MPEP § 502 — Depositing Correspondence (Annotated Rules)

§502 Depositing Correspondence

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 502, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Depositing Correspondence

This section addresses Depositing Correspondence. Primary authority: 37 CFR 1.6, 37 CFR 1.53(d), and 37 CFR 1.495. Contains: 2 requirements, 2 guidance statements, 5 permissions, and 3 other statements.

Key Rules

Topic

Continued Prosecution Applications

4 rules
StatutoryPermittedAlways
[mpep-502-b9a389c843dcee596d911c12]
Petition for Filing Date After Missing Receipt Evidence
Note:
A party may petition the Director to assign a filing date if no evidence of receipt is shown for a facsimiled continued prosecution application, provided they meet certain conditions.
(f) Facsimile transmission of a patent application under § 1.53(d). In the event that the Office has no evidence of receipt of an application under § 1.53(d) (a continued prosecution application) transmitted to the Office by facsimile transmission, the party who transmitted the application under § 1.53(d) may petition the Director to accord the application under § 1.53(d) a filing date as of the date the application under § 1.53(d) is shown to have been transmitted to and received in the Office,
  • (1) Provided that the party who transmitted such application under § 1.53(d):
    • (i) Informs the Office of the previous transmission of the application under § 1.53(d) promptly after becoming aware that the Office has no evidence of receipt of the application under § 1.53(d);
    • (ii) Supplies an additional copy of the previously transmitted application under § 1.53(d); and
    • (iii) Includes a statement which attests on a personal knowledge basis or to the satisfaction of the Director to the previous transmission of the application under § 1.53(d) and is accompanied by a copy of the sending unit’s report confirming transmission of the application under § 1.53(d) or evidence that came into being after the complete transmission and within one business day of the complete transmission of the application under § 1.53(d).
  • (2) The Office may require additional evidence to determine if the application under § 1.53(d) was transmitted to and received in the Office on the date in question.
Jump to MPEP Source · 37 CFR 1.53(d)Continued Prosecution ApplicationsApplication Types and FilingPTAB Contested Case Procedures
StatutoryRecommendedAlways
[mpep-502-d544bace366bbd70a53e4f68]
Methods for Submitting Patent Applications
Note:
Patent applications can be mailed or hand-carried to the USPTO, but electronic filing is recommended when possible.

All applications (provisional and nonprovisional) may be sent to the U.S. Patent and Trademark Office by mail using the United States Postal Service (see MPEP § 501), or they may be hand-carried to the Customer Service Window in Alexandria, Virginia. However, applicants should consider filing new patent applications (as well as patent-related correspondence) via the USPTO patent electronic filing system whenever permitted. See the USPTO Online Filing webpage for additional information on the USPTO patent electronic filing system (www.uspto.gov/patents/apply). See also MPEP § 502.05. New applications cannot be transmitted by facsimile and are not entitled to the benefit of a Certificate of Transmission under 37 CFR 1.8. A request for a continued prosecution application (CPA) filed under 37 CFR 1.53(d) (available only for design applications) may be transmitted to the Office by facsimile (37 CFR 1.6(d)(3)); however, it is not entitled to the benefit of a Certificate of Transmission (see 37 CFR 1.8(a)(2)(i)(A)). See 37 CFR 1.6(d) and MPEP § 502.01.

Jump to MPEP Source · 37 CFR 1.8Continued Prosecution ApplicationsDocuments Excluded from Certificate PracticeCertificate of Mailing
StatutoryInformativeAlways
[mpep-502-6e901045ee50410dea21eb38]
Transmission of CPA by Facsimile Not Permitted
Note:
New applications and related correspondence cannot be transmitted via facsimile but must be filed electronically through the USPTO patent electronic filing system.

All applications (provisional and nonprovisional) may be sent to the U.S. Patent and Trademark Office by mail using the United States Postal Service (see MPEP § 501), or they may be hand-carried to the Customer Service Window in Alexandria, Virginia. However, applicants should consider filing new patent applications (as well as patent-related correspondence) via the USPTO patent electronic filing system whenever permitted. See the USPTO Online Filing webpage for additional information on the USPTO patent electronic filing system (www.uspto.gov/patents/apply). See also MPEP § 502.05. New applications cannot be transmitted by facsimile and are not entitled to the benefit of a Certificate of Transmission under 37 CFR 1.8. A request for a continued prosecution application (CPA) filed under 37 CFR 1.53(d) (available only for design applications) may be transmitted to the Office by facsimile (37 CFR 1.6(d)(3)); however, it is not entitled to the benefit of a Certificate of Transmission (see 37 CFR 1.8(a)(2)(i)(A)). See 37 CFR 1.6(d) and MPEP § 502.01.

