September 2020 Newsletter

Vol 13, Issue 2

Virtual Patent Marking Overview

By Kevin Spexarth

When a patentee manufactures or sells an article that is covered by a U.S. patent, the patentee should provide notice to the public by complying with the patent “marking” statute (35 U.S.C. § 287). While patent marking is not mandatory, not doing so can limit damages from infringement suits. For example, failure to correctly mark often precludes recovery of pre-suit damages unless actual notice of the granted patent was given to the infringer.

Traditional Patent Marking

Traditionally, patent marking involves fixing onto the article the word “patent” or abbreviation “pat.” and the number of the patent (e.g., Patent 9,876,543 or Pat. 9,876,543), for example by embossing, or applying an adhesive label or plaque to the patented article. When it is not possible to fix the patent information on the patented article itself (e.g., the patented article is very small), the information can be fixed to the packaging of the patented article.

This traditional approach has certain limitations. As patents expire, new patents grant, and/or the design of the patented article changes, the patent marking information on the patented article must be updated to include these new patents, and/or to omit patents that no longer cover the patented article. Removal of expired patents is particularly critical, as falsely marking the patented article may expose the company to liability. In addition to this upkeep, it may be burdensome to list all the patents on the patented article, depending on the size of the patented article and available physical space, and the number of patents that must be listed.

Virtual Patent Marking

To reduce the limitations associated with traditional patent marking, while still providing constructive notice to the public, the 2012 America Invents Act introduced “virtual” patent marking. Generally, virtual patent marking involves fixing onto the patented article not the patent numbers themselves, but a URL of a website that lists the patented article (e.g., by model name or number) together with the patent number(s) that covers each patented article. Accordingly, as patents expire, new patents grant, and/or the design of the patented article changes, the patentee can update the website at little or no cost and without changing the label or other marking that is fixed to the patented article.

Best Practices for Virtual Patent Marking

Compliance with the patent marking statute is achieved by fixing on the article (or packaging if necessary) the word “patent” or abbreviation “pat.” with a URL of a website (e.g., Patent:; Pat.: If space permits, a detailed statement can provide more information, e.g., This product may be covered by one or more U.S. or international patents or pending patent applications. See Pat.: for details.

There are no format or layout requirements for the website providing the virtual patent marking. However, the website must clearly associate the patent number(s) to the patented article and the website must be accessible to the public without charge or obstacle. Importantly, it is not adequate to simply list all patents that the patentee owns, or that might cover a product. Just as with the traditional approach, a member of the public inspecting the patented article should be put on notice of the specific patents that cover the patented article.

There are many ways in which to design the website to associate the patent number(s) to the patent article. Below is an example of a simple table that associates the patent number(s) to the patented article.


Patented Article

US Patent

Machine Model A


Machine Model B

US1,111,111; US2,222,222; US4,444,444

Machine Model C

US2,222,222, US3,333,333


Also note that once the virtual patent marking information is fixed to the patented article and the website is created, the website must be accurately maintained. For example, as patents expire, new patents grant, the design of the patented article changes, and/or new patented articles are developed, the website must be updated so that the website remains in compliance with the patent marking statute. Failure to update the website in a timely fashion can limit the recovery of damages and potentially lead to claims of false patent marking. A website maintenance process can be implemented to maintain the website and the process may include:

  • Designating an employee responsible for maintaining the website.
  • Implementing a patent marking review committee that will review each newly granted patent and determine which product(s) are associated with the patent.
  • Setting up a quarterly or bi-annual review meeting to review the website and determine if changes should be made (e.g., remove expired patents, add new products to the website).


Virtual patent marking can provide a superior alternative to traditional patent marking in many situations. However, virtual patent markings must be correctly implemented and accurately maintained to ensure that your company enjoys the benefits of the patent marking statute when using virtual patent markings.

Please contact your Andrus attorney if you wish to discuss how virtual patent marking may help your business and streamline your existing patent marking processes. We strongly recommend that you consult with your Andrus attorney before implementing any virtual patent marking practices to ensure that the proposed practices comply with the patent marking statute and adhere to recent legal developments.


Andrus New Offices

Andrus will be moving to the BMO Tower in downtown Milwaukee in October. Andrus is excited to be one of the newest tenants in the new building, located at 790 North Water Street in Milwaukee.

Aaron Olejniczak Selected for Inclusion in 2021 Best Lawyers

We are pleased to announce that Aaron Olejniczak has been selected by his peers as the 2021 Best Lawyers® “Lawyer of the Year” for Patent Litigation in Milwaukee! Aaron will also be highlighted in the print edition of The Best Lawyers in America© for Litigation - Intellectual Property and Litigation – Patents (