USPTOObservations & Oppositions builder
Citation of prior art in a patent file
35 U.S.C. 301; 37 CFR 1.501
A free, optionally anonymous way to put prior art, and the owner's own statements on claim scope, into the official file of an issued US patent.
At a glance
Until expiry plus 6 years
No official fee (MPEP 2205, checked 22 Sep 2026)
- Who can file
- Any person, including a representative for an unnamed principal. The patent owner uses a separate route.
- Deadline
- Any time in the period of enforceability: patent term plus 6 years (35 U.S.C. 286), longer if litigation started within it.
- Official fee
- None (MPEP 2205).
- Language
- English. Translations of non-English art should be supplied.
- Anonymous
- Yes on paper, signer included (1.501(d)). Patent Center needs an identity-verified account, so paper is the fully anonymous route.
- How it is filed
- Patent Center's 'Prior Art Submission into Patent File' function, utility patents only, or paper to Mail Stop Post Issue.
- Effect
- Becomes part of the official patent file. Nothing else happens until a reexamination is requested or ordered.
- Party status
- None. No proceeding starts, no claims are put in issue, and no examiner has to act.
What it is
Citation of prior art in a patent file, in brief
A citation under 35 U.S.C. 301 places patents and printed publications, or the patent owner's own statements on claim scope from a court or USPTO proceeding, in the file of an issued US patent. Each item needs a written explanation of its pertinence and of how it applies to at least one claim.
It is free and, on paper, fully anonymous. It starts no proceeding and obliges no examiner to act: the record waits for a reexamination request or order. Any 112 point, public use assertion, or discussion of a reference already treated in prosecution sends the whole submission back.
Grounds it can carry
- Patents and printed publications bearing on patentability of a claim35 U.S.C. 301(a)(1); 37 CFR 1.501(a)(1)
- Patent owner statements on claim scope, for claim meaning only35 U.S.C. 301(a)(2), (d); 37 CFR 1.501(a)(2)
Use it when
- The patent has issued and is within its period of enforceability.
- You want patents or printed publications on the record without a reexamination fee or any commitment.
- You want the owner's own claim-scope statements in the file, or anonymity matters and you can file on paper.
Choose another route when
- The target is still a pending application. Third-party preissuance submission
- You want the claims re-examined now. Request for ex parte reexamination
- Your case rests on 112, public use, on-sale activity or the owner's conduct.
How IPtorch builds it
From search to filing, minus the signature.
The invalidity search runs on into this filing when it ends, with no second click. Three model families take turns, so a draft is never checked by the model that wrote it.
- 1SearchClaims split into limitations, thousands of candidates screened, at least 50 references read in full.Gemini models read and check
- 2Claim mapA verbatim quotation and its location behind every limitation.Every cell checkable
- 3DraftWrites the papers in the office's format and language.Claude Opus 5.5 (Anthropic)
- 4ReviewChecks each citation against its document and builds the forms.Sol 6 (OpenAI)
- 5AdjudicateHigh strength: a third family rules on every objection.Gemini 3.1 Pro (Google)
- 6FolderUnsigned PDFs, ready for a professional to review, sign and file.Nothing is filed
What the builder does for this filing
- IPtorch starts from an invalidity search with at least 50 references read in full and cites only patents and printed publications not treated in prosecution or an earlier reexamination.
- For each item it quotes at least one claim broken into limitations and shows, with pinpointed quotations, where the item teaches each limitation.
- Each item closes with one sentence on how it bears on the patentability of that claim; nothing asks for or argues a reexamination.
- On the anonymous route it removes every identifier of the submitter, PDF metadata included.
In the folder
- Submission under 37 CFR 1.501Cover sheet, citations, pertinence and manner of applying for each item
- Document list (PTO/SB/42 layout)Patent Center data sheet or paper list
- Owner claim-scope statementsForum, papers and pages, or a 'Not Applicable' paper
- Copies of every cited documentA cover sheet identifying the patent on each copy
- Labelled machine translationsBeside the original text, the patent identified on each
- Certificate of serviceOn the patent owner at the 1.33(c) address, last page
- Filing sheetInternal: route, no fee, anonymity scrub including PDF metadata
Builder strength
You choose how hard it is checked.
You pay for the tokens the sessions use, at the models' list prices plus a 30% fee, not for the time allowed. How pricing works
Low
- Opus 5.5 drafts the submission
- Sol 6 builds and checks the final forms
Medium
- Opus 5.5 drafts the submission
- Sol 6 reviews and rebuilds the content
- Opus 5.5 builds the filing folder
- Sol 6 checks the form
High
- Opus 5.5 drafts the submission
- Sol 6 runs a deep prior-art search
- Opus 5.5 rebuilds the submission against the evidence
- Sol 6 attacks it as an adversarial examiner
- Gemini 3.1 Pro adjudicates the objections
- Opus 5.5 applies the fixes and builds the filing folder
- Scripted checks of the filing folder
- Sol 6 audits the whole folder
- Convergence gate
If the gate fails, one repair round: opus 5.5 repairs what the gate found, sol 6 audits the repair, convergence gate, again.
What stays with you
You review, sign and file.
- Choose the route: Patent Center with an identity-verified account, or paper to Mail Stop Post Issue for anonymity.
- On the named route, sign with your own S-signature.
- Serve the full copy on the owner at the 1.33(c) address and sign the certificate.
- Press Submit in Patent Center, or post or hand-deliver the package with nothing identifying you.
Where these go wrong
What the builder guards against.
- Any 112 point, public use assertion or comment on the owner's conduct sends the whole submission back.
- Discussing a reference the examiner already handled in prosecution gets the submission returned, as in the Bond Arms return.
Start with the evidence.
Upload the patent or enter its number. The invalidity search charts every claim, and the builder takes it from there.
Start an invalidity searchFacts checked against the office's rules on 22 September 2026. IPtorch is not a law firm and this page is not legal advice. The builder's output is unsigned work product for a registered professional to review, sign and file; nothing is filed and no fee is paid for you. Confirm current requirements, fees and deadlines with the receiving office.