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Authentication and Legalization Service for Thailand

Updated: Mar 22, 2023

What is Authentication or Legalization?

Making a document issued in one country valid for legal purposes in other countries is called authentication and legalization. Authentication proves that the signature and the seal on the document are genuine and it makes the document effective, valid, and recognized in another country.

The documents issued in the U.S. and intended for use in these non-Hague Apostille countries will be required to complete the authentication process, which may involve multiple steps and several government agencies.

If the country of use is a Hague Apostille country, only Apostille is needed, a much more simplified process of authentication. The countries that joined the Hague Apostille Convention reached an agreement on abolishing the requirement of legalization for Foreign Public Documents.

This is why you may have heard that some documents require Apostille, but others need Authentication or Legalization. It all depends on whether the country of use has joined the HAGUE CONVENTION OF 5 OCTOBER 1961.

How to authenticate and legalize documents issued in the U.S. for use in Thailand?

Thailand is not a member of the Hague Apostille Convention. Any documents issued in the U.S. destined for use in Thailand require authentication by the Secretary of State, the U.S. Department of State, and the Embassy/Consulate of Thailand in the U.S. The specific government agencies involved in the authentication vary by document type.

No matter whether it's a document notarized by a local notary, a local and state document issued by the court or official department, or it's a federally-issued document, they all can be authenticated.

👉 For notarized or local and state documents:

  1. Secretary of State Authentication

  2. the U.S. Department of State Authentication

  3. the Embassy of Thailand Authentication

Tips: Documents issued in these 7 states need additional authentication before being presented to the Secretary of State's office.

👉 For federally-issued documents:

  1. the U.S. Department of State Authentication

  2. the Embassy of Thailand Authentication

The Consular Jurisdictions of the Embassy/Consulates of Thailand in the U.S.

Thailand has one embassy and three consulates in the United States.

The Royal Thai Embassy, Washington D.C.

Jurisdictions: 1. Alabama 2. Delaware 3. Florida 4. Georgia 5. Louisiana 6. Maryland 7. Mississippi 7. Mississippi 9. South Carolina 10. Tennessee 11. Texas 12. Virginia 13. West Virginia 14. Puerto Rico 15. District of Columbia

The Royal Thai Consulate-General, Los Angeles

Jurisdictions: 1. Alaska 2. Arizona 3. California 4. Colorado 5. Idaho 6. Montana 7. New Mexico 8. Nevada 9. Oregon 10. Utah 11. Washington 12. Wyoming 13. Hawaii and U.S. Pacific Territories

The Royal Thai Consulate-General, Chicago

Jurisdictions: 1. Arkansas 2. Illinois 3. Indiana 4. Iowa 5. Kansas 6. Kentucky 7. Michigan 8. Minnesota 9. Missouri 10. Nebraska 11. North Dakota 12. Oklahoma 13. South Dakota 14. Wisconsin

The Royal Thai Consulate-General, New York

Jurisdictions: 1. Maine 2. Massachusetts 3. New Jersey 4. New York 5. Pennsylvania 6. Rhode Island 7. Connecticut 8. Vermont 9. New Hampshire 10. Ohio

Documents we authenticate

These documents may include :

(This list is not all-inclusive. Please contact us if your document is not listed below.)

  • Birth Certificate

  • Death Certificate

  • Marriage Certificate

  • Divorce Certificate

  • Court Document

  • FBI – Background check

  • Background check of the local police department

  • U.S. Residence Certificate/Affidavit

  • Name Change Certificate/Petition for Name Change

  • Driver's License

  • Certificate of Naturalization

  • Any Translated Document

  • IRS Form-6166

  • Single Status Affidavit

  • Affidavit of One and The Same

  • Gift Affidavit

  • Waiver of Inheritance

  • Power of Attorney of Real Estate Transaction

  • Power of Attorney of Divorce Proceedings

  • Other Powers of Attorney

  • Proof of Income

  • Employment Verification Letter

  • Bank Statement

  • Diploma

  • Transcript

  • Health Certificate/Medical Letter

  • Home Study

  • Child Adoption Documents

  • Articles of Incorporation/Articles of Organization

  • Amendment

  • Company's Annual report (Statement of information)

  • Bylaws (Operating Agreements)

  • Good Standing Certificate

  • Business License

  • Meeting Minutes

  • Board Resolutions

  • Shareholders' Resolutions

  • Corporate Stock Ledger

  • Financial documents

  • Bank documents

  • Tax documents

  • Contracts

Besides Thailand, we also authenticate documents destined for use in other non-Hague Apostille countries. The authentication process can be complicated, time-consuming, and distracting that requires expertise and experience. So just leave it to us! Our experts can provide you with a full range of fast services that allow you to save time and focus on your own careers and key areas.


American Notary Service Center Inc. provides fair, fast, confidential, and professional document notarization and certification services for our clients. We also provide various assistance services to small businesses led by socially and economically disadvantaged groups. Our service helps small businesses obtain federal government contracts, gain a foothold in the market, and boost their sales. For more information, please visit our website at, and contact us by calling 202-599-0777 or by email at


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