Provisional patent applications in the US: A tool to protect your invention

What is a provisional patent application?

A provisional patent application is a temporary form of a United States patent application that establishes a filing date but does not mature into a regular utility patent application.

A provisional application must be replaced with a regular patent application claiming priority to the provisional application within one year of the initial filing date.

Unlike regularly utility applications, provisional applications are not examined and do not require an oath or declaration, or an information disclosure statement.

Using a provisional patent application to protect your invention

US provisional patent applications can be a useful strategic tool when seeking protection for a new invention.

A provisional patent application establishes a filing date and acts as a placeholder for the subsequent filing of a regular utility patent application. Note that provisional patent applications exist only in the US, not Canada.

Benefits of provisional applications

  1. A significant benefit of filing a provisional application is that the patent term for a regular US patent application claiming priority to a provisional application is calculated based on the filing date of the regular patent application (20 years from filing of the regular application). This effectively extending the patent term by up to one year if the regular application is filed on the one-year anniversary of the provisional filing date.
  2. A provisional patent application is not subject to examination by the United States Patent and Trademark Office (USPTO) and lapses after one year from its filing date, never maturing directly into a regular patent application. If the provisional application is abandoned without the filing of a regular utility patent application, the abandoned provisional application is not published by the USPTO. Conversely, if a regular patent application is filed within one year and claims priority to the provisional application, the provisional patent application becomes part of the file history of the regular patent application.
  3. The most widely recognized benefit of a provisional patent application is the low government filing fee. In 2021, the fee for filing a provisional patent application as a small entity was US$204. The reason for this minimal cost is that the application is not examined by a US Patent Examiner, so there is no search or examination carried out. This low fee can be highly beneficial when seeking to protect a technology with an unproven market potential. However, the low government fee and the fact that provisional patent applications can be filed without claims often tempts inventors to file “quick and dirty” provisional patent applications, with the intent of adding the additional disclosure and supporting material when filing a regular application one year later. This strategy, while appealing at first glance, can carry high risks and often put a patent in serious jeopardy.

Risks of filing an incomplete provisional application

Inventors may be surprised to learn that provisional patent applications are subject to the same statutory requirements as a regular patent application. Specifically, in order to support the claims in a US regular utility patent application claiming priority to a provisional application, the specification of the provisional application must have provided the following:

  1. A written description of the invention
  2. A detailed disclosure, including figures that illustrate the claimed invention with sufficient clarity that a person skilled in the related art could practice the invention without undue experimentation
  3. An explanation of the best mode of practicing the invention known to the applicant at the time of filing

A common scenario involves the filing of a provisional patent application shortly before a public disclosure of the invention is to be made.

However, if the provisional application does not adequately support the claims of the regular utility application filed one year later, the inadequate disclosure can result in the forfeit of patent rights outside of Canada and the United States.

Since Canada and the United States have a one-year grace period with regard to public disclosures, it is still possible to obtain protection in these jurisdictions after having publicly disclosed an invention.

In contrast, in most other jurisdictions, the disclosure of the invention after the inadequate disclosure in the provisional application could result in some, if not all, claims being invalidated.

To make matters worse, the applicant may not be aware of the forfeiture, and a foreign patent examiner may not examine the provisional application to ascertain the quality and sufficiency of the initial disclosure.

The result may be that the claims of the patent are invalidated at a much later stage during litigation, long after the applicant has paid tens of thousands of dollars developing a broad foreign portfolio based on the initial provisional application.

File complete provisional applications

For the reasons outlined above, it is highly recommended that inventors seek a qualified patent agent to draft a complete patent application when filing a provisional patent application.

This ensures that the original specification properly supports the claims that will eventually form the basis of the regular application.

Occasionally, there may simply not be enough time to draft a complete application before a public disclosure is made. In such cases, it is usually best to employ a common sense approach and file the most complete application possible given the time constraint, following up shortly afterward with a complete filing.

When properly executed, filing an initial provisional patent application can yield many benefits.

By preparing a provisional application as a complete application that fully supports the claimed invention, inventors can enjoy the advantages of filing a provisional application while mitigating the risks involved.

Written by Stephen W. Leonard, Ph.D., registered Canadian and US Patent Agent at Hill and Schumacher,