The full name is the Treaty of Amity and Economic Relations between the Kingdom of Thailand and the United States of America. It was signed in Bangkok on 29 May 1966, and Thai official documents date it B.E. 2511, the year it took effect.
For most foreign-owned companies, the Foreign Business Act decides early on whether a business can go ahead at all. A qualifying American company is largely exempt from those rules.
What is the US-Thai Treaty of Amity?
A treaty under which each country treats the other's companies, for most business, the way it treats its own.
Article IV is the part that matters for business. Each country lets nationals and companies of the other establish and acquire interests in enterprises of all types for commercial, industrial, financial and other business, and an enterprise owned or controlled by them may conduct its activities on terms no less favourable than an enterprise owned by the host country's own nationals [Treaty of Amity, Article IV paragraphs 1 and 4].
The Foreign Business Act gives that effect in Thailand. A foreigner operating a listed business by virtue of a treaty is exempt from the Act's licensing rules and is governed by the treaty instead [Foreign Business Act B.E. 2542, section 10].
What does the Treaty let an American-owned company do?
Run businesses that the Foreign Business Act otherwise closes to foreign-owned companies, or opens only with permission, by obtaining a certificate. The reserved areas are the exception.
Without the Treaty, a foreign-owned company that wants to run a business on List Three needs permission from the Director-General of the Department of Business Development, given with the approval of the Foreign Business Commission [section 8(3)]. A List Two business needs the Minister's permission with Cabinet approval [section 8(2)]. A qualifying American company is exempt from those provisions [section 10].
The Department's own advisory rulings put it the same way: an American company protected by the Treaty may carry on the businesses on the lists, except the ones Thailand reserved [Department of Business Development advisory ruling, January 2020].
Who qualifies as an Amity company?
A Thai company in which Americans hold the majority and Americans or Thais make up most of the board. The rest of the shares can be held by anyone.
The Department of Business Development has set out the qualifications [Department of Business Development advisory ruling, October 2011]:
- The company is formed under Thai or US law.
- Americans hold more than half of the capital and are more than half of the shareholders or partners.
- More than half of the directors are American or Thai, or both.
- A director who signs for the company alone is not a national of a third country.
- Where several directors sign together, most of them are not nationals of a third country.
Only the majority has to be American. The rest of the shares can be held by Thai partners or by shareholders of any other nationality, so an Amity company can be wholly foreign-owned. It is still a Thai limited company, registered with the Department of Business Development and taxed as a company incorporated under Thai law [Revenue Department, corporate income tax guide].
In practice the Department relies on a certification letter from the US Commercial Service at the US Embassy in Bangkok as proof that the company is American-owned. The Embassy runs its own check before issuing that letter, and it looks through any American parent company to who ultimately owns it.
Which businesses does the Treaty leave out?
Six reserved areas, and the professions.
Article IV(2) of the Treaty lets each country restrict foreign interests in enterprises engaged in communications, transport, fiduciary functions, banking involving the taking of deposits, the exploitation of land or other natural resources, and domestic trade in indigenous agricultural products [Treaty of Amity, Article IV paragraph 2]. The Department of Business Development applies them: a company cannot claim the Treaty's protection for those six areas [Department of Business Development advisory ruling, October 2011].
The practice of professions sits outside the Treaty's business provisions altogether [Treaty of Amity, Article IV paragraph 3].
Can an Amity company own land, or lease and rent out a house?
It can lease land and rent out a house. It cannot own land.
The Land Code gives a company with more than forty-nine percent foreign shareholding the same rights in land as a foreigner [Land Code B.E. 2497, section 97]. A foreigner may acquire land only by virtue of a treaty that gives the right to own immovable property, and then only with the Minister's permission [Land Code, section 86]. In practice the Land Office does not treat the Treaty of Amity as such a treaty, and an Amity company does not own land.
Leasing is different. In our experience the Department of Business Development reads "exploitation of land" as mining and similar use of natural resources, and an Amity company may lease land and rent out a house.
