Foreign investors, comprising as per the Foreign Business Act all non-resident investors and majority-foreign owned firms incorporated in Thailand, are subject to discriminatory minimum capital requirements. Since 2019, the new Ministerial Regulation re: Minimum Capital and the Period to Bring or Remit the Minimum Capital to Thailand B.E. 2562 (2019) sets specific timelines for foreign businesses to bring or remit the minimum capital to Thailand. It applies to companies using privileges under certain treaties and trade agreements, and requires compliance by August 29, 2029. For companies not under these agreements, the regulation maintains existing capital requirements, mandating minimum capital of THB 2 million for companies not subject to a foreign business license requirement, or 25% of the average estimated expenses for three years of operation or THB 3 million, whichever is higher, for companies subject to a foreign business license requirement.
"Section 4
In this Act, “foreigner” means:
1. a natural person who is not of Thai nationality;
2. a juristic person not registered in Thailand;
3. a juristic person registered in Thailand, being of the following descriptions: 
a. being a juristic person at least one half of capital shares of which are held by persons under (1) or (2) or a juristic person in which investment has been placed by the persons under (1) or (2) in the amount at least equivalent to one half of the total capital thereof;
b. being a limited partnership or a registered ordinary partnership the managing partner or the manager of which is the person under (1);
4. a juristic person registered in Thailand at least one half of the capital shares of which are held by persons under (1), (2) or (3) or a juristic person in which investment has been placed by the persons under (1), (2) or (3) in the amount at least equivalent to one half of the total capital thereof;
For the purpose of this definition, shares of a limited company represented by share certificates issued to bearers are deemed as shares held by foreigners, unless otherwise provided by the Ministerial Regulation.
“capital” means a registered capital of a limited company or a paid-up capital of a public limited company or money invested in a partnership or a juristic person by partners or members thereof;
“minimum capital” means, in the case where the foreigner is a juristic person registered in Thailand, a capital of a foreigner; and means, in the case where a foreigner is a juristic person not registered in Thailand or is a natural person, foreign currencies brought and used by foreigners at the commencement of the operation of businesses in Thailand; [...]
[...]
Section 14
The minimum capital to be used by a foreigner for the commencement of the operation of a business in Thailand shall not be less than that prescribed in the Ministerial Regulation, provided that it shall not be less than two million Baht.
In the case where the business of the foreigner under paragraph one is the business requiring permission as specified in the Lists annexed hereto, the minimum capital as prescribed in the Ministerial Regulation for each business shall not be less than three million Baht.
The Ministerial Regulation issued under the provisions of this section may also prescribe the time within which the minimum capital must be brought or remitted into Thailand.
The provisions of this section shall not apply to the case where the foreigner uses money or property derived as revenues from the original business already in operation in Thailand for commencement of another business or for subscribing to shares or investing in any other undertaking or in any other juristic person.[...]"(Foreign Business Act, B.E. 2542 (1999))
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"Article 1 Under Section 14, Paragraph 1, a foreign legal entity must have a minimum capital of THB 2 million to operate a business in Thailand.
Article 2 Under Section 14, Paragraph 2, the required minimum capital for foreign legal entities is 25% of the average annual estimated expenses for three years of operation. This amount must be no less than THB 3 million.
2.1   If the length of business operation is less than 3 years, the foreign legal entity will calculate average estimated expenses for the duration of business operations. The amount must be no less than THB 3 million.
2.2   Under Paragraph 1, the term “estimated expenses” designates the amount of money that the foreign legal entity will use in Thailand in order to acquire assets and to conduct business per annum. 
Article 3 Foreign legal entities not registered in Thailand must bring in or remit the minimum capital to operate a business in Thailand within 3 years from the date business commenced (Section 14, Paragraph 1), or 3 years from the date that permission was granted to conduct business (Section 14, Paragraph 2). At least 25% of the minimum capital must be brought in within three months, at least 50% of the minimum within one year, and thereafter at least 25% of the minimum capital per year. 
3.1   If the length of the foreign legal entity’s business operations is less than 3 years, the minimum capital must be brought in or remitted within 6 months from the date business commenced (Section 14, Paragraph 1), or 6 months from the date that permission was granted to conduct business (Section 14, Paragraph 2). 
Article 4 Foreign-owned businesses in Thailand that are established under privileges granted by treaties and trade agreements must bring in or remit the required minimum capital to Thailand by no later than August 29, 2029. 
Article 5 Foreign legal entities are required to submit proof of minimum capital remittance to the Department of Business Development within 15 days of it being brought into or remitted to Thailand.
Article 6 Foreign-owned businesses that are established under privileges granted by treaties and trade agreements, and are established before the date this regulation takes effect, are also required to bring in or remit the required minimum capital to Thailand by no later than August 29, 2029." (Minimum Capital and the Period to Bring or Remit the Minimum Capital to Thailand B.E. 2562 (2019) [unofficial translation])
Foreign Business Act, B.E. 2542 (1999)
Minimum Capital and the Period to Bring or Remit the Minimum Capital to Thailand B.E. 2562 (2019) [unofficial translation]
[<a href="https://investmentpolicy.unctad.org/investment-laws/laws/40/thailand-foreign-business-act">Act</a>],[<a href="https://resolution.soc.go.th/PDF_UPLOAD/2562/9933255821.pdf">Reg</a>],[<a href="https://mahanakornpartners.com/updated-minimum-capital-requirements-for-foreign-companies-in-thailand/">Other</a>]