Under a proposed rule published July 22, any third party requesting reexamination would be required to disclose all real parties in interest to the agency — ending anonymity as to the United States Patent and Trademark Office (the Office), although a requester could still request confidential treatment of that information as to the patent owner and the public. The Office’s stated goals are to enforce the AIA’s estoppel provisions more effectively and to deter fraud. Comments are due Aug. 21.

Background and the Estoppel Problem

Anonymity has been a feature of ex parte reexamination since Congress created the procedure in 1980, permitting “any person” to seek reexamination of an issued patent based on prior art. 35 U.S.C. § 302. Current rules facilitate anonymous submissions further: a third party may submit a prior art citation or written statement under 37 C.F.R. § 1.501(d) without identifying itself, and under 35 U.S.C. § 301(e), it may request that its identity be excluded from the patent file and kept confidential from the public — though not from the Office. Congress included that confidentiality protection to ensure competitors would not be deterred from bringing relevant prior art to the Office’s attention. H.R. Rep. No. 96-1307, at 6 (1980), as reprinted in 1980 U.S.C.C.A.N. 6460, 6465. As a practical matter, a requester can achieve anonymity even as to the Office by retaining a registered patent practitioner to file the reexamination request on its behalf. MPEP 2214, subsection I.

This anonymity-friendly regime operated without significant friction until the Leahy-Smith America Invents Act (AIA), enacted in 2011 and effective in 2012, introduced a new estoppel scheme. Under 35 U.S.C. §§ 315(e)(1) and 325(e)(1), once a petitioner in an inter partes review (IPR) or post-grant review (PGR) — or its real party in interest or privy — obtains a final written decision, it is estopped from requesting or maintaining a proceeding before the Office on any ground it raised or reasonably could have raised in that IPR or PGR. Senator Kyl, one of the AIA’s principal sponsors, recognized during floor debate that enforcing this estoppel bar in the ex parte reexamination context depends on the Office actually knowing who is behind a given request. 157 Cong. Rec. S1376 (daily ed. Mar. 8, 2011) (statement of Sen. Kyl).

This is not the Office’s first attempt to address this issue. In January 2012, it proposed two new requirements for ex parte reexamination requests: an estoppel certification and a separate statement identifying all real parties in interest. (Changes To Implement Miscellaneous Post Patent Provisions of the Leahy-Smith America Invents Act, 77 Fed. Reg. 442 (Jan. 5, 2012)). When the Office finalized that rule in August 2012, only the certification requirement survived — now codified at 37 C.F.R. § 1.510(b)(6). (Changes To Implement Miscellaneous Post Patent Provisions of the Leahy-Smith America Invents Act, 77 Fed. Reg. 46,615 (Aug. 6, 2012)). The RPI disclosure requirement was dropped after commenters warned it would chill reexamination filings and raised doubts about the Office’s ability to safeguard confidential information.

More than a decade later, the Office has concluded that certification alone is no longer sufficient. Requesters (or their practitioners) are already required under § 1.510(b)(6) to certify that estoppel does not bar their request, and 37 C.F.R. § 11.18(b) separately requires that filings be truthful, made for a proper purpose, and legally and evidentially supported. Yet the Office now maintains that these safeguards, standing alone, cannot effectively police estoppel compliance — particularly given how fact-intensive RPI determinations can be. See Applications in Internet Time, LLC v. RPX Corp., 897 F.3d 1336 (Fed. Cir. 2018). Sole reliance on a requester’s self-certification, in the Office’s view, risks reexaminations being instituted that should have been barred — wasting agency resources and prejudicing patent owners.

The Proposed Rule

The proposed rule makes two changes to 37 C.F.R. pt. 1. The first is a clarifying revision: amended § 1.501(d) would make clear that anonymity is available only for papers filed “under this section” — that is, prior art citations and written statements. That distinction separates such filings from full reexamination requests under § 1.510, which would now be subject to the new RPI disclosure requirement.

The more significant change is a new § 1.510(b)(7), which would require every third-party ex parte reexamination request to include a standalone statement identifying all real parties in interest — not only the named requester, but any other entity sufficiently connected to the request to qualify as an RPI. Requesters would submit that statement electronically, in a format the Office intends to publish on its website. Notably, a requester may still request that the statement be excluded from the public patent and reexamination files under 37 C.F.R. § 1.11(d) — so the information reaches the Office, though not the public.

Patent owners filing their own reexamination requests would be exempt from this new requirement, which reaches only third parties. Because RPI status remains a fact-specific, case-by-case determination, the Office is directing parties to the same body of guidance already used for the § 1.510(b)(6) certification: Federal Circuit case law, PTAB precedential and informative decisions, and the USPTO’s Consolidated Trial Practice Guide § I(D)(1) (Oct. 2025). On the confidentiality front, the Office states that it will implement “robust data security measures” to protect RPI statements and will take reasonable steps to avoid disclosing that information in reexamination decisions.

