US Treaty of Amity Certification in Thailand

Under the 1966 Treaty of Amity and Economic Relations, US nationals and US-majority companies may receive national treatment in Thailand for most business activities. Certification runs through the US Commercial Service and then the Department of Business Development. Sectors reserved by the treaty itself remain closed.

Governing authority / legal basis: Treaty of Amity and Economic Relations between the Kingdom of Thailand and the United States of America (1966); Foreign Business Act B.E. 2542 (1999) for the Thai certificate issued on the strength of the treaty
Turnaround: The US-side certification and the Thai-side certificate are sequential, and each has its own appointment queue. Allow several weeks end to end, driven mainly by how quickly certified US corporate documents can be obtained and legalised.
Fees: Quoted per matter once we see the shareholding, the activity and the documents already on file. Government and registrar fees are charged at the authority's own rate and are separate. Confirm scope and fees with our staff by phone, Line or Email before any filing is prepared.

What we handle

Ownership eligibility review

Tracing the shareholding to US nationals or US-incorporated entities, including intermediate holding companies, before anything is filed.

Sector check

Confirming the intended activity is not within the sectors the treaty itself reserves — communications, transport, fiduciary functions, banking involving depository functions, land and natural resources, and domestic trade in agricultural products are the recognised reservations.

US document package

Certificates of incorporation, good standing, shareholder registers and passports, notarised and certified as the US Commercial Service requires.

Thai certificate filing

The Foreign Business Certificate application to the Department of Business Development once the US-side certification is in hand, with certified Thai translations.

Documents required

Document	Issued / prepared by	Watch out for
Proof of US nationality of the shareholders	Client	Passports for individuals; certificate of incorporation for US entities, plus the chain up to the ultimate US owner.
Shareholder register	Company	Showing US majority. Where a holding company sits in between, each layer must be documented.
Certificate of good standing	US state registry	Recent, and certified as the reviewing office requires.
Thai company documents	Client	Affidavit, memorandum of association and shareholder list where the Thai company already exists.
Description of the intended activity	Client	Checked against the treaty's reserved sectors before the appointment is booked.

Document lists, official fees and acceptance conditions vary between offices, branches and provinces, and change by notification. Confirm with the receiving authority before you act on this page.

How the process runs

1
Eligibility opinion
We confirm the US ownership majority and that the activity is outside the treaty's reserved sectors.
2
US-side certification
The corporate document package is assembled and submitted for certification through the US Commercial Service in Bangkok.
3
Thai-side certificate
With the certification in hand, the Foreign Business Certificate application is filed with the Department of Business Development.
4
Record maintenance
US majority must be maintained. Where shares later move, we flag the filing consequence before the transfer, not after.

Why files get rejected

The treaty benefits US persons and US-majority companies only. A US-resident non-citizen, or a company merely incorporated in the US but foreign-majority owned, does not qualify on that basis alone.
Treaty certification does not remove sector-specific licensing. A regulated activity still needs its own regulator's licence.
If US majority is lost, the basis for the certificate is lost with it. Plan share transfers with that in mind.
Land ownership is not conferred by the treaty. Restrictions under the Land Code continue to apply.
Requirements and appointment procedures of the certifying offices change. We confirm the current checklist before each filing rather than relying on a previous file.

Frequently asked questions

คำถามที่พบบ่อย (FAQ)

Does the Treaty of Amity allow 100 percent US ownership?+

For activities outside the treaty's reserved sectors, yes — a certified company receives national treatment, which in practice allows majority or full US ownership. The reserved sectors named in the treaty remain closed regardless of certification.

Is Amity certification faster than a Foreign Business Licence?+

It is a different track rather than simply a faster one. Certification depends on documented US ownership, which many applicants can prove quickly, whereas a licence turns on a discretionary review. Where both are available, we compare them on document burden and on how the company expects to change hands later.

Can a company with a US parent and a Thai minority shareholder qualify?+

Yes, provided US persons or US entities hold the majority and the ownership chain is documented at every layer. The chain, not the top-line percentage, is what the reviewers examine.

Does certification cover future activities?+

The certificate is granted on the activity described. Adding a materially different activity later, particularly one in a restricted or reserved area, needs to be re-examined before it starts.

Do we still register the company with the DBD?+

Yes. Treaty certification sits on top of ordinary company registration and does not replace it, nor does it replace tax registration or any sector licence.

Authoritative Sources

References & Citations

Official government, legal, and international sources cited throughout this page.

1
th.usembassy.gov· แหล่งทางการ
U.S. Embassy Bangkok — Business services ↗
th.usembassy.gov
2
Department of Business Development· แหล่งทางการ
Department of Business Development, Ministry of Commerce ↗
www.dbd.go.th
3
boi.go.th· แหล่งทางการ
Thailand Board of Investment ↗
www.boi.go.th

ลิงก์ภายนอกเปิดแท็บใหม่ · ใช้ rel="noopener" เพื่อความปลอดภัย · เนื้อหาในแหล่งอ้างอิงเป็นทรัพย์สินของเจ้าของลิขสิทธิ์

General information, not legal advice on your specific matter. We are not a bank, not an insurance broker and not an agent of any state authority, and we do not guarantee any authority's decision.

