# MPEP § 1403: Diligence in Filing > Federal · Agency guidance · In force URL: https://www.frixlaw.com/law-library/statutes/MPEP_S1403 ## Section - **Citation:** MPEP § 1403 - **Heading:** Diligence in Filing - **Jurisdiction:** Federal - **Kind:** Agency guidance - **Status:** In force - **Text as of:** August 14, 2026 - **Source:** Compiled text - **Location:** USPTO MPEP / Chapter 1400 - Correction of Patents / MPEP § 1403 ## Text When a reissue application is filed within 2 years from the date of the original patent, a rejection on the grounds of lack of diligence or delay in filing the reissue should not normally be made. Ex parte Lafferty, 190 USPQ 202 (Bd. App. 1975); but see Rohm & Haas Co. v. Roberts Chemical Inc., 142 F. Supp. 499, 110 USPQ 93 (S.W. Va. 1956), rev’d on other grounds, 245 F.2d 693, 113 USPQ 423 (4th Cir. 1957). 35 U.S.C. 251 Reissue of defective patents ***** (d) REISSUE PATENT ENLARGING SCOPE OF CLAIMS.—No reissued patent shall be granted enlarging the scope of the claims of the original patent unless applied for within two years from the grant of the original patent. 35 U.S.C. 251(d) corresponds to the provisions of pre-AIA 35 U.S.C. 251 , fourth paragraph. Where any broadening reissue application is filed within two years from the date of the original patent, 35 U.S.C. 251 presumes diligence, and the examiner should not inquire why applicant failed to file the reissue application earlier within the two year period. See MPEP § 1412.03 for broadening reissue practice. See also In re Graff, 111 F.3d 874, 42 USPQ2d 1471 (Fed. Cir. 1997); In re Bennett, 766 F.2d 524, 528, 226 USPQ 413, 416 (Fed. Cir. 1985); In re Fotland, 779 F.2d 31, 228 USPQ 193 (Fed. Cir. 1985). A reissue application that is filed on the 2-year anniversary date of the patent grant is considered as being filed within 2 years. See Switzer v. Sockman, 333 F.2d 935, 142 USPQ 226 (CCPA 1964) (a similar rule in interferences). A reissue application can be granted a filing date without an oath or declaration, or without the basic filing fee, search fee, or examination fee being present. See 37 CFR 1.53(f) . Applicant will be given a period of time to provide the missing parts and to pay the surcharge under 37 CFR 1.16(f) . While examiners should not make rejections based on lack of diligence (which does not include rejections under 35 U.S.C. 251 for a broadening reissue that is impermissibly filed outside of the two year time period set in 35 U.S.C examination fee being present. See 37 CFR 1.53(f) . Applicant will be given a period of time to provide the missing parts and to pay the surcharge under 37 CFR 1.16(f) . While examiners should not make rejections based on lack of diligence (which does not include rejections under 35 U.S.C. 251 for a broadening reissue that is impermissibly filed outside of the two year time period set in 35 U.S.C. 251 ), courts have looked to see if a reissue applicant was diligent in correcting the error(s) in the patent. At least one recent decision from the U.S. Court of Appeals for the Federal Circuit discussed a diligence requirement for filing reissue applications, even narrowing reissues. See In re Rosuvastatin Calcium Patent Litigation, 703 F.3d 511, 526, 105 USPQ2d 1437, 1447 (Fed. Cir. 2012). In this case, the majority found the reissue applicant diligent, but the dissent (J. Mayer) believed that the patentee was not diligent in filing the narrowing reissue application because the applicant was aware of an invalidating reference for over six years and had received a rejection in a counterpart foreign application based on the same reference over two years prior to filing the reissue application. See 703 F.3d at 537-38, 105 USPQ2d at 1455-56. [top] ## Nearby sections - [MPEP § 1400.01 Introduction](https://www.frixlaw.com/law-library/statutes/MPEP_S1400.01.md) - [MPEP § 1401 Reissue](https://www.frixlaw.com/law-library/statutes/MPEP_S1401.md) - [MPEP § 1402 Grounds for Filing](https://www.frixlaw.com/law-library/statutes/MPEP_S1402.md) - [MPEP § 1403 Diligence in Filing](https://www.frixlaw.com/law-library/statutes/MPEP_S1403.md) - [MPEP § 1404 Submission of Papers Where Reissue Patent Is in Litigation](https://www.frixlaw.com/law-library/statutes/MPEP_S1404.md) - [MPEP § 1405 Reissue and Patent Term](https://www.frixlaw.com/law-library/statutes/MPEP_S1405.md) - [MPEP § 1406 Citation and Consideration of References Cited in Original Patent](https://www.frixlaw.com/law-library/statutes/MPEP_S1406.md) - [MPEP § 1410 Content of Reissue Application](https://www.frixlaw.com/law-library/statutes/MPEP_S1410.md) - [MPEP § 1410.01 Reissue Applicant and Inventor's Oath or Declaration](https://www.frixlaw.com/law-library/statutes/MPEP_S1410.01.md) - [MPEP § 1410.02 Assignee Consent to the Reissue](https://www.frixlaw.com/law-library/statutes/MPEP_S1410.02.md) - [MPEP § 1411 Form of Specification](https://www.frixlaw.com/law-library/statutes/MPEP_S1411.md) - [MPEP § 1411.01 Certificate of Correction or Disclaimer in Original Patent](https://www.frixlaw.com/law-library/statutes/MPEP_S1411.01.md) - [MPEP § 1411.02 New Matter](https://www.frixlaw.com/law-library/statutes/MPEP_S1411.02.md) - [MPEP § 1412 Content of Claims](https://www.frixlaw.com/law-library/statutes/MPEP_S1412.md) --- Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/MPEP_S1403. Check the current official text before relying on it. Not legal advice.