Applying for a patent


What are the criteria for patentability in your jurisdiction?

Under the Patent Act 1979 (as amended in 1999), three types of patent can be protected in Thailand:

  • invention patents;
  • petty patents; and
  • design patents.

Invention patents An invention patent must fulfil the patentability requirements under Section 5 of the Patent Act. To be patentable, an invention must:

  • be new;
  • involve an inventive step; and
  • be capable of industrial application.

The higher threshold for invention patents – compared to design and petty patents – is commensurate with a longer exclusivity period. Design and petty patents grant exclusivity to the inventor for 10 years, whereas invention patents offer an exclusivity period of 20 years from the date of filing the patent registration application.

Invention patent applications are filed with the Department of Intellectual Property. Once granted, proper fees must be paid to ensure the patent’s validity for the 20-year period.

Petty patents Where an invention does not involve an inventive step, the invention may be eligible for a petty patent if it is new and capable of industrial application.

A petty patent (also known as a utility model in other countries) can be granted for a new invention that is capable of industrial application but lacks a high level of inventive novelty. The advantage of a petty patent is that the registration and approval process is shorter because, unlike invention patents, the novelty or inventive component is not examined before registration. The total possible exclusivity term for a petty patent is 10 years. The initial patent is valid for six years, with two possible extensions of two years each, provided that the proper fees are paid to maintain the patent’s validity.

Petty patents are the preferred route of protecting inventions for manufacturing companies and inventors of obvious or less complicated inventions due to the relatively simple requirements, compared to invention patents. Not having to fulfil the inventive step criteria means that a petty patent applicant can file more patents for new, simple inventions, thereby allowing the company or patentee to build up a large patent portfolio easily.

Design patents A design may be eligible for design patent if it is new and industrially applicable. 

Design patents are granted based on the ornamental aspects or aesthetics of an article, including features that pertain to the shape, configuration or pattern. As such, design patents may be granted for new qualifying three-dimensional designs or designs with a two-dimensional element. In Thailand, design patents are popularly sought by both Thai and foreign patentees. The Department of Intellectual Property grants design patents 10 years of protection from the date of filing.

Particular types of company – especially in design-heavy industries – often apply for either design patents or invention patents. For example, car manufacturers, furniture designers, and beverage companies routinely seek design patent protection for new car models, furniture and bottles, respectively.

The main advantage of a design patent, compared to an invention patent, is the less demanding efficiency requirements of the patent application. Design patents have only two requirements: that the patent be new and capable of industrial application.

The following focuses mostly on invention patents.

What are the limits on patentability?

Sections 9 and 65decies of the Patent Act apply to invention patents and petty patents, and exclude the following inventions from patentability:

  • natural micro-organisms and any component of micro-organisms, plants or extracts from animals or plants;
  • scientific and mathematical methods and theories;
  • data systems for an operation of a computer (computer programs);
  • methods of diagnosis, treatment or cure of human and animal diseases; and
  • inventions contrary to public order, public health and morals and general welfare.

Patent applications can also be challenged if:

  • the patent owner is not the true inventor or has no right to file an application; or
  • a disclosure of an invention to the public was made more than 12 months before the filing of the patent application. This scenario precludes an applicant from obtaining an invention patent or a petty patent.

For design patents, designs that are purely functional, contrary to public order or prescribed by a royal decree are not patentable.  

To what extent can inventions covering software be patented?

Computer programs or software cannot be patented under Sections 9 and 65decies of the Patent Act. However, inventions relating to devices or machines controlled by software, or processes or algorithms for controlling devices or computers, may be patentable. Software-related inventions involving only computer source code cannot be patented but may be protected as a copyrighted literary work or a trade secret. 

To what extent can inventions covering business methods be patented?

A business method cannot be patented as it is not considered to be an invention as defined in Section 3 of the Patent Act. However, a business method carried out by a computer can be considered as a software-related invention that may be patentable. 

To what extent can inventions relating to stem cells be patented?

Stem cells are considered to be an animal extract, which is a non-patentable subject matter under Section 9 of the Patent Act. However, processes for the production or use of stem cells may be patentable.

Are there restrictions on any other kinds of invention?

Only the restrictions outlined above.

Grace period

Does your jurisdiction have a grace period? If so, how does it work?

