2026 effective date for any individuals who meet the revised criteria and were not previously approved under the former framework.