Jump to MPEP Source · 37 CFR 1.8Continued Prosecution ApplicationsDocuments Excluded from Certificate PracticeCertificate of Mailing
StatutoryPermittedAlways
[mpep-502-e2f3344dfd8e994eda0c4437]
Facsimile for Design CPA Not Entitled to Certificate of Transmission
Note:
A request for a continued prosecution application (CPA) for design applications can be transmitted by facsimile but does not qualify for the benefit of a Certificate of Transmission.

All applications (provisional and nonprovisional) may be sent to the U.S. Patent and Trademark Office by mail using the United States Postal Service (see MPEP § 501), or they may be hand-carried to the Customer Service Window in Alexandria, Virginia. However, applicants should consider filing new patent applications (as well as patent-related correspondence) via the USPTO patent electronic filing system whenever permitted. See the USPTO Online Filing webpage for additional information on the USPTO patent electronic filing system (www.uspto.gov/patents/apply). See also MPEP § 502.05. New applications cannot be transmitted by facsimile and are not entitled to the benefit of a Certificate of Transmission under 37 CFR 1.8. A request for a continued prosecution application (CPA) filed under 37 CFR 1.53(d) (available only for design applications) may be transmitted to the Office by facsimile (37 CFR 1.6(d)(3)); however, it is not entitled to the benefit of a Certificate of Transmission (see 37 CFR 1.8(a)(2)(i)(A)). See 37 CFR 1.6(d) and MPEP § 502.01.

Jump to MPEP Source · 37 CFR 1.8Continued Prosecution ApplicationsDocuments Excluded from Certificate PracticeCertificate of Mailing
Topic

Grounds for Reissue

4 rules
StatutoryRequiredAlways
[mpep-502-f446d42f0a6ae410c7163fbf]
Identification of Application Number and Filing Date Required for Correspondence
Note:
All correspondence related to a national patent application must include the application number, serial number, and filing date as required by 37 CFR 1.6.

All correspondence related to a national patent application already filed with the U.S. Patent and Trademark Office must include the identification of the application number or the serial number and the filing date assigned to the application by the Office. Any correspondence not containing the proper identification set forth in 37 CFR 1.5(a) will be returned to the sender by the Office of Patent Application Processing (OPAP). Each paper should be inspected to assure that the papers being returned contain an “Office Date” stamp indicating the date of receipt. If there is a minor obvious error in the identification of the application such that the Office readily recognizes both the existence of the error and the appropriate correction, the error can be corrected by the Office. The Office often experiences difficulty in matching incoming papers with the application file to which they pertain because insufficient or erroneous information is given. This applies especially to amendments, powers of attorney, changes of address, status letters, petitions for extension of time, and other petitions.

Jump to MPEP Source · 37 CFR 1.5(a)Grounds for ReissueAccess to Patent Application Files (MPEP 101-106)Reissue Patent Practice
StatutoryInformativeAlways
[mpep-502-6789503031824f4b5484d1cd]
Proper Application Identification Required for Correspondence
Note:
All correspondence must include the correct application number, serial number, and filing date to be processed by OPAP.

All correspondence related to a national patent application already filed with the U.S. Patent and Trademark Office must include the identification of the application number or the serial number and the filing date assigned to the application by the Office. Any correspondence not containing the proper identification set forth in 37 CFR 1.5(a) will be returned to the sender by the Office of Patent Application Processing (OPAP). Each paper should be inspected to assure that the papers being returned contain an “Office Date” stamp indicating the date of receipt. If there is a minor obvious error in the identification of the application such that the Office readily recognizes both the existence of the error and the appropriate correction, the error can be corrected by the Office. The Office often experiences difficulty in matching incoming papers with the application file to which they pertain because insufficient or erroneous information is given. This applies especially to amendments, powers of attorney, changes of address, status letters, petitions for extension of time, and other petitions.

Jump to MPEP Source · 37 CFR 1.5(a)Grounds for ReissueAccess to Patent Application Files (MPEP 101-106)Reissue Patent Practice
StatutoryRecommendedAlways
[mpep-502-72cafd1366baa3a806fcff4a]
Office Date Stamp Requirement for Returned Papers
Note:
Each paper returned by the Office must contain an 'Office Date' stamp indicating its receipt date.

All correspondence related to a national patent application already filed with the U.S. Patent and Trademark Office must include the identification of the application number or the serial number and the filing date assigned to the application by the Office. Any correspondence not containing the proper identification set forth in 37 CFR 1.5(a) will be returned to the sender by the Office of Patent Application Processing (OPAP). Each paper should be inspected to assure that the papers being returned contain an “Office Date” stamp indicating the date of receipt. If there is a minor obvious error in the identification of the application such that the Office readily recognizes both the existence of the error and the appropriate correction, the error can be corrected by the Office. The Office often experiences difficulty in matching incoming papers with the application file to which they pertain because insufficient or erroneous information is given. This applies especially to amendments, powers of attorney, changes of address, status letters, petitions for extension of time, and other petitions.