Can an Amity company run a hotel or villa rentals?
Yes. An Amity company can hold the hotel licence and run the hotel itself.
Hotel business is on List Three of the Foreign Business Act, the list a foreign-owned company normally needs permission for [Foreign Business Act, List Three (17)]. An Amity company is exempt from that requirement [section 10], and hotels are not among the six reserved areas, so it can operate as a hotel company. It applies for the hotel licence like any operator, because no person may operate a hotel business without one [Hotel Act B.E. 2547, section 15]. The Hotel Act sets no nationality test for the applicant, though the company's representative must be domiciled or resident in Thailand [Hotel Act, section 16]. How villa rentals fall under the Hotel Act, and when they need a licence at all, is set out in renting out a Thai villa: when a hotel licence is required.
How does a company get the Amity certificate, and how long does it take?
Register the company, get the US Embassy's certification, and file it with the Department of Business Development, which must issue the certificate within thirty days.
- Register a Thai limited company at the Department of Business Development, with Americans holding the majority of the shares and more than half of the directors American or Thai.
- Take the company documents to the US Commercial Service at the US Embassy in Bangkok for its certification letter.
- File that letter with the Department of Business Development on form ต.6 (Tor Or 6). The fees are 2,000 baht for the application and 20,000 baht for the certificate [Department of Business Development guidance on the Foreign Business Act].
- The Department reviews the filing and approves it. The Director-General must issue the certificate without delay and no later than thirty days from receiving the notification, or say within the same thirty days why not [Foreign Business Act, section 11]. The certificate states any conditions set by the government or the Treaty.
- Once the certificate is issued, the company is certified and can start operating.
The minimum capital is set two ways. The Act requires a foreigner to bring in at least the minimum set by Ministerial Regulation, and never less than two million baht [Foreign Business Act, section 14]. For treaty certificates the Department's guidance sets the minimum at 25 per cent of the company's average yearly expenses projected over three years. On average projected spending of 100 million baht a year, that is 25 million baht [Department of Business Development guidance on the Foreign Business Act].
Amity certificate, Foreign Business Licence or BOI: which one?
Three routes into a business on the Foreign Business Act's lists, each with its own test.
| Route | Who can use it | How it is granted | Main limits |
|---|---|---|---|
| Treaty of Amity certificate | A company owned and run by Americans. | Notification, with the certificate due within thirty days [s.11]. | The six reserved areas and the professions [Treaty, Article IV]. |
| Foreign Business Licence | Any foreign-owned company. | Permission from the Director-General with the Commission's approval for List Three [s.8(3)]. | Discretionary, weighing the factors in s.5. |
| BOI promotion | A business promoted by the Board of Investment. | A certificate within thirty days of showing the promotion [s.12]. | Limited to the promoted business. |
Section numbers are the Foreign Business Act B.E. 2542 unless the Treaty is named.
What this means in practice
In our experience the Treaty is the most direct route for an American investor into a business that would otherwise need a Foreign Business Licence. Most of the effort goes into qualifying cleanly. American ownership has to hold up through every company above the Thai one, and the directors and signing powers have to meet the test from the day the company is registered. The capital has to be in place, and the activity has to sit outside the six reserved areas.
Land stays a separate question from the business. A company that will lease property for its business can do so, and a plan that depends on owning land needs a different structure.
How we set up an Amity company, step by step, is on our US Treaty of Amity companies page.
Book a consultation →Sources Show all 13 sourcesHide sources
Every statement in this article rests on one of the 13 sources below, each named by instrument and article or section so it can be checked against the text itself.
- Treaty of Amity and Economic Relations between the Kingdom of Thailand and the United States of America, signed at Bangkok on 29 May 1966 (United Nations Treaty Series, No. 9345), Article IV paragraphs 1 to 4. National treatment for establishing and acquiring interests in enterprises; the reserved areas (communications, transport, fiduciary functions, banking involving depository functions, the exploitation of land or other natural resources, domestic trade in indigenous agricultural products); professions excluded; enterprises owned or controlled by nationals of the other Party permitted to conduct their activities on terms no less favourable.