Why Now: The Office’s Rationale

Several developments have prompted the Office to revisit a question it set aside in 2012. The USPTO reports that it is now receiving a “significant number” of ex parte reexamination requests directed to patents already challenged in IPR or PGR proceedings — raising concern that estopped parties are using anonymity to circumvent the AIA’s preclusion rules. The Office also points to a consistency rationale: because IPR petitioners must already identify all RPIs under 35 U.S.C. § 312(a)(2), imposing the same requirement in reexamination would align the two proceedings.

The proposal also dovetails with a separate pending PTAB rulemaking. In October 2025, the Office proposed a new 37 C.F.R. § 42.108(e)(5) (Revision to Rules of Practice Before the Patent Trial and Appeal Board, 90 Fed. Reg. 48,335, 48,341 (Oct. 17, 2025)) that would preclude the institution of an IPR on a claim found patentable in a prior ex parte reexamination requested by someone other than the patent owner or its RPI/privy. A public commenter on that proposal flagged that anonymous ex parte reexamination requests could undercut the preclusion provision — since the Office would have no way to confirm whether the reexamination requester was truly independent of the later IPR petitioner. RPI identification in the reexamination context closes that gap.

Finally, the Office cites a fraud-and-enforcement rationale. Access to RPI information would allow the Office to act more efficiently when it encounters apparent false certifications, misrepresentations, or unauthorized practice — the same circumstances that currently prompt the Office to issue show-cause orders.

Key Dates and Comment Procedure

Comments are due by Aug. 21. Notably, the Office was not required to solicit public input at all — it takes the position that this is a rule of agency practice or procedure exempt from notice-and-comment under 5 U.S.C. § 553(b)(A) — but has elected to seek feedback nonetheless.

• Submit comments: Federal eRulemaking Portal at regulations.gov; search docket number PTO-P-2025-0545, then select “Comment.” Attachments accepted in PDF or Word format.
• Contacts: Steven Fulk, Legal Advisor (571-270-0072); Nicole Haines, Senior Legal Advisor (571-272-7717), Office of Patent Legal Administration.
• Status: Proposed rule only — not yet final. The Office may modify or withdraw the proposal based on comments received.

Practical Implications

For prospective third-party requesters, the most significant consequence is the end of anonymity as to the Office. Filing through a registered practitioner would no longer shield a requester’s identity from the Office — it would shield that identity only from the patent owner and the public, and only upon request. Companies that have relied on anonymous ex parte reexamination as a post-IPR strategy, or as a means of challenging patents without revealing competitive interest, will need to reassess that approach. Before filing, requesters should conduct a rigorous pre-filing RPI analysis — weighing funding relationships, control, benefit, and the other fact-specific factors that federal circuit case law considers — since an incomplete or inaccurate disclosure could implicate 37 C.F.R. § 11.18 and expose the requester to fraud, misrepresentation, or disciplinary consequences. Parties already subject to AIA estoppel, or whose RPI or privy status is debatable, face the greatest exposure: once this rule takes effect, the Office will have the information it needs to identify and enforce estoppel bars.

For patent owners, the benefit is more indirect. Because a requester may request confidential treatment of the RPI statement, patent owners may not gain access to that information — the disclosure is made to the Office, not necessarily to the patent owner. The more immediate beneficiary is the Office, which would gain the ability to independently evaluate whether AIA estoppel bars a given request, reducing the risk that reexamination proceeds where it should be statutorily barred. If this proposal and the pending 37 C.F.R. § 42.108(e)(5) rule are both finalized, the combined regime would mean that a reexamination finding of patentability could preclude a later IPR on that claim (subject to the RPI/privy limitation), with the Office — rather than necessarily the patent owner — holding the information needed to enforce that preclusion. Patent owners who have faced anonymous reexamination challenges, or who are engaged in ongoing estoppel disputes, may wish to file comments supporting the proposal before the August 21 deadline.

For all stakeholders, the comment period presents a meaningful opportunity. The Office rejected this same proposal in 2012 based on commenter concerns regarding chilling effects and confidentiality safeguards — suggesting that well-supported comments can influence the outcome. Comments that thoughtfully address the scope of RPI determinations, the adequacy of the proposed data security measures, the potential impact on reexamination filing volume, and the interaction between this rule and the broader AIA estoppel framework are likely to carry particular weight. The Office has also signaled its intent to use RPI information proactively in fraud and misrepresentation investigations, raising the stakes for accurate and complete disclosure.

If you have questions about how this proposed rule may affect your patent enforcement or challenge strategies, or if you would like assistance preparing comments for submission to the USPTO, please contact a member of our Intellectual Property Litigation group.

Source: Requirement To Identify All Real Parties in Interest to a Third Party Request for an Ex Parte Reexamination, 91 Fed. Reg. 46,038 (July 22, 2026), Docket No. PTO-P-2025-0545, RIN 0651-AD94. Signed by John A. Squires, Under Secretary of Commerce for Intellectual Property and Director of the United States Patent and Trademark Office.