Jump to MPEP Source · 37 CFR 1.5(a)Grounds for ReissueAccess to Patent Application Files (MPEP 101-106)Reissue Patent Practice
StatutoryPermittedAlways
[mpep-502-64837dc9e29bb0bfbcca1df5]
Minor Errors in Application Identification Can Be Corrected by Office
Note:
If there is a minor obvious error in the identification of an application, the Office can correct it if they readily recognize both the error and the appropriate correction.

All correspondence related to a national patent application already filed with the U.S. Patent and Trademark Office must include the identification of the application number or the serial number and the filing date assigned to the application by the Office. Any correspondence not containing the proper identification set forth in 37 CFR 1.5(a) will be returned to the sender by the Office of Patent Application Processing (OPAP). Each paper should be inspected to assure that the papers being returned contain an “Office Date” stamp indicating the date of receipt. If there is a minor obvious error in the identification of the application such that the Office readily recognizes both the existence of the error and the appropriate correction, the error can be corrected by the Office. The Office often experiences difficulty in matching incoming papers with the application file to which they pertain because insufficient or erroneous information is given. This applies especially to amendments, powers of attorney, changes of address, status letters, petitions for extension of time, and other petitions.

Jump to MPEP Source · 37 CFR 1.5(a)Grounds for ReissueReissue Patent PracticeObviousness
Topic

Identifying the Application

3 rules
StatutoryRecommendedAlways
[mpep-502-60597a0ce036b87d26d51697]
Application Number Must Be Identified Before Filing Correspondence
Note:
All correspondence regarding an application must include the assigned application number before filing, and must identify the application details if previously filed.

(a) No correspondence relating to an application should be filed prior to receipt of the assigned application number (i.e., U.S. application number, international application number, or international registration number as appropriate). When correspondence directed to the Patent and Trademark Office concerns a previously filed application for a patent, it must identify on the top page in a conspicuous location, the application number (consisting of the series code and the serial number; e.g., 07/123,456), or the serial number and filing date assigned to that application by the Patent and Trademark Office, or the international application number of the international application, or the international registration number of an international design application. Any correspondence not containing such identification will be returned to the sender where a return address is available. The returned correspondence will be accompanied with a cover letter which will indicate to the sender that if the returned correspondence is resubmitted to the Patent and Trademark Office within two weeks of the mail date on the cover letter, the original date of receipt of the correspondence will be considered by the Patent and Trademark Office as the date of receipt of the correspondence. Applicants may use either the Certificate of Mailing or Transmission procedure under § 1.8 or the Priority Mail Express ® procedure under § 1.10 for resubmissions of returned correspondence if they desire to have the benefit of the date of deposit in the United States Postal Service. If the returned correspondence is not resubmitted within the two-week period, the date of receipt of the resubmission will be considered to be the date of receipt of the correspondence. The two-week period to resubmit the returned correspondence will not be extended. In addition to the application number, all correspondence directed to the Patent and Trademark Office concerning applications for patent should also state the name of the first listed inventor, the title of the invention, the date of filing the same, and if known, the group art unit or other unit within the Patent and Trademark Office responsible for considering the correspondence and the name of the examiner or other person to which it has been assigned.

Jump to MPEP Source · 37 CFR 1.8Identifying the ApplicationCorrespondence AddressCorrespondence with the Office
StatutoryRequiredAlways
[mpep-502-1737d7be7cc686b6471eed10]
Identification of Previously Filed Patent Application
Note:
Correspondence concerning a previously filed patent application must include the application number, serial number and filing date, or international registration number. Failure to do so will result in return of the correspondence.

(a) No correspondence relating to an application should be filed prior to receipt of the assigned application number (i.e., U.S. application number, international application number, or international registration number as appropriate). When correspondence directed to the Patent and Trademark Office concerns a previously filed application for a patent, it must identify on the top page in a conspicuous location, the application number (consisting of the series code and the serial number; e.g., 07/123,456), or the serial number and filing date assigned to that application by the Patent and Trademark Office, or the international application number of the international application, or the international registration number of an international design application. Any correspondence not containing such identification will be returned to the sender where a return address is available. The returned correspondence will be accompanied with a cover letter which will indicate to the sender that if the returned correspondence is resubmitted to the Patent and Trademark Office within two weeks of the mail date on the cover letter, the original date of receipt of the correspondence will be considered by the Patent and Trademark Office as the date of receipt of the correspondence. Applicants may use either the Certificate of Mailing or Transmission procedure under § 1.8 or the Priority Mail Express ® procedure under § 1.10 for resubmissions of returned correspondence if they desire to have the benefit of the date of deposit in the United States Postal Service. If the returned correspondence is not resubmitted within the two-week period, the date of receipt of the resubmission will be considered to be the date of receipt of the correspondence. The two-week period to resubmit the returned correspondence will not be extended. In addition to the application number, all correspondence directed to the Patent and Trademark Office concerning applications for patent should also state the name of the first listed inventor, the title of the invention, the date of filing the same, and if known, the group art unit or other unit within the Patent and Trademark Office responsible for considering the correspondence and the name of the examiner or other person to which it has been assigned.

