Patents of Invention

– Patent Act, in effect since September 12, 1979, amended September 30, 1992 and September 27, 1999.

Membership in International Conventions

– Convention Establishing the World Intellectual Property Organization (WIPO), since December 25, 1989.
– WTO’s TRIPS Agreement, since January 1, 1995.
– Paris Convention for the Protection of Industrial Property, Stockholm Act, since August 2, 2008.
– Patent Cooperation Treaty (PCT), since December 24, 2009.


Applicant: an inventor has the right to apply for a patent and the right can be assigned or transferred by succession. However, the assignment of the right to apply for a patent must be in writing and shall require the signatures of the assignor and assignee. A natural person or a legal entity may be the assignee. Only individuals can be the inventors per se.

Foreigners: a foreign national obtains the same protection as a native person, if the foreigner’s country is a party to an international patent treaty or convention to which Thailand is also a party. Foreigners who do not meet the above criteria may apply for patent protection in Thailand if he/she has a domicile or an ongoing, functioning industrial or commercial enterprise in either Thailand or a country which is a member of an international patent convention or treaty to which Thailand is a party.

Not protectable: microorganisms which naturally exist and their components, animals and plants or extract of same, scientific or mathematical rules or theories, computer programs, methods for diagnosing, treating or curing human or animal diseases, inventions which are contrary to public order or morality, public health or welfare.

Priority: all foreign applicants entitled to national treatment will be able to claim priority rights within twelve months of the first foreign filing date.

Novelty: does not form part of the state of the art which includes: (1) the invention has been widely known or used by others in the Kingdom; (2) any information made available to the public before the filing or priority date; (3) the invention is already patented inside or outside the Kingdom; (4) an invention for which an application for a patent has been filed outside the Kingdom for over eighteen months prior to the date of the patent application in Thailand (but patent has not been granted); or (5) an invention for which an application for a patent has been filed inside or outside the Kingdom and the application has been published before the date of filing the application in the Kingdom. However, disclosure which was due to the subject matter having been obtained unlawfully, or disclosure of the subject matter by the inventor including display of the inventor’s work at an international exhibition or, an official exhibition, and such disclosure was done within twelve months before the application for patent, shall not be deemed to be disclosure or availability to the public.

Filing requirements for an application (to be sent to resident agent):
1. Power of attorney, notarized by a Notary Public; a general power is accepted;
2. Assignment (if any), signed by both assignor and assignee; notarization and legalization are not required;
3. Statement of Applicant’s Right to Apply for a Patent (this requirement is only applicable if the applicant is also the inventor);
4. Specification in English that will then be translated into Thai according to the regulations. It is possible, however, to submit the specification in the original language in order to obtain an early filing date. In such cases, Thai translation must follow within ninety days;
5. Drawings, drawn or printed on A4 sized paper. However, where there are foreign characters in the drawings, they will have to be redrawn and retyped in the Thai phonetics by the patent agent;
6. Status and any other details regarding the applications filed in the home country and also other countries;
7. Certificate of Deposit of microorganism with an internationally accepted depositary Office should be submitted within ninety days from the filing day.

Note: all the submissions for filing a patent application in Thailand must be made in the Thai language. The contents of an application will include title of invention, brief description of drawings, if any, the best procedures in making the invention, utilization of the invention in industry, handicrafts, manufacturing, agriculture or commerce, one or more claims. Furthermore, other specific items such as details concerning the status of patent applications submitted outside of Thailand or exhibition of the invention arranged by the Thai government or in an international exhibition will have to be provided in the official application request form. All the significant documents, such as the power of attorney and assignment, may be submitted within ninety days from the date of filing, priority document within sixteen months from the first filing date.

Electronic filing: available. 

Electronic signatures: are accepted if the Notary Public clearly certifies the signature and the authority of the person signing the document. Scanned copies of wet signed documents are accepted, however, the Registrar may ask to review the original at a later date.

