Challenges to Your Patent


After you have achieved the award of a patent, you may still be subject to challenge from competitors.  Stated differently, there may be challenges to your patent.

Post Grant Review

Part of the America Invents Act or AIA the USPTO established a procedure called a Post Grant Review. The procedure gives third parties up to 9 months after the grant of your patent to challenge the award. The goal of the petition is to cause the USPTO to cancel your newly allowed patent claims. This in effect, cancels your patent.  Also see article Challenging Junk Patents. 

Post Grant Review is intended to be a rapid process.  The process, however, contains sufficient complexity to require legal support.

Grounds For Patent Challenge

The grounds of justification for the petition seeking the cancellation of all claims are very broad.

The petition may be based upon your patent claiming patent-ineligible subject matter. (This can be especially disheartening after you have just fought this battle with the examiner and the Section 101 rejections.)

Also the patent can be challenged again on issues of novelty (Section 102) or obviousness (Section 103). The challenger can bring new prior art references different than the references cited by the examiner. Your patent can be challenged on the basis that the specification does not adequately inform a person skilled in the art how to use or make your invention. (This is the enablement burden required even of provisional applications.)

Another basis is that the specification does not show that you were, in reality, in possession of the invention, i.e., you did not have knowledge of all the elements required of the claims. (This is close to but distinct from the enablement requirement. Again, there is not a “bright line” test.)

An additional basis is that the issued claims are fatally indefinite.The issued patent can be challenged for reasons other than prior art patents and publications. Examples could be your prior “public” use (more than 1 year before filing the original application) or lack of enablement.

Standards For Success

A petition must show that it is more likely than not that at least one claim is unpatentable.  You must adequately rebut the claimed justifications.   This “more likely than not that there is at least one claim that is unpatentable” standard is considered to be a higher standard than the prior standard of “a reasonably likelihood of success”.

Note that the petitioner must meet two thresholds, i.e., first, demonstrate that the grounds stated in the petition has merit and second, provide evidence that the claims should, in fact, be cancelled.


A third party, e.g., a competitor, files a petition in the USPTO to initiate the proceeding.  The petition must be filed within 9 months of the issuance of your patent.

You (the patentee) will be provided a copy of any filed petition.   You will have two months to respond. The USPTO will have 3 months to evaluate the petition. The US Patent Trial and Appeals Board (PTAB) will have 12 months to decide whether one or more of the challenged claims are to be cancelled.  During the pendency of the proceeding, you will be effectively barred from bringing any infringement action.

The examiner plays no role in deciding the petition. Note also that the PTAB does not conduct a trial, but rather makes its decision based upon written evidence, which can include deposition testimony, i.e., sworn answers to written or oral questions.

As stated above, anyone can file a petition to challenge your patent during the 9 month window.


A competitor or other third party can initiate challenges to your patent on a broad array of issues.  This places a cloud on the validity of your patent during this 9 month window. You may want to wait 9 months before asserting your patent as a consequence of this 9 month window.

©David McEwing 2018

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