Jump to MPEP Source · 37 CFR 1.8Identifying the ApplicationExpress Mail Filing DateHague Definitions
StatutoryRecommendedAlways
[mpep-502-82c579f97a9205f94988097c]
Facsimile Transmissions for Correspondence Must Include Application Identifiers
Note:
Correspondence, including authorizations to charge a deposit account, may be transmitted by facsimile but must include specific identifiers and cannot include certain types of documents.
(d) Facsimile transmission. Except in the cases enumerated below, correspondence, including authorizations to charge a deposit account, may be transmitted by facsimile. The receipt date accorded to the correspondence will be the date on which the complete transmission is received in the United States Patent and Trademark Office, unless that date is a Saturday, Sunday, or Federal holiday within the District of Columbia. See paragraph (a)(3) of this section. To facilitate proper processing, each transmission session should be limited to correspondence to be filed in a single application or other proceeding before the United States Patent and Trademark Office. The application number of a patent application, the control number of a reexamination or supplemental examination proceeding, the interference number of an interference proceeding, the trial number of a trial proceeding before the Board, or the patent number of a patent should be entered as a part of the sender's identification on a facsimile cover sheet. Facsimile transmissions are not permitted and, if submitted, will not be accorded a date of receipt in the following situations:
  • (1) [Reserved];
  • (2) Certified documents as specified in § 1.4(f);
  • (3) Correspondence that cannot receive the benefit of the certificate of mailing or transmission as specified in § 1.8(a)(2)(i)(A) through (D),(F), (I), and (K), and § 1.8(a)(2)(iii)(A), except that a continued prosecution application under § 1.53(d) may be transmitted to the Office by facsimile;
  • (4) Color drawings submitted under §§ 1.81, 1.83 through 1.85, 1.152, 1.165, 1.173, 1.437, or 1.1026;
  • (5) A request for reexamination under § 1.510 or § 1.913, or a request for supplemental examination under § 1.610;
  • (6) Correspondence to be filed in an application subject to a secrecy order under §§ 5.1 through 5.5 of this chapter and directly related to the secrecy order content of the application;
  • (7) In contested cases and trials before the Patent Trial and Appeal Board, except as the Board may expressly authorize.
Jump to MPEP Source · 37 CFR 1.6Identifying the ApplicationAppeals in ReexaminationCorrespondence with the Office
Topic

Title Format Requirements

2 rules
StatutoryInformativeAlways
[mpep-502-7c408b72975883a27b0956a9]
Resubmission Within Two Weeks Required
Note:
If returned correspondence is resubmitted to the Patent and Trademark Office within two weeks of the mail date on the cover letter, the original date of receipt will be considered. Otherwise, the new submission date applies.

(a) No correspondence relating to an application should be filed prior to receipt of the assigned application number (i.e., U.S. application number, international application number, or international registration number as appropriate). When correspondence directed to the Patent and Trademark Office concerns a previously filed application for a patent, it must identify on the top page in a conspicuous location, the application number (consisting of the series code and the serial number; e.g., 07/123,456), or the serial number and filing date assigned to that application by the Patent and Trademark Office, or the international application number of the international application, or the international registration number of an international design application. Any correspondence not containing such identification will be returned to the sender where a return address is available. The returned correspondence will be accompanied with a cover letter which will indicate to the sender that if the returned correspondence is resubmitted to the Patent and Trademark Office within two weeks of the mail date on the cover letter, the original date of receipt of the correspondence will be considered by the Patent and Trademark Office as the date of receipt of the correspondence. Applicants may use either the Certificate of Mailing or Transmission procedure under § 1.8 or the Priority Mail Express ® procedure under § 1.10 for resubmissions of returned correspondence if they desire to have the benefit of the date of deposit in the United States Postal Service. If the returned correspondence is not resubmitted within the two-week period, the date of receipt of the resubmission will be considered to be the date of receipt of the correspondence. The two-week period to resubmit the returned correspondence will not be extended. In addition to the application number, all correspondence directed to the Patent and Trademark Office concerning applications for patent should also state the name of the first listed inventor, the title of the invention, the date of filing the same, and if known, the group art unit or other unit within the Patent and Trademark Office responsible for considering the correspondence and the name of the examiner or other person to which it has been assigned.

Jump to MPEP Source · 37 CFR 1.8Title Format RequirementsCorrespondence AddressCorrespondence with the Office
StatutoryRecommendedAlways
[mpep-502-9a3b00303cb47a0a8ca94bd5]
Correspondence for Patent Applications Must Include Specific Information
Note:
All correspondence to the Patent and Trademark Office regarding patent applications must include the application number, inventor’s name, invention title, filing date, art unit, and examiner’s name.

