Treaty of Amity in Thailand: How Americans Own 100% of a Thai Company (2026)

Last updated on August 16, 2026

Updated 12 August 2026. The US-Thailand Treaty of Amity and Economic Relations is the single biggest advantage an American investor has in Thailand. Signed on 29 May 1966 and in force since 1968, it lets US citizens and US-majority-owned companies own up to 100% of a Thai company and be treated, for most business purposes, as if they were Thai. Four separate DBD rule changes landed between January and August 2026, and every one of them makes the ordinary 49/51 structure harder to build. This guide covers what the treaty gives you, who does not qualify, how registration works now, and what quietly voids your certificate later.

The Treaty route is one of several structures compared in our guide to business setup in Thailand.

What changed in 2026, and why it matters to Americans

On 1 August 2026 the Department of Business Development brought Central Partnership and Company Registrar Order No. 2/2569 into force. If a foreign national holds under 50% of a Thai company, or holds no shares but signs as an authorised director, the registrar now wants three things it did not ask for before: three months of bank statements from each Thai shareholder covering the period before they paid for their shares, bank statements from the director’s account that received the money, and a prescribed Investment Explanation Letter tracing every transfer. Statements that do not line up with the declared subscription get the filing rejected.

That order sits on top of three earlier moves in the same year. Order No. 2/2568 started the bank-statement requirement on 1 January. On 1 April the DBD added in-person verification for amendments involving foreign participation. On 1 July it closed the walk-in counter for new private limited company incorporations and pushed them all through DBD Biz Regist. The DBD has prosecuted 852 companies, put THB 15.1 billion of economic damage on the record, and estimates that roughly 94,000 Thai companies carry nominee shareholders.

Every one of those measures targets the 49/51 structure. An Amity company does not use one. You hold 100% of the shares in your own name, so the Thai shareholder requirement disappears and so does the paperwork trail the DBD built to test it. Nobody at the Ministry of Commerce has to satisfy themselves that your Thai partner funded their shares, because you have no Thai partner.

What the treaty actually gives you

Under the Foreign Business Act B.E. 2542 (1999), a company is foreign if 50% or more of its shares are held by non-Thais, and foreign majority ownership of most service and trading businesses is restricted. The Treaty of Amity overrides that for Americans. A qualifying US company receives national treatment: it may be up to 100% American-owned and may operate in most sectors without a Foreign Business Licence.

Sections 10 and 11 of the Act carve out the treaty route. A foreigner operating under a treaty to which Thailand is a party notifies the Director-General under the prescribed ministerial regulation and receives a Foreign Business Certificate. Section 11 gives the Director-General 30 days from the date of the written notification to issue it.

The word “certificate” carries more weight than most guides admit. A Foreign Business Licence under section 17 is a discretionary approval: a committee weighs your application, considers whether Thai nationals are ready to compete in your sector, and can say no. A certificate under section 11 records a right the treaty already conferred. The registrar checks that you qualify, then issues.

Clients get ahead of themselves here. The treaty covers ownership of a business. It does not touch land, work permits, visas, or tax. Your corporate tax bill matches a Thai company’s. Anyone selling Amity as a shortcut past all four is selling you something the treaty never contained.

Who qualifies, and who thinks they qualify but does not

The 51% rule and the ownership chain

US citizens or US-incorporated entities must hold at least 51% of the shares, and US persons must hold a majority of the directorships. A company owned through a chain of other companies can still qualify, but every layer has to trace back to US citizens or US-incorporated entities. A Delaware corporation that is 60% owned by a Japanese group fails, even though the immediate shareholder of the Thai company is unmistakably American on paper.

The majority-directors rule

You can appoint directors from other countries, but plan the signing authority around them. Many firms require a US director to co-sign wherever a third-country director signs, so that operational control stays where the treaty needs it. Our note on appointing and removing directors covers the mechanics.

The preferred-share voting trap

Counting share certificates is not enough. If preferred shares carry weighted voting rights that hand effective control to non-American holders, the arithmetic that satisfied you fails the substance test. Check voting rights per share class before you file, not after the registrar queries it.

Citizens, green-card holders, LLCs and corporations

The treaty runs to US citizens and to entities incorporated in the United States. A green-card holder who has not naturalised is not a US national for treaty purposes, whatever their tax filing says. Both corporations and LLCs formed in a US state qualify, though LLCs draw closer scrutiny of the membership register because ownership sits in an operating agreement rather than share certificates. Bring the operating agreement and the full membership list.

What the treaty does not cover: the Big Six

The treaty is broad but not unlimited. Six categories are excluded, and an American company gets no advantage in them:

1. Communications
2. Inland and domestic transportation
3. Fiduciary functions, which covers managing money or property for someone else
4. Banking involving depository functions
5. The exploitation of land or other natural resources
6. Domestic trade in indigenous agricultural products, though export trade stays open

Most American businesses in Thailand sit outside all six. Consulting, software, marketing, manufacturing, import and export, restaurants and retail all fall inside the treaty. Test your revenue lines against the list before you file, because the registrar reads the objects clause you register, not your pitch deck.