- Foreign Business Act B.E. 2542, sections 5 and 8. The factors weighed in granting permission; List Two and List Three businesses need permission.
- Foreign Business Act B.E. 2542, sections 10 and 11. Exemption for foreigners operating under a treaty; notification to the Director-General and issue of the certificate within thirty days, stating the conditions.
- Foreign Business Act B.E. 2542, section 12. Certificate for a business promoted under the investment promotion law.
- Foreign Business Act B.E. 2542, section 14. Minimum capital not less than that prescribed by Ministerial Regulation and not less than two million baht.
- Department of Business Development, guidance on the Foreign Business Act. Form ต.6; fees of 2,000 and 20,000 baht; minimum capital for treaty certificate holders of 25 per cent of average annual projected expenses over three years.
- Department of Business Development, advisory ruling, October 2011 (B.E. 2554). Qualifications for Treaty protection and the reserved businesses.
- Department of Business Development, advisory ruling, January 2020 (B.E. 2563). An American company protected by the Treaty may carry on the listed businesses except the reserved ones.
- Land Code B.E. 2497, sections 86 and 97. Acquisition of land by a foreigner only by virtue of a treaty giving the right to own immovable property, with the Minister's permission; companies with more than forty-nine percent foreign shareholding have rights in land as foreigners.
- Hotel Act B.E. 2547, section 15. No hotel business without a licence from the Registrar.
- Foreign Business Act B.E. 2542, List Three (17). Hotel business, except hotel management services, is a List Three business.
- Hotel Act B.E. 2547, section 16. Qualifications of a licence applicant; for a juristic person, the representative must meet them, including domicile or residence in Thailand.
- Revenue Department, corporate income tax guide. A limited company incorporated under Thai law is a corporate income tax payer.
Section and article numbers are given so you can check every statement in this article against the text itself. Where a provision exists only in Thai, the section number and the name of the Act are stated so the Thai text can be located.
Is the Treaty of Amity still in force?
Thailand still applies it. The Foreign Business Act exempts businesses operated under a treaty, and the Department of Business Development applies the Treaty of Amity in its published advisory rulings, including rulings from 2019 and 2020.
Who counts as an American company under the Treaty?
A company formed under Thai or US law in which Americans hold more than half of the capital and are more than half of the shareholders, with more than half of the directors American or Thai. A director who signs alone, or most of those who sign together, must not be a national of a third country.
Can an Amity company own land in Thailand?
No. A company with more than forty-nine percent foreign shareholding has the same rights in land as a foreigner, and in practice the Treaty of Amity is not treated as a treaty giving the right to own land. An Amity company can lease land.
Can an Amity company be 100% foreign-owned?
Yes. Americans must hold more than half of the capital, and the rest can be held by Thai partners or by shareholders of any other nationality.
Can an Amity company get a hotel licence?
Yes. Hotel business is not among the reserved areas, so an Amity company can hold the hotel licence and run the hotel, subject to the Hotel Act's requirements like any other operator.
How long does the Amity certificate take?
The Foreign Business Act requires the Director-General to issue it within thirty days of receiving a complete notification. Registering the company and obtaining the US Commercial Service letter come first and take their own time.
What is the minimum capital for an Amity company?
Not less than two million baht under the Foreign Business Act. For treaty certificates the Department of Business Development's guidance sets the minimum at 25 per cent of the company's average yearly expenses projected over three years.
Which businesses can an Amity company not do?
Communications, transport, fiduciary functions, banking involving the taking of deposits, the exploitation of land or other natural resources, and domestic trade in indigenous agricultural products. The practice of professions is also outside the Treaty.
This article is general information about Thai law, not legal advice, and reading it does not create a lawyer-client relationship. It reflects the legislation as reviewed on 24 October 2026. Thai law and administrative practice change, and practice varies between offices and provinces. For advice on a particular situation, get in touch. See our editorial standards and disclaimer.
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