USPTO Now Requires an Explanation for Unintentional-Delay Petitions Filed More Than One Year Late

The U.S. Patent and Trademark Office has shortened from two years to one the period after which an applicant or patentee seeking relief for unintentional delay must explain the delay rather than merely certify it. The final rule, published in the Federal Register on 24 June 2026 under Docket No. PTO-P-2025-0413, took effect on 13 August 2026 and applies to any petition filed after that date. It also moves the trigger for the higher petition fee in 37 CFR § 1.17(m)(1) to the same one-year mark.

The change reaches four families of petition: revival of an abandoned application under § 1.137, acceptance of a delayed maintenance fee under § 1.378, acceptance of a delayed foreign-priority or domestic-benefit claim under § 1.55(e) and § 1.78(c) and (e), and excusal of a missed time limit in an international design application under § 1.1051. Each rule already required a statement that the entire delay was unintentional and allowed the Director to “require additional information where there is a question whether the delay was unintentional.” The new rule fixes when that question is taken to arise. More rulemaking coverage is on the USPTO & Prosecution hub.

What changed, and from what?

The Office’s practice since a 2 March 2020 clarification notice (85 FR 12222) was to require additional information when a petition was filed more than two years after the application became abandoned, the patent expired or the priority or benefit claim was due. The 2026 rule states that the Office “has decided to shorten the two-year period for requiring additional information to one year.” Its reasoning is that “[i]f the period of delay is more than one year, there is a sufficient concern that the entire delay may not be unintentional and thus warrant a requirement for an additional explanation of the circumstances surrounding the delay.”

Petitioners past the one-year mark “must provide an additional explanation of the circumstances surrounding the delay that establishes that the entire delay was unintentional.” The notice says this is “in addition to” the existing statement of unintentional delay, and that the Manual of Patent Examining Procedure will be updated “in due course.” Until then, MPEP § 711.03(c), which the notice cites as generally applicable to every unintentional-delay petition, remains the reference point for what the standard requires.

Does the one-year line limit when the Office can ask?

No. The rule states that nothing in it “should be construed as an indication that the USPTO will only require additional information” for petitions filed more than one year late, and that “[s]eparate and apart from the one-year period in this notice, the USPTO may require additional information whenever there is a question as to whether the delay was unintentional.” The notice also recalls that the Office usually accepts the bare statement because the applicant or patentee is obligated under 37 CFR § 11.18 to inquire into the facts, and it cites In re Rembrandt Technologies (Fed. Cir. 2018), where patents were held unenforceable after an inaccurate statement that a delay was unintentional.

How does the fee change work?

The rule amends § 1.17(m)(1) so that its fee applies “when the petition is filed more than one year after the date when the required action was due,” replacing the former two-year condition. The notice says the increased evidentiary requirements raise the cost of reviewing late petitions and that the earlier fee trigger “will further encourage applicants to file their petitions in a timely manner.” The amounts in the table are unchanged: $600 for a micro entity, $1,200 for a small entity and $3,000 for other applicants. The Office states that “[t]he fee rates in 37 CFR 1.17(m) will remain the same.”

The amended paragraph lists the petitions it covers by rule: § 1.55(e) priority claims and § 1.78(c) or (e) benefit claims filed more than one year after they were due; § 1.137 revivals filed more than one year after abandonment, including revival of a terminated reexamination; § 1.378 maintenance-fee petitions filed more than one year after expiration; and § 1.1051 petitions filed more than one year after abandonment of an international design application.

Why no notice and comment?

The Office classified the rule as one of agency practice and procedure, or an interpretive rule, exempt from notice-and-comment rulemaking under 5 U.S.C. § 553(b)(A). It says the change “does not change the substantive criteria of patentability” and cites Cooper Technologies v. Dudas (Fed. Cir. 2008) and In re Chestek (Fed. Cir. 2024) for the proposition that procedural rules are exempt. The notice was signed by John A. Squires, Under Secretary of Commerce for Intellectual Property and Director of the USPTO.

What changes for practitioners?

The practical effect is that docketing errors discovered in the second year after a lapse now carry both a higher fee and an evidentiary burden. Practitioners may consider treating the first anniversary of an abandonment, expiration or missed claim as a hard internal deadline for filing a grantable petition, since the notice ties the Office’s concern to the length of the delay itself. Where a lapse is found after a year, the explanation must account for the entire period from the missed date to the petition, not only for the original slip, because an applicant “cannot meet the ‘unintentional delay’ standard . . . if the entire delay is not unintentional.”

The notice frames the rule as protecting third parties who may have relied on an application’s abandoned status or a patent’s expiration. Competitors reviewing a lapsed patent for freedom to operate may read the one-year line the same way: a petition filed inside the year faces the ordinary certification, while one filed later must be supported on the record and will show up in the file wrapper. Plain-English guides to patent procedure are collected on the Explainers hub.