(a) No correspondence relating to an application should be filed prior to receipt of the assigned application number (i.e., U.S. application number, international application number, or international registration number as appropriate). When correspondence directed to the Patent and Trademark Office concerns a previously filed application for a patent, it must identify on the top page in a conspicuous location, the application number (consisting of the series code and the serial number; e.g., 07/123,456), or the serial number and filing date assigned to that application by the Patent and Trademark Office, or the international application number of the international application, or the international registration number of an international design application. Any correspondence not containing such identification will be returned to the sender where a return address is available. The returned correspondence will be accompanied with a cover letter which will indicate to the sender that if the returned correspondence is resubmitted to the Patent and Trademark Office within two weeks of the mail date on the cover letter, the original date of receipt of the correspondence will be considered by the Patent and Trademark Office as the date of receipt of the correspondence. Applicants may use either the Certificate of Mailing or Transmission procedure under § 1.8 or the Priority Mail Express ® procedure under § 1.10 for resubmissions of returned correspondence if they desire to have the benefit of the date of deposit in the United States Postal Service. If the returned correspondence is not resubmitted within the two-week period, the date of receipt of the resubmission will be considered to be the date of receipt of the correspondence. The two-week period to resubmit the returned correspondence will not be extended. In addition to the application number, all correspondence directed to the Patent and Trademark Office concerning applications for patent should also state the name of the first listed inventor, the title of the invention, the date of filing the same, and if known, the group art unit or other unit within the Patent and Trademark Office responsible for considering the correspondence and the name of the examiner or other person to which it has been assigned.

Jump to MPEP Source · 37 CFR 1.8Title Format RequirementsDesign Title RequirementsIdentifying the Application
Topic

Correspondence Address

2 rules
StatutoryInformativeAlways
[mpep-502-dc83bb91224baef3c659b4fe]
Resubmission Within Two Weeks Required
Note:
If correspondence is not resubmitted within two weeks, the date of receipt will be the date of resubmission.

(a) No correspondence relating to an application should be filed prior to receipt of the assigned application number (i.e., U.S. application number, international application number, or international registration number as appropriate). When correspondence directed to the Patent and Trademark Office concerns a previously filed application for a patent, it must identify on the top page in a conspicuous location, the application number (consisting of the series code and the serial number; e.g., 07/123,456), or the serial number and filing date assigned to that application by the Patent and Trademark Office, or the international application number of the international application, or the international registration number of an international design application. Any correspondence not containing such identification will be returned to the sender where a return address is available. The returned correspondence will be accompanied with a cover letter which will indicate to the sender that if the returned correspondence is resubmitted to the Patent and Trademark Office within two weeks of the mail date on the cover letter, the original date of receipt of the correspondence will be considered by the Patent and Trademark Office as the date of receipt of the correspondence. Applicants may use either the Certificate of Mailing or Transmission procedure under § 1.8 or the Priority Mail Express ® procedure under § 1.10 for resubmissions of returned correspondence if they desire to have the benefit of the date of deposit in the United States Postal Service. If the returned correspondence is not resubmitted within the two-week period, the date of receipt of the resubmission will be considered to be the date of receipt of the correspondence. The two-week period to resubmit the returned correspondence will not be extended. In addition to the application number, all correspondence directed to the Patent and Trademark Office concerning applications for patent should also state the name of the first listed inventor, the title of the invention, the date of filing the same, and if known, the group art unit or other unit within the Patent and Trademark Office responsible for considering the correspondence and the name of the examiner or other person to which it has been assigned.

Jump to MPEP Source · 37 CFR 1.8Correspondence AddressCorrespondence with the OfficeBusiness to be Transacted
StatutoryInformativeAlways
[mpep-502-015d00f85fcd4caa9cf8679e]
Two-Week Resubmission Period Not Extendable
Note:
Correspondence returned by the Patent and Trademark Office must be resubmitted within two weeks; this period cannot be extended.

(a) No correspondence relating to an application should be filed prior to receipt of the assigned application number (i.e., U.S. application number, international application number, or international registration number as appropriate). When correspondence directed to the Patent and Trademark Office concerns a previously filed application for a patent, it must identify on the top page in a conspicuous location, the application number (consisting of the series code and the serial number; e.g., 07/123,456), or the serial number and filing date assigned to that application by the Patent and Trademark Office, or the international application number of the international application, or the international registration number of an international design application. Any correspondence not containing such identification will be returned to the sender where a return address is available. The returned correspondence will be accompanied with a cover letter which will indicate to the sender that if the returned correspondence is resubmitted to the Patent and Trademark Office within two weeks of the mail date on the cover letter, the original date of receipt of the correspondence will be considered by the Patent and Trademark Office as the date of receipt of the correspondence. Applicants may use either the Certificate of Mailing or Transmission procedure under § 1.8 or the Priority Mail Express ® procedure under § 1.10 for resubmissions of returned correspondence if they desire to have the benefit of the date of deposit in the United States Postal Service. If the returned correspondence is not resubmitted within the two-week period, the date of receipt of the resubmission will be considered to be the date of receipt of the correspondence. The two-week period to resubmit the returned correspondence will not be extended. In addition to the application number, all correspondence directed to the Patent and Trademark Office concerning applications for patent should also state the name of the first listed inventor, the title of the invention, the date of filing the same, and if known, the group art unit or other unit within the Patent and Trademark Office responsible for considering the correspondence and the name of the examiner or other person to which it has been assigned.

