Duty of Disclosure

Failure to disclose relevant information to the United States Patent and Trademark Office (USPTO) can result in a patent becoming invalid and unenforceable.

Everyone involved in the filing and prosecution of a US patent application has a duty to disclose to the USPTO all information which is relevant in assessing the patentability of the invention which is the subject of the patent application. This applies not only to the inventor(s) but also to anyone else who is involved with the patent application, for example, patent owners and patent attorneys.

Information is considered to be “relevant” if the US examiner is likely to need to take it into account when examining the application. That is, if it may arguably render any claim unpatentable. If there is any doubt about relevance, it is advisable to disclose the information.

In order to comply with this duty of disclosure requirement, we must send any information relating to “prior art” to the US attorney handling the application. This should be done as early in the procedure as possible. The duty to disclose is ongoing through the life of a US patent application so if relevant prior art is identified later we must also tell the USPTO about it. In rare circumstances if the prior art is very relevant this can reopen issues in examination.

As a general guide, the following categories of information should be considered:

1. patents or other published documents relating to the invention or to the technical field of the invention (these may be cited by patent examiners in other jurisdictions on related applications);
2. products or processes, either yours or someone else’s, which are similar to your invention;
3. other US patents or patent applications which you may have in the same area of technology;
4. any other information which you think may be relevant.

Of course, the date must be considered. Generally, anything made available after the effective filing date is not considered prior art. However, there are exceptions to this; in particular, US patent applications that published after the effective filing date but were filed before. A patent attorney is best-placed to help with this so we recommend sending anything that may be relevant to us for us to consider.

Also of relevance is any use, sale, offer for sale or advertisement of the invention. Any dispute about ownership of the invention or the identity of the inventor(s) is also  relevant.

Although the US is the most common jurisdiction for which duty of disclosure requirements are considered, other patent offices including those of Israel and India ask for similar information.

If you have any questions about the duty to disclose, please ask your usual Mewburn contact or email mail@mewburn.com.

This information is simplified and must not be taken as a definitive statement of the law or practice.