Key Takeaways
- Thailand offers three options: the invention patent (20 years), the petty patent / utility model (up to 10 years, faster and cheaper), and the design patent (10 years).
- Thailand requires worldwide novelty. Any public disclosure anywhere before filing can destroy your rights. File before you publish, sell, or present.
- Thailand is first-to-file and a member of the PCT (since 2009), so an international PCT application can enter Thailand.
- For an invention patent, you must request substantive examination within five years of publication, or the application lapses.
- The petty patent is a fast route for incremental innovations: no inventive-step test and no full examination.
Patents in Thailand are governed by the Patent Act B.E. 2522 (1979), as amended up to B.E. 2542 (1999), and administered by the Department of Intellectual Property (DIP). A long-awaited amendment, to streamline examination and join the Hague system for designs, is under parliamentary consideration but is not yet law. The rules below are those currently in force.
The Three Types of Protection
Invention patent. For a new product or process. Protects for 20 years from the filing date. Requires novelty, an inventive step, and industrial applicability.
Petty patent (utility model). For smaller or incremental inventions. Requires novelty and industrial applicability but no inventive step, and is granted without full substantive examination, so it is faster and cheaper. Lasts 6 years from filing, renewable twice for two years each, up to 10 years.
Design patent. Protects the ornamental appearance of a product, such as its shape, configuration, or pattern. Lasts 10 years from filing.
File Before You Disclose
Thailand applies absolute novelty. Any public disclosure anywhere in the world before your filing date, including your own presentations, sales, or publications, can defeat the application. Treat the invention as confidential until you have filed. This is the single most common way good inventions lose protection.
What Cannot Be Patented
Scientific and mathematical theories, computer programs as such, methods of diagnosis or treatment of humans or animals, naturally occurring microorganisms, plants and animals, and inventions contrary to public order or morality.
First-to-File and the International Route
Priority goes to the first to file, not the first to invent. Thailand is a member of the Paris Convention and the Patent Cooperation Treaty (PCT, effective 24 December 2009). A PCT international application can designate Thailand, and a Paris Convention priority claim is available within 12 months of a first foreign filing. This lets you coordinate Thai protection with filings abroad.
The Five-Year Examination Deadline
For an invention patent, the application is published, and you must then actively request substantive examination within five years of the publication date. Miss it and the application is deemed abandoned. This is a frequent and costly oversight, so the deadline should be diarised from the moment of publication. Petty patents do not require this step.
Maintenance
Annual fees are payable to keep an invention patent in force, beginning in the fifth year. Lapsed fees can lead to the patent ceasing to have effect.
Practical Tips
- File before any public disclosure; absolute novelty is unforgiving.
- Consider a petty patent for incremental improvements or where speed matters.
- Use the PCT or a Paris Convention priority claim to align Thai filing with filings abroad.
- Diarise the five-year deadline to request examination of an invention patent.
How Dej-Udom & Associates Can Help
Our Intellectual Property and Patent team handles patentability assessments and novelty searches, drafting and filing of invention, petty, and design applications, PCT national-phase entry into Thailand, examination responses, annuity management, and enforcement against infringement. We act for both Thai and international applicants across technology, manufacturing, consumer, and life-sciences sectors.
Disclaimer: This publication is intended for general informational purposes only and does not constitute legal advice. For advice tailored to your circumstances, please contact Dej-Udom & Associates directly. Figures are drawn from the Patent Act B.E. 2522 (as amended up to 1999) and the official Department of Intellectual Property (ipthailand.go.th); a draft amendment is pending and may change several of these rules.