PCT applications: for this purpose, the Thai Patent Office is a PCT Receiving Office. Time limit for entering national phase: under both Chapters I and II: 30 months from the earliest priority date. The PCT took effect in Thailand on December 24, 2009. Accordingly, only PCT applications with an international filing date of December 24, 2009 and beyond are eligible to enter the national phase application in Thailand. There is no retroactive effect on those applications with an international filing date prior to the date on which the PCT took effect. Also, according to the current Ministerial Regulation, the Thai translation of the application text must be filed on the national phase entry date. Extension of time is not available. If an assignment has been recorded at the Bureau during the international phase, no further assignment document is required during the national phase. If the applicant is a non-resident, an agent is required by the Thai Receiving Office.

Examination Procedure

Formal examination: after the examination of a patent application for patentability and content of the application, the information in the application will be published.

Opposition: may be filed with the competent officer within ninety days after the publication of the application.

Substantive examination: upon request of the applicant. The request for novelty and inventive step examination has to be made within five years after the publication of the application, or in a case where an opposition and an appeal is filed, within one year after the final decision has been given, depending on which period expires later, otherwise the application shall be deemed abandoned.

Granting and Protection

Granting decision: based on the examination report as to the application’s conformity to the act, the Director General shall order a patent to be registered and granted to the applicant.

Appeal: must be made to the Board of Patents within sixty days after receipt of the notification from the Director General of his refusal to grant a patent.

Duration: twenty years from the date of application.

Annuities: the first annual fee shall be due at the beginning of the fifth year of the term of the patent and additional fees shall be payable annually thereafter. If a patent is granted after the beginning of the fifth year of the term of the patent, the first annual fee from the fifth year to the year of issuance of the patent shall be paid within sixty days after the granting of the patent.

Working: compulsory. Working of a patented product or process is required under the Patent Act. Although no provision explicitly states that the patented invention must be put to effective use within the country, the patentee has to make his/her patented product available in the market within a specified time to preserve his exclusive rights. At present, the Patent Act provides a provision of compulsory license as a measure to ensure the local working of the patented products or processes. To avoid compulsory licensing, the patentee may apply to the Director General of the Department of Intellectual Property for an entry to be made to the effect that any other person may obtain a license of his/her patent.

Compulsory licenses: after the expiration of three years from the grant of a patent or four years from the date of application, whichever is later, any person may apply for a compulsory license if it appears that a patented product or process is not produced or applied within the Kingdom, or that there is no sale of any patented product or product manufactured through the patented process, or there are some, but the price is unreasonably high, or the public demand is not met, without any legitimate reason.

Infringement: infringement may be punished by filing the complaint with the court in civil or criminal proceedings.

Penalties: (1) patent infringement: imprisonment not exceeding two years or a fine not exceeding Baht 400,000, or both; (2) petty patent infringement: imprisonment not exceeding one year or a fine not exceeding Baht 200,000, or both. Where an offense under the Patent Act has been committed by a legal entity, all officers or representatives of the legal entity, except those who can prove that such offense has been committed without his knowledge or consent, shall also be guilty of that offense.

Modification of Protection after Granting

Surrender of patent or claims: any patentee may surrender a patent or any claim or claims.

Cancellation of a patent is possible at any time for any invention which at the time of filing was not new, did not involve an inventive step, is not capable of industrial application, is not protected by the Patent Act, or was applied for by someone without the right to apply for a Thai patent. A petition to cancel an invalid patent may be submitted to the court by any person who has an interest in the patent or by the public prosecutor. The Director General may ask the Board to revoke the patent if (1) it appears, after two years of issuance of a license, that the licensing cannot effectively prevent or alleviate the following conditions: there is no production of the patented product or no application of the patented process in Thailand with no reason; the production of the patented product or application of the patented process is not sold or imported or sold at a reasonable price; and the Director General determines that such patent be revoked; (2) the license agreement was not made in written form and registered; the patentee or licensee will first be informed of such a determination, and be given sixty days to respond.

License: must be registered with the Patent Office; failure to do so may result of the cancellation of the patent.

Assignment: possible with a notarized power of attorney from assignee and a notarized deed of assignment bearing the signatures of both the assignee and the assignor.