Registering an Amity company step by step in 2026

Registration splits into two legs running on different rails. The Thai leg is online and fast. The US leg is notarised paper moving through the Embassy. Start the paper leg first, because it sets your critical path.

Step 1: Assemble and notarise the US corporate documents

A US individual applying as sole shareholder needs a notarised copy of their passport or birth certificate. A US corporate shareholder needs articles of incorporation, corporate bylaws, a shareholder list showing each holder’s nationality, and notarised copies of the passports of the US shareholders and directors. A notary public in the United States must notarise these, or a consular officer at the US Embassy in Bangkok or the Consulate in Chiang Mai. Americans living in Thailand book that through American Citizen Services.

Step 2: Certification by the US Commercial Service

Submit the notarised set to the Commercial Service at the US Embassy in Bangkok. Prepare four sets: originals in English, English photocopies, Thai translations, and Thai photocopies. The certification letter follows within three to five business days once your file is complete. Most delays here trace back to a missing notarisation or a translation that does not match the original.

Step 3: Incorporate the Thai limited company through DBD Biz Regist

Since 1 July 2026 the DBD accepts new private limited company incorporations only through Biz Regist. Reserve the name, file the memorandum of association, register the company. Promoters and authorised directors still sign certain documents, either wet-ink or electronically through DBD e-Service or ThaID. Non-Thai signatories cannot use ThaID, so budget extra days for couriered signatures. One-day incorporation works for an all-Thai signatory group and not for yours. See registering a company in Thailand for the general process.

Step 4: Apply to the DBD for the Foreign Business Certificate

File the Commercial Service letter and the section 11 notification with the DBD, with THB 2,000 for the government fee. The Director-General has 30 days to issue. Once the certificate lands, your company operates in restricted-list activities with 100% American ownership.

Realistic timeline and cost

Leg	Working time	What drives it
US document preparation and notarisation	1 to 3 weeks	Where your shareholders live and how fast they sign
US Commercial Service certification	3 to 5 business days	Completeness of the file
Thai incorporation via Biz Regist	3 to 10 days	Signature logistics for non-Thai directors
DBD Foreign Business Certificate	Up to 30 days by statute	The section 11 deadline
Total, start to certificate	6 to 10 weeks	Run the US leg in parallel to hit the short end

Government fees stay modest. Our fixed fee to register a Thai company is 45,000 THB, and the Amity certification is quoted on top depending on the ownership chain. See our legal fees page.

Amity, BOI promotion, a Foreign Business Licence, or a 49% Thai company

	Treaty of Amity	BOI promotion	Foreign Business Licence	49% Thai company
Foreign ownership	100%, Americans only	Up to 100%	Up to 100%	49% maximum
Decision type	Certificate, right-based	Discretionary	Discretionary	Registration only
Typical timeline	6 to 10 weeks	3 to 6 months	3 to 6 months	2 to 4 weeks
Sector limits	The Big Six stay closed	Only promoted activities	Case by case	None beyond the FBA
Tax incentives	None	Corporate tax holidays available	None	None
Land ownership	No	Possible for promoted projects	No	Possible, and the DBD is auditing exactly this
2026 nominee exposure	None	None	None	High

Americans often ask whether to use the Treaty of Amity or apply for Board of Investment (BOI) promotion. They are different tools. Amity is the fastest way to 100% American ownership of an ordinary service or trading business, and it gives no tax break. BOI promotion is activity-specific and slower, but it adds corporate tax holidays, easier work permits, and in some cases the right to own land for the promoted project. For a straightforward consulting, trading, or service company, Amity is usually the right call. For manufacturing or a target BOI activity, BOI often wins. Some businesses use both. Our fuller breakdown sits at BOI vs Foreign Business Licence.

Why Amity beats a nominee structure in 2026

Thai law punishes both sides of a nominee arrangement. Under FBA section 36 a Thai national who holds shares on a foreigner’s behalf faces up to three years in prison and a fine between THB 100,000 and THB 1,000,000. Section 37 hits the foreigner who runs a restricted business without the required licence or certificate with the same range. A company that ignores a court order to unwind the structure faces daily fines of THB 10,000 to THB 50,000, and the court can order it dissolved.

Thai courts look past the share register. In the nominee line of Supreme Court decisions the judges asked who funded the company, who controlled it and who took the benefit, then treated the company as foreign in substance and voided the land transaction. Sham loan agreements built to give a foreigner control have been held to be prohibited nominee arrangements.

Your Thai partner carries criminal exposure alongside you. Clients underestimate that, and it is what makes nominee structures fragile the moment a relationship sours. Amity removes the question. Read the enforcement detail at Thai nominee shareholders and the case analysis at nominee crackdowns and court cases.

Capital, work permits and Thai staff

On minimum capital, the ordinary Foreign Business Act figures apply: at least THB 2 million for a business that is not otherwise restricted, and at least THB 3 million for each activity that would need a Foreign Business Licence for a non-American.

