A Decision Guide for Filing International Patent Applications for Multiple Inventions

Companies have two choices for meeting the PCT patent application filing requirements when they have multiple pending provisional applications. We go through the pros and cons for each approach.

A company engaged in research and development will often create multiple related inventions within a year, and file a separate provisional application for each invention within that year. To obtain patent protection internationally for those inventions, the company must then file a PCT application for each invention within one year of the provisional application filing. The company has a choice to (a) file one PCT application that describes all of the inventions within one year of the earliest provisional application, or (b) file a separate PCT application for each invention within one year of each provisional application. There are advantages and disadvantages for each approach.

For example, a company files provisional applications on January 1 and November 1, 2017, describing two different but related inventions. The company can then (a) file one PCT application by January 1, 2018 that describes both inventions, or (b) file two separate PCT applications, by January 1, 2018 and November 1, 2018, each only describing one invention. Here are the advantages and disadvantages of filing one PCT application on January 1, 2018 that describes both inventions, rather than filing two separate PCT applications, each describing only one invention, on January 1, 2018 and November 1, 2018.

Advantages of filing one application that describes both inventions

Save filing fees

By filing one application that describes both inventions, the company saves money by only paying one filing fee, rather than fees for two PCT applications. Although the PCT will only normally provide a search on one of the inventions, the company can pay a fee to have both inventions searched.

Flexibility to pursue either or both inventions

If the company ends up developing only one of the two inventions, that invention can be pursued with this application; there will not be a second “wasted” application that is of no interest to the company.

Establish that the two inventions lack unity of invention

When both inventions are listed in the PCT application, the examining patent office will decide whether the two inventions are different enough from each other that one invention is patentably distinct from the other invention. This can be important if there is prior art that describes one of the inventions but not the other.  If the two inventions are patentably distinct, the company could still obtain patent protection for the invention for which there is no prior art.

Disadvantages of filing one application that describes both inventions

Lose patent term for the later invention

In our example, if patents are obtained for both inventions, both patents will expire January 1, 2038. However, if a separate PCT application was filed for each invention, the patent for the second invention will expire November 1, 2038, extending the life of that patent by 10 months over the one PCT approach.

The description of the later invention is published sooner

In our example, the PCT application will publish in July 2018. This will reveal both inventions to the public, giving competitors an early view of the second invention. Also, in the U.S., the publication becomes prior art for the company one year after publishing (here, July 2019), and that prior art could prevent the company from obtaining patent protection for a later invention. By contrast, if a separate PCT application is filed for each invention, the PCT for the second invention will publish in May 2019, keeping the second invention confidential for 10 months longer than the one PCT approach.  That second PCT will also become prior art for the company 10 months later, in May 2020, one year after the second PCT publishes.

Unnecessary translation costs

If the company wishes to enter multiple national phases with one invention but not the other invention, they will nonetheless have to translate the specification that describes both inventions for national phases requiring translations (e.g., China, Japan), incurring unnecessary translation costs.

This decision process can be complex. Companies that have multiple inventions within one year should discuss with their attorney these important considerations for filing a single or multiple PCT applications for those inventions.