Which International Search Authority Should A PCT Applicant Choose?

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A Patent Cooperation Treaty (PCT) is an international agreement that allows patent applications to seek protection for their inventions in multiple countries through a single application. One of the key steps in the PCT process is the selection of an International Search Authority (ISA). As a PCT applicant, choosing the right international search authority is crucial.  

The International Search Authority (ISA) is an organization designated by the Intellectual Property Organization (WIPO) to perform international searches on patent applications filed under the PCT. The primary role of the ISA is to assess the patentability of the invention and identify relevant prior art that may affect the novelty and non-obviousness of the invention. The ISA conducts a search on published patent and non-patent literature to identify relevant prior arts and prepares an international search report (ISR) stating a written opinion on the patentability of the invention. 

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The PCT system currently has 24 international search authorities and choosing one can be an overwhelming task for an applicant. Following are the International Searching Authorities as per the agreements with the International Bureau of WIPO. 

Austrian Patent Office 

Eurasian Patent Office 

Indian Patent Office 

Intellectual Property Office of Singapore 

Australian Patent Office 

Egyptian Patent Office 

Japan Patent Office 

Turkish Patent and Trademark Office 

National Institute of Industrial Property (Brazil) 

European Patent Office (EPO) 

Korean Intellectual Property Office 

National Intellectual Property Authority, State Enterprise “Ukrainian Intellectual Property Institute (Ukrpatent)” 

Canadian Intellectual Property Office 

Spanish Patent and Trademark Office 

Intellectual Property Office of the Philippines 

United States Patent and Trademark Office (USPTO) 

National Institute of Industrial Property of Chile 

Finnish Patent and Registration Office (PRH) 

Federal Service for Intellectual Property (Rospatent) (Russian Federation) 

Nordic Patent Institute 

China National Intellectual Property Administration (CNIPA) 

Israel Patent Office 

Swedish Intellectual Property Office (PRV) 

Visegrad Patent Institute 

The following are some important points to remember:  

Quality and Reputation of the Authority 

The quality and reputation of the ISA can have a significant impact on the outcome of the search and the ultimate success of the patent application. It is important to select an authority that has a track record of conducting thorough and accurate searches, and that is respected within the international patent community. The EPO has historically provided a higher rate of positive search reports than KIPO, CNIPA, and USPTO. Also, one can expect EPO examiners to find more relevant prior arts and hence more claim rejections in view of a tough examination. 

Technical Expertise

Another important factor to consider is the technical expertise of the search authority. The search authority should have expertise in the relevant field of technology to provide a comprehensive search report.  

Turnaround time 

The time taken by the search authority to provide the ISR can also be a significant factor for applicants. Some search authorities are known to provide faster turnaround times, which can be crucial for those who want to file a patent application quickly. The USPTO offers expedited search options for an additional fee, which can be useful for applicants seeking a faster turnaround time. 


The search fees charged by different search authorities can vary significantly. Applicants need to consider their budget and choose a search authority that provides good value for money. The Russian IP office is the cheapest while the EPO is the most expensive ISA for small entities, whereas, for larger entities (i.e., a company with more than 500 employees), USPTO is the most expensive ISA, as USPTO is the only ISA where government fees for a large entity are twice as much as those for a small entity
The ISA options sorted by cost from highest to lowest for small entity applicants include: 

  • European Patent Office (EPO) 
  • Australian Patent Office (IPAU) 
  • Intellectual Property Office of Singapore (IPOS) 
  • Japan Patent Office (JPO) 
  • Israel Patent Office (ILPO) 
  • US Patent and Trademark Office (USPTO) 
  • Korean Intellectual Property Office (KIPO) 
  • Russian Federal Service for Intellectual Property (Rospatent) 


The language of the search report should also be considered when choosing an international search authority. The search report will be written in the language of the search authority, which may not be the applicant’s native language. Choosing a search authority that offers a report in the applicant’s preferred language can make it easier to understand & respond to the report. 

Regional Coverage

Some search authorities have regional coverage and may be more familiar with the local patent laws and practices. For instance, the European Patent Office (EPO) is known for providing a comprehensive search report for patents seeking protection in Europe. 
Considering these factors, applicants can make an informed decision when choosing the international search authority for their PCT application.

Here Are Some Of The Popular Search Authorities The Applicants Used For The PCT Application And Their Strengths:

  1. European Patent Office (EPO)

    The EPO is a well-respected authority and is known for its comprehensive and accurate search report which covers most of the European countries. The EPO is also known for its fast turnaround time and offers search reports in multiple languages. The fees charged by the EPO are generally considered reasonable. 

  2. Korean Intellectual Property Office (KIPO) 

    The KIPO is known for its technical expertise in electronics, semiconductors, and information technology. The KIPO search reports are available in English, and Korean. 

  3. Japan Patent Office (JPO)

    The JPO is known for its expertise in mechanical engineering and information technology. The JPO search report is available in English, and Japanese. 

  4. United States Patent and Trademark Office (USPTO)

    The USPTO is known for its expertise in computer science, biotechnology, and medical devices. The USPTO search report is available in English.  

  5. China National Intellectual Property Administration (CNIPA)

    The CNIPA is known for its expertise in electronics, communications, and computer science. The CNIPA search report is available in Chinese and English. 

Further, the choice for the ISA also depends on the specific needs, goals, or constraints of the applicant. For example, if you want a thorough search for your patent application within time and money is not a problem, you should choose EPO. It not only provides a comprehensive search report but also provides an easy green flag to your application when entered in the European national phase.  

In another example, if multiple inventions have been claimed in a single application and the applicants want to search for all the inventions but are low on budget, KIPO will be the best option as it costs less than EPO. The EPO charges extra bucks for searching more than one invention claimed in a single application. Further, KIPO is also useful for new start-ups that are tight on budget and are unsure about their future but want to file multiple PCT applications. Also, if the main goal of the applicant is to buy time by deferring deadlines, the Russian Federation offers the lowest cost. Thus, the choice of the ISA may vary depending on the specific needs of the applicant and/or PCT application.

The following list presents the International Searching Authorities (ISA) selected by United States-based applicants for PCT applications, as per the WIPO IP statics data center: 

  1. European Patent Office (EPO): 41.2% 
  2. United States Patent and Trademark Office (USPTO): 40.8% 
  3. Korean Intellectual Property Office (KIPO): 14% 
  4. Federal Service for Intellectual Property (Rospatent) Russian Federation: 1.7%


In conclusion, the choice of the international search authority can significantly impact the patent application process. Applicants should consider the language, technical expertise, turnaround time, cost, and regional coverage as well as assess the specifics related to the PCT application before choosing a search authority. It is essential to select an authority that offers good value for money and can provide a comprehensive search report to ensure the best possible outcome for a patent application. 

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