Sections 6 and 65decies of the Patent Act provide grace periods relating to patent applications. A 12-month grace period applies before the date of filing an application for an invention patent or a petty patent. Within this 12-month period, the disclosure of details of the invention is not considered to destroy the novelty of the invention, provided that the disclosure was made by the inventor or made as a result of the inventor displaying the invention at an international or official exhibition.

Under Section 19, an applicant who exhibited an invention at an government-sponsored or authorised exhibition held in Thailand who then later files a patent application for the invention within 12 months of the opening date of the exhibition is considered to have filed the application on the opening date of the exhibition.

There is no grace period for design patent and petty applications.


What types of patent opposition procedure are available in your jurisdiction?

Thailand operates a pre-grant opposition system. Under Sections 31 and 65 of the Patent Act, any interested party may oppose the grant of an invention patent or a design patent within 90 days of the application being officially published in the Patent Gazette.

Pre-grant oppositions are not available for petty patent applications because such applications are published and granted at the same time. This is a source of concern for many international patentees as they often need to challenge the validity of petty patents in court.

Apart from oppositions, are there any other ways to challenge a patent outside the courts?

After the 90-day opposition period post publication, any interested party may provide informal third-party observations to the Thai Patent Office, which usually involves presenting prior art and reasoning as to why a patent application should not be granted to the examiner for consideration during the substantive examination period. This informal procedure, which is widely used by local patent practitioners, helps examiners raise invalidity arguments and is an important factor that can delay the grant of a patent application that, ultimately, may lead to the refusal of some applications. 

How can patent office decisions be appealed in your jurisdiction?

If the Thai Patent Office rejects an invention patent or petty patent application, the applicant may appeal the rejection decision to the Board of Patents within 60 days of the decision. If the board affirms the rejection decision, the applicant may file an appeal with the IP & IT Court within 60 days of receiving notice of the board’s decision.

Timescale and costs

How long should an applicant expect to wait before being granted a patent and what level of cost should it budget for?

In a straightforward case, the period from filing to grant is approximately four to five years for an invention patent, and one to two years for a design or petty patent. The entire process from filing to grant may cost up to $2,000 for an invention patent and $1,500 for a design or petty patent. These costs exclude the cost of drafting or translating the application. Patent applicants can also use different means to speed up the grant of their patent application, such as the Patent Prosecution Highway system or the Association of Southeast Nations Patent Examination Cooperation system. Another important factor to improve examination speed is to provide Thai patent examiners with copies of foreign corresponding granted patent applications and to amend claims to match the claims accepted in another jurisdiction (eg, Japan, the United States or the European Union).

Enforcement through the courts


What are the most effective ways for a patent owner to enforce its rights in your jurisdiction?

Most patent infringement cases can be settled by sending a cease and desist letter or proposing a patent licence to the infringer. Alternatively, a patent owner can enforce its patent rights through criminal and civil proceedings. While criminal proceedings are more cost-effective and less time-consuming, civil proceedings are more suited to patent enforcement where the patent owner is seeking to obtain a permanent injunction, collect licences or receive substantial damages. Moreover, criminal proceedings attract low fines, with the maximum being Bt400,000 (approximately $12,000) for invention patents and Bt200,000 (approximately $6,000) for design or petty patents. Out-of-court settlements through alternative dispute resolution methods, such as arbitration and mediation, are also popular because both parties usually have an interest in avoiding disclosure of their dispute settlements. Some patentees have raised concerns about the timeframe and costs of patent litigation proceedings before the Thai courts. The lack of specialised judges to handle complex patent litigation cases is also a source of concern.

Only the patent owner or the transferee of a patent can bring an infringement action in the Central Intellectual Property and International Trade Court (the IP & IT Court).

What scope is there for forum selection?

There is no room for forum selection in relation to patent rights violation cases because IP cases fall under the jurisdiction of the Intellectual Property and International Trade Court. Infringement suits are filed at the IP & IT Court, which has exclusive jurisdiction to adjudicate criminal and civil cases involving IP rights in Thailand. Appeals to the IP & IT Court’s decision are made to the Court of Appeal for Specialised Cases, and that court’s decisions can be appealed further to the Supreme Court. The Supreme Court’s decision is final. 


What are the stages in the litigation process leading up to a full trial?

