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Cooley GO

What is a provisional patent application?

A provisional patent application (“provisional application”) is a document that is filed at the United States Patent and Trademark Office (USPTO) to establish an invention’s “priority date” – that is, to show that an applicant adequately possessed the invention described in the provisional application as of the provisional application’s filing date. To be most effective, a provisional application should describe the invention in enough detail for someone of ordinary skill in the art to make and use the invention without undue experimentation. A provisional application does not get examined by the USPTO, so it is the applicant’s responsibility to ensure that it describes the invention sufficiently. If the provisional application does not describe the invention thoroughly enough, then it may not establish a priority date for legal claims to the invention that are ultimately filed for examination in the U.S. or abroad.

Why should I consider filing a provisional application?

A provisional application is often an expedient way to establish a priority date for prospective worldwide patent rights for an invention without affecting the term of those rights.

When should I consider filing a provisional application?

  • Before a public disclosure (e.g., a conference presentation, poster session, department seminar, paper publication, or announcement);
  • Before a meeting with sponsors, collaborators, competitors, or investors; and
  • When the inventors have reduced their invention to practice (or have a good plan for how to reduce their invention to practice), but plan to continue working on it over the next year.

What should a provisional patent application include?

A provisional application may include any of a variety of materials (e.g., text, figures, graphs, charts, photographs) that describe the invention and how to make and use it. A provisional application should explicitly answer the following questions:

(1)   What is the invention?

(2)  How is the invention made?

(3)  How is the invention used?

U.S. law requires the provisional application to include comprehensive answers to these questions. These legal requirements are called the “written description” and “enablement” requirements and also apply to U.S. nonprovisional applications. Again, it is the applicant’s responsibility to ensure that provisional application meets these legal requirements to effectively establish an invention’s “priority date.”

TIP: Ask the inventors for every material that describes/supports their work on the invention, including theses, manuscripts, “Supplementary Materials” sections of journal papers, computer code (preferably with comments), laboratory notebooks, emails, and presentations.

TIP: Confirm that the invention being disclosed is actually new!  Check the inventor’s website for prior papers, abstracts, and presentations with similar sounding titles; search for press releases and internet postings on corporate websites, Twitter, Facebook, etc.; look for the inventors’ papers in Web of Science, Google Scholar, PubMed,, etc.; look for earlier patents and patent applications by the inventor(s) on Google Patents,, or another patent database; search for other relevant work by others as well.

Should a provisional application include patent “claims”?

Legally, a granted patent claim defines the invention for which an applicant has enforceable rights (e.g., to prevent others from using the claimed subject matter without permission).  Claims are granted by the USPTO in nonprovisional applications, which undergo examination by patent examiners for utility, novelty, nonobviousness, and compliance with the written description and enablement requirements.

A provisional application, on the other hand, is not examined, and thus does not have to include claims. Nevertheless, including claims in a provisional application offers several benefits. First, it provides the benefit of an earlier “priority date” for the later-filed nonprovisional application and the claims that will be examined in the nonprovisional application. Second, considering claims early in the provisional application drafting process is a useful exercise for shaping the legal definition of the invention. Third, the claim drafting process emphasizes the subject matter that should be described in detail in the provisional application to meet the “written description” and “enablement” requirements.

TIP: Including even a modest number of claims in a provisional application focuses the effort and may provide stronger priority benefits for any follow-on nonprovisional applications.

Who should be named as an inventor on a provisional application?

Under U.S. law, an inventor is someone who “contributes to the conception” of the inventive subject matter in a provisional application. Someone who has only reduced the inventive material to practice (without making any conceptual contribution) should not be named as an inventor. Inventorship is not necessarily the same as authorship of an academic paper.

TIP: Many journals now ask authors to include statements identifying their contributions, e.g., “J.S. and R.B. conceived of the project. A.T. fabricated the samples …” These statements often provide clues as to who should be named as an inventor.

Who owns the invention?

Under U.S. law, patent rights accrue to the inventors. But most inventors are obligated to assign their patent rights to their employers by virtue of their employment agreements or institutional intellectual property policies.

Similarly, an inventor employed elsewhere, such as a contractor or collaborator, may be obligated to assign his or her patent rights to his or her employer. If the provisional application names inventors from two entities, then both entities may have undivided rights in the provisional application.

TIP: Patent claims can inform the inventorship (and the ownership) of a provisional application. This is another good reason to include patent claims in a provisional application.

TIP: Obtain and record assignments from the inventors as soon as possible. This ensures that the assignee can file continuing and PCT applications, grant licenses, etc. It also eliminates potential uncertainty about ownership that could arise in diligence or litigation.

Where was the invention made?

If the invention was invented in another country, it might be necessary to get a foreign filing license from the other country’s patent office before filing a U.S. provisional application. In some cases, it might be appropriate to file a patent application in the other country first, then file a U.S. nonprovisional application that claims priority to the foreign patent application.

If the invention was invented elsewhere, either in the U.S. or abroad, another entity may have patent rights in the invention, e.g., because its employees are inventors or because it provided facilities or services to the inventor(s).

TIP: For cases involving inventors from another entity, consider executing a license or joint research agreement with the other entity to reduce the risk of dispute about ownership and control of jointly developed intellectual property.

When do I have to “convert” my provisional application?

An applicant must “convert” the provisional application by filing a nonprovisional application within one year of the provisional application’s filing date. Of course, an applicant can always file a nonprovisional application before the anniversary of the provisional application’s filing date. This starts the examination process sooner, but also begins the term of any patent that might issue from the nonprovisional application.

Can I file more than one provisional application for the same invention?

Yes. An applicant can file as many provisional applications as desired for a single invention.

TIP: For on-going projects, it often makes sense to file provisional applications in a thoughtful, early, and often manner, where each provisional application represents an additional advance or milestone. A series of thoughtful, early, and often provisional applications can provide the earliest possible priority date for each advance. The concepts disclosed in these provisional applications can be filed in a single nonprovisional patent application before the first provisional application in the series expires.