Work permits follow separate arithmetic that the treaty does not change. You need THB 2 million of registered and fully paid-up capital per foreign work permit, capped at ten, and four Thai employees for each permit issued. Below THB 3 million paid-up, work permits get difficult whatever your certificate says. Plan capital around the headcount you want. See Non-B business visas for the visa side and corporate tax in Thailand for the tax side.

Your Amity company still cannot own land

This is the hard limit that catches people out. Land ownership by foreigners is barred by Section 86 of the Land Code, and the Treaty of Amity does not change that. An Amity company can own the building on the land, but not the land itself. What works instead:

• A registered lease of up to 30 years, which is the standard commercial solution
• A condominium unit within the 49% foreign quota of the building
• A usufruct or superficies where the structure suits your use of the land

Anyone proposing that your Amity company hold land through Thai shareholders is proposing the exact arrangement the DBD spent 2026 dismantling.

Keeping the certificate: what voids Amity protection

Amity status is not a one-time approval. The certificate reflects a structure and dies with it. Watch four events:

• US shareholding drops below 51%. The certificate becomes void and the FBA restrictions snap back.
• US directors stop holding the board majority. Same result.
• A share transfer moves control to non-Americans, including through the ownership chain above your immediate shareholder.
• A preferred-share reorganisation shifts voting rights to non-American holders while the certificate count still looks compliant.

Before you issue new shares, admit an investor, or restructure a US parent, run the Amity test. Notify the DBD when shareholding or directorship changes materially, and refresh the Embassy certification when your shareholder composition moves. Checking beforehand costs a conversation; discovering it afterwards costs the certificate.

Ongoing compliance calendar

• Within 4 months of fiscal year end: hold the annual general meeting and adopt the audited financial statements. Section 1197 of the Civil and Commercial Code requires the auditor-examined balance sheet to reach a general meeting within four months of its date.
• Within 1 month of the AGM: file the approved financial statements and the meeting minutes with the DBD, electronically through the e-filing system.
• Within 14 days of the AGM: file the updated list of shareholders.
• Monthly and annually: corporate income tax, withholding tax and VAT filings on the ordinary Thai schedule.

How ThaiLawOnline can help

We handle the whole Amity process: forming the Thai company, preparing the ownership evidence, obtaining the US Commercial Service certification, and filing for the Foreign Business Certificate at the DBD. We also advise on the sensible structure where an American holds the business and land needs are met through a lease or usufruct rather than ownership. Our fixed fee to register a Thai company is 45,000 THB; the Amity certification is quoted on top depending on the ownership chain.

One practical warning from experience: the treaty protects genuine American ownership, not an American name on paper over a non-American business. If the real capital and control are not US, the certification will not hold up, and the exposure is the same as any other misrepresentation to the DBD. If you are American, use the treaty properly and it is one of the best deals in Thai corporate law. Contact us to start.

Frequently asked questions

Can an American own 100% of a company in Thailand?

Yes, through the Treaty of Amity, provided the business sits outside the six reserved sectors and you hold the Foreign Business Certificate. No other nationality has this route into Thailand.

Is the Treaty of Amity still in force in 2026?

Yes. The treaty remains in force and the 2026 US tariff round runs on a separate track. Nobody is renegotiating it.

How long does Treaty of Amity registration take?

Six to ten weeks from starting the US document preparation to holding the certificate. The Commercial Service takes three to five business days once your file is complete, and section 11 gives the DBD Director-General 30 days to issue.

How much does it cost?

Government fees are small, with THB 2,000 for the certificate application plus incorporation fees. Our fixed fee to register the Thai company is 45,000 THB, with the Amity certification quoted separately depending on the ownership chain.

Can a Treaty of Amity company own land in Thailand?

No. Section 86 of the Land Code bars it and the treaty does not change that. Use a registered lease of up to 30 years, a condominium unit within the foreign quota, or a usufruct.

Do I still need a work permit?

Yes. Amity covers ownership, not immigration. You need THB 2 million of paid-up capital per work permit and four Thai employees for each one.

What happens if I sell shares to a non-American?

If US ownership falls below 51% or US directors lose the board majority, the Foreign Business Certificate becomes void and the FBA restrictions apply again. Test any transfer before you execute it.

Does a green-card holder qualify?

No. The treaty runs to US nationals. Permanent residence is not nationality for this purpose.

Treaty of Amity or BOI promotion?

BOI wins where you qualify for a tax holiday and can wait three to six months. Amity wins on speed and certainty for service businesses, and it carries no tax incentive at all.

Can an Amity company run e-commerce, consulting or a restaurant?

Yes. All three sit outside the six reserved sectors. Match your registered objects to what you actually sell before filing.

This page describes Thai law as it stood on 12 August 2026. Thai law changes, and how it applies depends on your circumstances. It is general information, not legal advice for your situation.

Jurisdiction: Thailand. Written and reviewed by ThaiLawOnline, a licensed Thai law firm practising since 2006.