In general, the following stages occur before a full trial:

  • The patent owner conducts a private investigation to collect evidence of infringement.
  • The patent owner sends a cease and desist letter to the alleged infringer informing the party of patent validity, ownership and requesting that the infringer ceases infringing the patent. If no reply is received, a follow-up letter may be sent to the infringer after expiry of the prescribed period.
  • Both parties enter into direct negotiation or mediation to settle the infringement case.
  • If no settlement is reached within the deadlines, the patent owner initiates a civil action against the infringer by filing a written complaint with the IP & IT Court and serving it to the infringer, and the court summons the infringer. In return, the infringer must file an answer to the complaint with the court and serve a copy of the answer to the patent owner.
  • The court sets a hearing date in order to determine whether both parties are committed to litigation. During the hearing the court will set out the issues to be tried. The court will also determine the number of witnesses allowed by each party, the witness testimony hearing dates and key deadlines for pre-trial procedures, including:
    • the conduct of experiments to prove infringement;
    • submission of each party's evidence lists; and
    • submission of evidence particulars.
  • Both parties prepare and submit written testimonies, supporting documents and evidence, and a list of witnesses who will testify before the court.
  • The court sets a schedule for discovery and trial on the patent infringement issues.
  • A decision is usually made within one month of the final witness hearing date.

How easy is it for defendants to delay proceedings and how can plaintiffs prevent them from doing so?

The defendant may attempt to delay proceedings by requesting extensions of individual deadlines or unreasonable postponements of hearing, or by raising procedural issues concerning the handling of the case that require decisions by the court. The plaintiff can oppose any such request, and the court will then consider whether the request is reasonable. Patent litigation cases are usually decided within 12 to 18 months of filing a complaint. In some cases, the court may consider granting more time to the plaintiff or defendant if the party is awaiting information being sought by subpoena.

How might a party challenge the validity of a patent through the courts in anticipation of a potential suit for infringement being issued against it?

A party anticipating an infringement suit would typically attempt to challenge the validity of the patent at issue before the IP&IT Court by filing a patent invalidity case and become a plaintiff. While this would not prevent an infringement suit, the IP&IT Court would usually consider the invalidity case first before making a decision in the infringement suit.

In case an infringement suit has already been initiated, the defendant can claim in its defence that the patent is invalid. The defendant can file a counterclaim for patent invalidity with the court alongside the answer to the infringement complaint, and serve a copy of the counterclaim on the plaintiff. The plaintiff must file an answer to the counterclaim with the court and serve a copy of the answer on the defendant. Alternatively, the defendant may file an invalidity action against the plaintiff’s patent to bring about a new suit. The judge appointed in the infringement case is usually also appointed in the invalidity case and, after consulting with the parties, may decide to merge the cases. 

At trial

What level of expertise can a patent owner expect from the courts?

The IP & IT Court has professional judges with expertise in intellectual property, but no judges have specialised technical backgrounds. In cases involving high technology, an external technical expert appointed by the court will serve as an associate judge to assist the professional judges with the technical aspects of the case. 

Are cases decided by one judge, a panel of judges or a jury?

Patent litigation cases will be decided by a panel of judges consisting of at least two professional judges and one associate judge.

If jury trials do exist, what is the process for deciding whether a case should be put to a jury?

Thailand does not have jury trials.

What role can and do expert witnesses play in proceedings?

In the IP & IT Court, expert witnesses play a vital role in patent litigation cases, particularly in cases where the invention involves complex technology. The primary role of expert witnesses is to offer testimony on various issues, for example:

  • aiding the judges in understanding the invention in tutorial or expert witnesses hearings;
  • explaining the meaning of technical terms as they would be understood by a person skilled in the art;
  • explaining the prior art;
  • establishing infringement or non-infringement;
  • proving or rebutting invalidity arguments;
  • explaining the patent prosecution practices of the Thai Patent Office;
  • calculating the amount of damages.

Does your jurisdiction apply a doctrine of equivalents and, if so, how?

At present, there is no clear statutory provision concerning the application of the doctrine of equivalents. However, the doctrine of equivalents may be raised under the interpretation of Section 36bis(2) – that is, in some circumstances a product or process can be held to infringe a claim even where one or more of the recitations in the claim is not met. The doctrine of equivalents is intended to apply to those that make unimportant and insubstantial changes and substitutions in the patent which add nothing to the invention, but serve only to evade the literal scope of the claim language.