Jump to MPEP Source · 37 CFR 1.8Correspondence AddressCorrespondence with the OfficeBusiness to be Transacted
Topic

Post-Issuance & Maintenance Fees

2 rules
StatutoryRecommendedAlways
[mpep-502-5dc0a038da9e1f6d7fe15c63]
Provide Patent Details for Non-Maintenance Fee Letters
Note:
When a letter pertains to a patent other than paying a maintenance fee, it must include the patent number and issue date, patentee's name, and invention title.

(b) When the letter concerns a patent other than for purposes of paying a maintenance fee, it should state the number and date of issue of the patent, the name of the patentee, and the title of the invention. For letters concerning payment of a maintenance fee in a patent, see the provisions of § 1.366(c).

Jump to MPEP Source · 37 CFR 1.366(c)Post-Issuance & Maintenance FeesMaintenance Fee AmountsFee Requirements
StatutoryInformativeAlways
[mpep-502-a63af214dba5180b8d8fcd7d]
Requirement for Paying Maintenance Fees
Note:
This rule requires that letters concerning payment of a maintenance fee in a patent must follow the provisions outlined in § 1.366(c).

(b) When the letter concerns a patent other than for purposes of paying a maintenance fee, it should state the number and date of issue of the patent, the name of the patentee, and the title of the invention. For letters concerning payment of a maintenance fee in a patent, see the provisions of § 1.366(c).

Jump to MPEP Source · 37 CFR 1.366(c)Post-Issuance & Maintenance FeesMaintenance Fee AmountsFee Requirements
Topic

PTAB Jurisdiction

2 rules
StatutoryInformativeAlways
[mpep-502-d108357e12ba4c07be55f7df]
Correspondence to PTAB Governed by §42.6
Note:
Correspondence related to a trial proceeding before the Patent Trial and Appeal Board must comply with §42.6 of this title.

(c) Correspondence relating to a trial proceeding before the Patent Trial and Appeal Board (part 42 of this title) are governed by § 42.6 of this title.

Jump to MPEP Source · 37 CFR 42.6PTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryPermittedAlways
[mpep-502-fe1d1e776c4b21444b554980]
Facsimile Not Allowed In PTAB Contested Cases
Note:
Facsimile transmissions are not permitted in contested cases and trials before the Patent Trial and Appeal Board, except as expressly authorized by the Board.

(d) Facsimile transmission. Except in the cases enumerated below, correspondence, including authorizations to charge a deposit account, may be transmitted by facsimile. The receipt date accorded to the correspondence will be the date on which the complete transmission is received in the United States Patent and Trademark Office, unless that date is a Saturday, Sunday, or Federal holiday within the District of Columbia. See paragraph (a)(3) of this section. To facilitate proper processing, each transmission session should be limited to correspondence to be filed in a single application or other proceeding before the United States Patent and Trademark Office. The application number of a patent application, the control number of a reexamination or supplemental examination proceeding, the interference number of an interference proceeding, the trial number of a trial proceeding before the Board, or the patent number of a patent should be entered as a part of the sender's identification on a facsimile cover sheet. Facsimile transmissions are not permitted and, if submitted, will not be accorded a date of receipt in the following situations:

(7) In contested cases and trials before the Patent Trial and Appeal Board, except as the Board may expressly authorize.

Jump to MPEP Source · 37 CFR 1.6PTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
Topic

Application Types and Filing

2 rules
StatutoryInformativeAlways
[mpep-502-9c6d2de31276ea5bccf330c4]
Confirmation of Application Transmission Required for Filing Date
Note:
The party transmitting a patent application under §1.53(d) must provide evidence of transmission and a report confirming the transmission to receive a filing date.

(f) Facsimile transmission of a patent application under § 1.53(d). In the event that the Office has no evidence of receipt of an application under § 1.53(d) (a continued prosecution application) transmitted to the Office by facsimile transmission, the party who transmitted the application under § 1.53(d) may petition the Director to accord the application under § 1.53(d) a filing date as of the date the application under § 1.53(d) is shown to have been transmitted to and received in the Office,
(1) Provided that the party who transmitted such application under § 1.53(d):

(iii) Includes a statement which attests on a personal knowledge basis or to the satisfaction of the Director to the previous transmission of the application under § 1.53(d) and is accompanied by a copy of the sending unit’s report confirming transmission of the application under § 1.53(d) or evidence that came into being after the complete transmission and within one business day of the complete transmission of the application under § 1.53(d).

