The Treaty of Amity: Why US Citizens Can Own 100% of a Business in Thailand

What the Treaty of Amity actually is

The US-Thailand Treaty of Amity and Economic Relations was signed in 1966 and came into force in 1968. Its core principle is national treatment — meaning American citizens and US-majority-owned companies are treated the same as Thai businesses in most commercial sectors.

In practice, this means US citizens can own up to 100% of a Thai company without needing a Thai partner, without applying for a Foreign Business License in most cases, and without the ownership restrictions that apply to every other foreign nationality.

It is one of the most valuable bilateral agreements for American investors in Thailand — and most people planning retirement there have never heard of it.

What the Treaty covers

The treaty applies to most standard commercial activities, including consulting and professional services, technology and software development, trading and e-commerce, some hospitality and service businesses — though licensing, sector restrictions, lease terms and work permits still need separate legal review, education and training, and marketing and advertising services.

For US retirees thinking about a second act — whether that is a café, a consulting practice, a digital business or a small agency — the treaty removes the ownership structure problem that trips up every other foreign national.

What the Treaty does not cover

The treaty is not a blanket exemption from Thai law. There are sectors it cannot help with.

US citizens cannot own land in Thailand — this applies to all foreign nationals regardless of the treaty. Long-term leases, superficies rights or condo ownership within the 49% foreign quota are the alternatives.

The treaty also does not cover domestic trade in indigenous agricultural products, communications and transport, banking and finance, and the extraction of natural resources.

Standard Thai corporate taxes apply in full — the treaty provides no tax advantages. Corporate income tax is 20%, VAT is 7%. If you want tax incentives, that requires a separate BOI application.

Work permits and visas are not affected by the treaty either. To legally work in your own Thai company, you still need a Non-Immigrant B visa and a work permit. The treaty gives you ownership rights — not immigration rights.

How to actually set up a Treaty of Amity company

The process is more structured than most people expect, but it is manageable.

First, register a Thai limited company with the Department of Business Development. The company must be majority US-owned from the start — at least 51% of shares held by American citizens or a US-majority company. At least 50% of directors must be American or Thai nationals.

Second, apply for Treaty of Amity certification from the US Commercial Service at the US Embassy in Bangkok. This requires company registration documents, shareholder passport copies, proof of US citizenship, and a business plan describing your intended activities. The Embassy fee is approximately USD $365.

Third, submit the Embassy certification to the Thai Department of Business Development to register your company as a Treaty of Amity company and receive a Foreign Business Certificate.

The full process typically takes 6 to 12 weeks. Minimum registered capital is THB 2 million for businesses not restricted under the FBA, and THB 3 million for those that are. Each foreign work permit requires THB 2 million in registered capital and four full-time Thai employees per foreign employee.

Get legal advice before you start. The documentation requirements are precise and errors cause delays.

Treaty of Amity vs BOI — which route is right for you?

These are not mutually exclusive. They serve different purposes.

The Treaty of Amity solves the ownership problem. It lets you own 100% of your company without a Thai partner in most sectors. It does not provide tax incentives.

BOI promotion solves the tax problem. It can provide corporate tax holidays of up to 8 years for qualifying businesses in promoted sectors including software, digital services and advanced technology. BOI may also allow 100% foreign ownership in promoted sectors — so for some businesses, BOI alone may be sufficient.

For a US citizen building a digital or tech business in Thailand, the strongest structure may combine both: Treaty of Amity for clean 100% ownership and operational flexibility, with a BOI application layered on top for tax incentives.

What this means for US retirees specifically

If you are a US citizen over 50 thinking about Thailand not just as a place to retire but as a place to build something, the Treaty of Amity changes the calculation significantly.

British nationals, European nationals and most other foreign retirees normally need a genuine Thai-majority structure, a Foreign Business License, BOI promotion, or another lawful route. Nominee arrangements used to bypass foreign ownership restrictions are risky and should not be treated as a legal solution.

You do not. Your ownership can be clean, simple and fully legal from day one.

That does not mean it is easy. You still need the right visa, a work permit, registered capital, Thai employees and ongoing compliance. But the foundational ownership problem that stops most foreigners — you have already solved it by holding a US passport.

Frequently asked questions

The honest bottom line

The Treaty of Amity is a genuine legal advantage that most US citizens planning retirement in Thailand do not know they have.

It does not make running a business in Thailand simple. Thai taxes, visa rules, work permits, employee ratios and capital requirements all still apply. But it removes the ownership problem — the one that forces every other foreign national into a Thai-majority structure or a complex workaround.

If you are a US citizen over 50 and you want to build something in Thailand, understanding this treaty is the right starting point.