Talk to us before you file — reply within 24 hours

Tell us your nationality, visa category and the deadline. Our staff confirms the scope and the fee by phone, Line or Email before any work begins.

Chat on Line Call 094-8958999 Email contact@thainotary.co.th

Explore More

Deep Context and Service Standards

Sourced from the Lawyer Act B.E. 2528 (1985), the Lawyers Council Regulation on Notarial Services Attorneys B.E. 2546 (2003), the Personal Data Protection Act B.E. 2562 (2019), the Hague Apostille Convention of 1961, and official publications of the Department of Consular Affairs (MFA).

Firm Overview and Practice Framework

Thai Notary Service is a full-service Thai law office providing document notarization, certified translation, legalization chain management, and international document consultancy. Our team includes Notarial Services Attorneys licensed by the Lawyers Council of Thailand under the Royal Patronage, and we operate offices in Bangkok, Greater Bangkok, and a partner network in every province across Thailand. We serve individuals, expatriates, cross-border couples, students, corporates, multinationals, and government agencies requiring documents with legal effect both inside Thailand and abroad.

All notarial acts follow the Lawyer Act B.E. 2528 (1985) Section 27 read with the Lawyers Council Regulation on Notarial Services Attorneys B.E. 2546 (2003), the sole legal basis authorizing Thai attorneys to certify documents comparable to a foreign Notary Public. Every attorney on our team has completed the accredited training and examination administered by the Lawyers Council and holds a verifiable registration number searchable on the Lawyers Council public registry.

By choosing a firm that houses Notarial Services Attorneys in-house, clients consolidate a multi-stage legalization chain under one accountable roof: attorney notarization, followed by Ministry of Foreign Affairs (MFA) legalization at the Department of Consular Affairs, followed by embassy or consular legalization for the destination country. Since 21 November 2024 the Kingdom of Thailand has become a party to the Hague Apostille Convention (Convention of 5 October 1961 Abolishing the Requirement of Legalisation for Foreign Public Documents). Documents apostilled in Thailand are now accepted in more than 125 member states without embassy re-legalization, materially reducing turnaround time and cost.

General Information and Firm Framework — Deep Context

The firm operates under an ISO 9001:2015 quality-management framework and enforces data protection consistent with the Personal Data Protection Act B.E. 2562 (2019). All client documents are stored with AES-256 encryption at rest and in transit and are retained for ten years in accordance with lawyer-record obligations under the Lawyer Act.

Our team combines Notarial Services Attorneys, NAATI-certified translators, and legal specialists in intellectual property, taxation, cross-border family law, corporate law, and immigration law, together with a support team dedicated to documentation, translation, and government-agency liaison.

Fees are transparent and disclosed both on the website and in the pre-engagement quote, separating professional fees, government fees, travel disbursements (if any), and other line items. The firm issues VAT invoices and official receipts and accepts payment by bank transfer, credit card, PromptPay, and cash.

Trust Standards — PDPA, SLA, Quality Assurance

On data protection, the firm strictly follows the Personal Data Protection Act B.E. 2562 (2019), Sections 24, 26, and 27 — collecting, using, and disclosing personal data only to the extent necessary for the engagement, disclosing purposes, and obtaining consent from data subjects in advance. Clients retain the right to inspect, obtain a copy, rectify, erase, or withdraw consent at any time through the firm's Data Protection Officer (DPO). For clients in the European Union, processing follows GDPR Article 6 (lawful basis) and Article 46 (Standard Contractual Clauses).

Our Service Level Agreement targets an inquiry response within one hour during business hours (09:00–18:00, Monday to Saturday), attorney appointments within twenty-four hours, standard notarization within one business day (or two to three hours on express service), certified translation within three to five business days per ten A4 pages, MFA legalization within two business days on standard service (one business day express), and embassy legalization typically within three to fifteen business days depending on the mission's own policy.

Every deliverable passes a three-tier quality-assurance chain: (1) the responsible attorney or translator, (2) a Senior Attorney or department head reviewing substance and formatting, (3) a Quality Control desk performing the final pre-delivery check. Any firm-side error is remedied at no additional cost, and if a document is rejected by a government authority due to a firm-side error, we cover the entire re-filing fee.

Contact and Initial Consultation

Initial consultation is complimentary via Line @thainotary or by phone at 094-8958999. The team responds within one hour during business hours. Every inquiry is treated confidentially under the Lawyers Council ethics rules and the Personal Data Protection Act.

Treaty of Amity certification for US-owned companies