Jump to MPEP Source · 37 CFR 1.53(d)Application Types and FilingContinued Prosecution ApplicationsPTAB Contested Case Procedures
StatutoryPermittedAlways
[mpep-502-2e224453f03bb05e9ca4076b]
Office May Require Proof of Receipt for Continued Prosecution Applications
Note:
The Office may ask for additional evidence to confirm the transmission and receipt of a continued prosecution application on a specific date.

(f) Facsimile transmission of a patent application under § 1.53(d). In the event that the Office has no evidence of receipt of an application under § 1.53(d) (a continued prosecution application) transmitted to the Office by facsimile transmission, the party who transmitted the application under § 1.53(d) may petition the Director to accord the application under § 1.53(d) a filing date as of the date the application under § 1.53(d) is shown to have been transmitted to and received in the Office,

(2) The Office may require additional evidence to determine if the application under § 1.53(d) was transmitted to and received in the Office on the date in question.

Jump to MPEP Source · 37 CFR 1.53(d)Application Types and FilingContinued Prosecution ApplicationsPTAB Contested Case Procedures
Topic

PTAB Contested Case Procedures

2 rules
StatutoryRequiredAlways
[mpep-502-060a89a30f3f0754995920e5]
Requirement for Submitting National Stage Correspondence via USPTO System
Note:
Parties must submit national stage correspondence through the USPTO electronic filing system and can petition for a receipt date if no evidence of submission is found.
(g) Submission of the national stage correspondence required by § 1.495 via the USPTO patent electronic filing system. In the event that the Office has no evidence of receipt of the national stage correspondence required by § 1.495, which was submitted to the Office by the USPTO patent electronic filing system, the party who submitted the correspondence may petition the Director to accord the national stage correspondence a receipt date as of the date the correspondence is shown to have been officially submitted to the Office.
  • (1) The petition of this paragraph (g) requires that the party who submitted such national stage correspondence:
    • (i) Informs the Office of the previous submission of the correspondence promptly after becoming aware that the Office has no evidence of receipt of the correspondence under § 1.495;
    • (ii) Supplies an additional copy of the previously submitted correspondence;
    • (iii) Includes a statement that attests on a personal knowledge basis, or to the satisfaction of the Director, that the correspondence was previously officially submitted; and
    • (iv) Supplies a copy of an acknowledgment receipt generated by the USPTO patent electronic filing system, or equivalent evidence, confirming the submission to support the statement of paragraph (g)(1)(iii) of this section.
  • (2) The Office may require additional evidence to determine if the national stage correspondence was submitted to the Office on the date in question.
Jump to MPEP Source · 37 CFR 1.495PTAB Contested Case Procedures
StatutoryPermittedAlways
[mpep-502-9ea053306e2dcdde24e6fcf9]
Requirement for Additional Evidence to Verify Submission Date
Note:
The Office may demand extra proof to confirm when national stage correspondence was submitted.

(g) Submission of the national stage correspondence required by § 1.495 via the USPTO patent electronic filing system. In the event that the Office has no evidence of receipt of the national stage correspondence required by § 1.495, which was submitted to the Office by the USPTO patent electronic filing system, the party who submitted the correspondence may petition the Director to accord the national stage correspondence a receipt date as of the date the correspondence is shown to have been officially submitted to the Office.

(2) The Office may require additional evidence to determine if the national stage correspondence was submitted to the Office on the date in question.

Jump to MPEP Source · 37 CFR 1.495PTAB Contested Case Procedures
Topic

Certificate of Mailing

1 rules
StatutoryPermittedAlways
[mpep-502-3fde851cc443af509fd4295d]
Resubmission Using Certificate of Mailing or Priority Mail Express
Note:
Applicants can use either the Certificate of Mailing or Transmission procedure or the Priority Mail Express for resubmitting returned correspondence to claim the date of deposit in the U.S. Postal Service.

(a) No correspondence relating to an application should be filed prior to receipt of the assigned application number (i.e., U.S. application number, international application number, or international registration number as appropriate). When correspondence directed to the Patent and Trademark Office concerns a previously filed application for a patent, it must identify on the top page in a conspicuous location, the application number (consisting of the series code and the serial number; e.g., 07/123,456), or the serial number and filing date assigned to that application by the Patent and Trademark Office, or the international application number of the international application, or the international registration number of an international design application. Any correspondence not containing such identification will be returned to the sender where a return address is available. The returned correspondence will be accompanied with a cover letter which will indicate to the sender that if the returned correspondence is resubmitted to the Patent and Trademark Office within two weeks of the mail date on the cover letter, the original date of receipt of the correspondence will be considered by the Patent and Trademark Office as the date of receipt of the correspondence. Applicants may use either the Certificate of Mailing or Transmission procedure under § 1.8 or the Priority Mail Express ® procedure under § 1.10 for resubmissions of returned correspondence if they desire to have the benefit of the date of deposit in the United States Postal Service. If the returned correspondence is not resubmitted within the two-week period, the date of receipt of the resubmission will be considered to be the date of receipt of the correspondence. The two-week period to resubmit the returned correspondence will not be extended. In addition to the application number, all correspondence directed to the Patent and Trademark Office concerning applications for patent should also state the name of the first listed inventor, the title of the invention, the date of filing the same, and if known, the group art unit or other unit within the Patent and Trademark Office responsible for considering the correspondence and the name of the examiner or other person to which it has been assigned.