The IP & IT Court has recognised the doctrine of equivalents in Aventis Pharma v Bioscience (Red Case Tor Por 79/2548). The court requires the ‘non-essential part’ test and the ‘ease of interchangeability’ test to be fulfilled in order to find infringement under the doctrine of equivalents.

Is it possible to obtain preliminary injunctions? If so, under what circumstances?

Preliminary injunctions are available under Section 77bis of the Patent Act, but are rarely granted. A patent owner may apply to the court for an injunction if there is clear evidence that a person has committed or is about to commit an infringing act. 

How are issues around infringement and validity treated in your jurisdiction?

There is no bifurcation; the judge has the discretion to deal with infringement and validity in the same suit or separately. 

Will courts consider decisions in cases involving similar issues from other jurisdictions?

Foreign court decisions in similar cases are generally unenforceable in Thailand, but may be recognised as proof of a claim adjudicated abroad.

Damages and remedies

Can the successful party obtain costs from the losing party?

Yes; however, the value of the costs is at the judge’s discretion.

What are the typical remedies granted to a successful plaintiff?

The following remedies may be granted:

  • Permanent injunction (Section 77bis) – the IP & IT Court will grant a permanent injunction to the patent owner following a finding of patent infringement. However, the scope of the court order for a permanent injunction is limited to the types and extent of injunctive relief requested by the patent owner in the case.
  • Monetary remedies (Section 77ter) – if the court finds that there is patent infringement, it will order the infringer to pay compensation for damages to a patent owner in an amount as deemed appropriate by the court, taking into consideration the seriousness of the damages, the loss of benefits and the expenses necessary to enforce the rights of the patent owner.
  • Destruction of infringing goods (Section 77quater) – the court can order the destruction of goods found to infringe a patent.

A patent owner can also seek publication of the court’s decision and a recall order, which is within the discretion of the court to grant.

Under Section 85 of the Patent Act, if the patent owner also brings a criminal action against the infringer, the infringer may face a criminal penalty of up to Bt400,000 (approximately $10,000) and imprisonment for up to two years. 

How are damages awards calculated? Are punitive damages available?

The court generally awards only the actual damages suffered as a result of the infringing activities. Punitive damages are not available. 

How common is it for courts to grant permanent injunctions to successful plaintiffs and under what circumstances will they do this?

In most cases where the court finds patent infringement, it grants a permanent injunction to a patent owner provided that it is within the scope of remedies claimed by the patent owner in the pleadings. In special circumstances, the court may deny or limit the grant of a permanent injunction.

Timescale and costs

How long does it take to obtain a decision at first instance and is it possible to expedite this process?

The entire process from submission of the pleadings to judgment by the IP & IT Court in a patent litigation case is between 18 and 36 months. This process may not be expedited due to the volume of cases pending before the court.

How much should a litigant plan to pay to take a case through to a first-instance decision?

The cost of taking a case through civil proceedings at the IP & IT Court, the court of first instance, in a patent litigation case starts from $30,000 for a simple case, and may reach more than $100,000 for a highly technical case involving lots of evidence and many witnesses. For criminal proceedings, these costs are much lower – around $18,000 for a simple case.


Under what circumstances will the losing party in a first-instance case be granted the right to appeal? How long does an appeal typically take?

A losing party in a patent litigation case before the IP & IT Court can file an appeal against the decision to the Court of Appeal for Specialised Cases. In criminal cases, the appeal decision can be appealed further to the Supreme Court. In civil cases, the appeal decision is deemed final but the parties may ask the Supreme Court to grant permission to appeal the decision further. The appeal process takes between eight and 12 months from the submission of the appeal to the time of judgment.

Options away from court

Are there other dispute resolution options open to parties that believe their patents to be infringed outside the courts?

Alternative dispute resolution (ADR) methods such as arbitration and mediation are available to settle patent infringement claims outside the courts. The Department of Intellectual Property and the IP & IT Court have established their own ADR centres which are highly recommended to settle smaller disputes, particularly when lawyers’ fees are likely to be high if a full infringement action is brought before the courts. Few law firms in Thailand have experience of handling patent litigation cases, so it is highly recommended to check the credentials of litigators appointed in a patent litigation case and explore all of the available options with them before going to court.