An amendment after allowance under 37 CFR 1.312 lets you request changes to a patent application after the USPTO mails the Notice of Allowance, but only if you file before paying the issue fee, the primary examiner recommends entry, and a supervisor approves it. It is not a right, and it is not a second round of prosecution. Think of it as a narrow cleanup window.
When You Can File
The window opens the day the USPTO mails your Notice of Allowance and closes when you pay the issue fee. You have three months from the mailing date to pay that fee, and the USPTO does not extend this deadline.1United States Patent and Trademark Office. 1303-Notice of Allowance Most applicants file well before the deadline so the examiner has time to look at the request.
Once the issue fee is paid, the door essentially closes. The regulation states that the amendment “must be filed before or with the payment of the issue fee.”2eCFR. 37 CFR 1.312 – Amendments After Allowance Changes after payment require a petition to withdraw the application from issue under 37 CFR 1.313, which itself demands either an unequivocal statement that one or more claims are unpatentable, a request for continued examination, or express abandonment of the application.3United States Patent and Trademark Office. Withdrawal From Issue After Payment of the Issue Fee That is a much heavier lift than a 1.312 amendment.
What the USPTO Will Actually Accept
The MPEP is blunt: Rule 1.312 “was never intended to provide a way for the continued prosecution of an application after it has been passed for issue.”4United States Patent and Trademark Office. 714-Amendments, Applicants Action To be accepted, a proposed change generally must be needed for proper disclosure or protection of the invention, and it must not require substantial additional work by the Office.
The primary examiner can approve certain categories of changes without escalating:
- Formal corrections to the specification or drawings, such as fixing typos, correcting reference numbers, or updating inventor names.
- Formal claim corrections that do not change scope, such as grammar or clarity fixes.
- Cancellation of claims you no longer want in the patent.
Anything that touches the disclosure, adds claims, or changes the scope of an existing claim must be forwarded to a supervisory patent examiner.4United States Patent and Trademark Office. 714-Amendments, Applicants Action That extra review makes scope-changing amendments significantly harder to get in, and the USPTO denies most of them in practice. If a proposed claim would require a fresh prior art search or raise a new patentability issue, expect a denial.
How to Prepare the Filing
There is no separate USPTO fee for a 1.312 amendment itself. If you add claims beyond the number already paid for, excess claims fees apply. Title the document “Amendment After Allowance Under 37 CFR 1.312” and identify the application by number, filing date, and invention title.
Mark each change using standard USPTO conventions: underline new text and bracket text being deleted. Precision matters. The MPEP allows the Office to deny an amendment that is “so worded that it cannot be entered with certain accuracy.”4United States Patent and Trademark Office. 714-Amendments, Applicants Action
Include a remarks section explaining, for each change, why it is necessary and why it was not made during regular prosecution. State affirmatively that the changes will not require additional searching or examination. This is where filings tend to succeed or fail. A bare request with no explanation is easy to deny, and a vague justification is nearly as bad. Be specific: if you are fixing a reference numeral that was transposed in a drawing description, say so and point to where the correct numeral appears elsewhere in the specification.
File the amendment through Patent Center, the USPTO’s electronic filing portal.5United States Patent and Trademark Office. Patent Center
How the Review Works
Once the Notice of Allowance mails, the application is technically no longer under the primary examiner’s jurisdiction. The examiner reviews 1.312 amendments as a courtesy. The regulation requires two levels of approval: the primary examiner recommends entry, and the Director, in practice a supervisory patent examiner acting under delegated authority, approves it.2eCFR. 37 CFR 1.312 – Amendments After Allowance
Purely formal corrections tend to move quickly because the examiner handles them alone. When an amendment touches claim scope or the disclosure, the supervisory review adds time and a second decision-maker who may disagree with the examiner. Reviews typically take several weeks, sometimes longer depending on the technology center’s workload. You receive a formal response either way. If the amendment is denied, the examiner provides a brief explanation, though the MPEP notes that “a detailed statement of reasons is not necessary.”4United States Patent and Trademark Office. 714-Amendments, Applicants Action
If the Amendment Is Denied
There is no formal appeal from a denied 1.312 amendment. The application proceeds to issuance with the text that existed at the time of allowance. For minor typos and clerical mistakes, that is annoying but fixable later. For substantive changes, the consequences are more serious.
Two main paths remain. You can file a Request for Continued Examination under 37 CFR 1.114, which reopens prosecution and lets you present the amendment during a full examination cycle. Current RCE fees are listed on the USPTO fee schedule and vary by entity size and whether it is your first RCE or a later one.6United States Patent and Trademark Office. USPTO Fee Schedule Alternatively, you can file a continuation application, which preserves your original priority date while letting you pursue different or broader claims.
Either option adds months or years and costs substantially more than the 1.312 amendment would have. The post-allowance window is a safety net, not a second chance at prosecution.
Fixing Errors After the Patent Issues
If the amendment window has closed and a mistake makes it into the issued patent, a certificate of correction is a narrower remedy for minor problems. Under 35 U.S.C. 255, you can request one for a clerical, typographical, or otherwise minor error made in good faith, so long as the correction does not introduce new matter or require reexamination.7Office of the Law Revision Counsel. 35 USC 255 – Certificate of Correction The filing fee is $172.8eCFR. 37 CFR 1.20 – Post-Issuance Fees When the mistake was the USPTO’s and is clearly shown in Office records, the Director can issue a certificate at no cost, after notifying the patentee.9eCFR. 37 CFR 1.322 – Certificate of Correction of Office Mistake
A certificate of correction is not a substitute for a 1.312 amendment. It cannot change claim scope or add claims. For the typo caught after issuance, though, it is far cheaper and faster than anything else available.