Third Party Observations in the U.S.

In the United States, third‑party observations offer a means for external parties to contribute to the examination of patent applications, sharing potentially relevant prior art to influence patentability. In practice, these observations allow outside parties to submit published documents to the USPTO that may affect whether an application should be granted, thereby introducing an additional quality‑control mechanism into the examination process. This raises several important questions regarding timing, content, and strategic use.

Timing

Authorized under 35 U.S.C. § 122(e), third‑party submissions must be filed within strict statutory windows. A submission is valid only if filed before the earlier of:

• The date a notice of allowance is issued; or
• The later of (i) six months after publication or (ii) the date of the examiner’s first rejection.

Even a one‑day delay results in exclusion from the record. These requirements underscore that timing is a central consideration in the effective use of third‑party observations.

Content

Submissions may only contain printed publications relevant to patentability. Each item must be accompanied by a concise statement of relevance, a compliance certification, and the required fee. These materials are strictly pointers to potential prior art, not arguments about patentability. This limitation distinguishes them from protests under 37 CFR  § 1.291, which do allow arguments and broader information.

Compliance is essential: submissions that fail to meet formatting, fee, or procedural standards are discarded without examiner review. For small entities, or those submitting three or fewer documents, a fee exemption may apply, provided that all formal statements are correctly included. Third parties eligible to submit observations include individuals, companies, or non‑practitioner filers; however, the law explicitly prohibits filing third‑party observations against one’s own applications. The filer must identify themselves and sign, though the true party in interest may remain undisclosed.

Strategic Use

The purpose of the mechanism is to improve patent quality by providing examiners with additional prior art, including non‑patent literature that might otherwise be overlooked. From a strategic perspective, the tool offers businesses both opportunities and dilemmas. Early submission can efficiently flag prior art references but may reveal competitive interests. Waiting, on the other hand, may preserve confidentiality but can instead shift challenges into costlier litigation or post‑grant review.

In comparison with third‑party observations available before the European Patent Office, the U.S. framework is deliberately narrower and more limited in scope. While both systems allow external parties to submit prior art during examination, the EPO permits more detailed argumentation and reasoning alongside references, giving examiners broader context in evaluating relevance. The U.S. approach, by contrast, confines submissions strictly to documents with brief relevance statements, avoiding argumentative input.

As a result, filings before the EPO can exert greater substantive influence on the examination record, whereas in the U.S. the mechanism remains comparatively modest. It is procedurally straightforward and accessible, but also lacks the depth of engagement possible under the European procedure, where no fee is charged for third-party observations and parties can provide more detailed reasoning alongside references. 

For businesses, the dilemma is strategic: is it better to submit observations early, risking revealing your hand, or wait to challenge via litigation or re-examination? The U.S. approach provides a valuable yet inherently limited mechanism. Its principal function is to give parties other than the applicant the opportunity to participate in the (pre-)examination process, thereby offering examiners additional perspectives and information at an early stage. By enabling early submission of prior art, third‑party observations can help prevent weak patents from being issued in the first place, thereby potentially reducing downstream disputes. 

Conclusion

Third‑party observations in U.S. patent law remain a modest but potentially helpful tool for improving patent quality during the pre‑grant phase. They require strict timing, limited content, and procedural compliance, which ensures efficiency but also constrains their potential impact compared with more expansive approaches before the EPO. Nevertheless, they serve a meaningful role by allowing outside parties to participate in (pre-)examination procedure, introduce possibly overlooked prior art, and strengthen the validity of patents that are ultimately granted.