Jump to MPEP Source · 37 CFR 1.8Certificate of MailingDesign Benefit ClaimsExpress Mail Filing Date
Topic

Supplemental Examination

1 rules
StatutoryRecommendedAlways
[mpep-502-8f6b66b954ea30446ccfc7b3]
Letter Must Identify Reexamination Proceeding
Note:
A letter regarding a reexamination must include the patent number, request control number, and examiner details if known.

(d) A letter relating to a reexamination or supplemental examination proceeding should identify it as such by the number of the patent undergoing reexamination or supplemental examination, the request control number assigned to such proceeding, and, if known, the group art unit and name of the examiner to which it been assigned.

Jump to MPEP Source · 37 CFR 1.5Supplemental Examination
Topic

Documents Excluded from Certificate Practice

1 rules
StatutoryProhibitedAlways
[mpep-502-814d852a6ea9d0317755e9a6]
Fax Submission Prohibited for New Applications
Note:
New patent applications cannot be transmitted by facsimile and do not qualify for a Certificate of Transmission under 37 CFR 1.8.

All applications (provisional and nonprovisional) may be sent to the U.S. Patent and Trademark Office by mail using the United States Postal Service (see MPEP § 501), or they may be hand-carried to the Customer Service Window in Alexandria, Virginia. However, applicants should consider filing new patent applications (as well as patent-related correspondence) via the USPTO patent electronic filing system whenever permitted. See the USPTO Online Filing webpage for additional information on the USPTO patent electronic filing system (www.uspto.gov/patents/apply). See also MPEP § 502.05. New applications cannot be transmitted by facsimile and are not entitled to the benefit of a Certificate of Transmission under 37 CFR 1.8. A request for a continued prosecution application (CPA) filed under 37 CFR 1.53(d) (available only for design applications) may be transmitted to the Office by facsimile (37 CFR 1.6(d)(3)); however, it is not entitled to the benefit of a Certificate of Transmission (see 37 CFR 1.8(a)(2)(i)(A)). See 37 CFR 1.6(d) and MPEP § 502.01.

Jump to MPEP Source · 37 CFR 1.8Documents Excluded from Certificate PracticeCertificate of MailingCertificate of Mailing and Transmission
Topic

Access to Patent Application Files (MPEP 101-106)

1 rules
StatutoryInformativeAlways
[mpep-502-92b75a2832058cc7b12b63a3]
Insufficient Information for Matching Papers to Files
Note:
Papers must include proper application identification (e.g., number and filing date) to be matched with the correct file, especially for amendments and petitions.

All correspondence related to a national patent application already filed with the U.S. Patent and Trademark Office must include the identification of the application number or the serial number and the filing date assigned to the application by the Office. Any correspondence not containing the proper identification set forth in 37 CFR 1.5(a) will be returned to the sender by the Office of Patent Application Processing (OPAP). Each paper should be inspected to assure that the papers being returned contain an “Office Date” stamp indicating the date of receipt. If there is a minor obvious error in the identification of the application such that the Office readily recognizes both the existence of the error and the appropriate correction, the error can be corrected by the Office. The Office often experiences difficulty in matching incoming papers with the application file to which they pertain because insufficient or erroneous information is given. This applies especially to amendments, powers of attorney, changes of address, status letters, petitions for extension of time, and other petitions.

Jump to MPEP Source · 37 CFR 1.5(a)Access to Patent Application Files (MPEP 101-106)Grounds for ReissueReissue Patent Practice
Topic

Application Assignment and Routing

1 rules
StatutoryInformativeAlways
[mpep-502-6f48b98e9517bd01591e6dab]
Items Required for Filed Application Papers
Note:
All incoming papers must include application number, art unit number, filing date, examiner name, title of invention, and confirmation number.
It would be of great assistance to the Office if all incoming papers pertaining to a filed application carried the following items:
  • (A) Application number (checked for accuracy, including series code and serial no.).
  • (B) Art Unit number (copied from most recent Office communication).
  • (C) Filing date.
  • (D) Name of the examiner who prepared the most recent Office action.
  • (E) Title of invention.
  • (F) Confirmation number (see MPEP § 503).
Jump to MPEP Source · 37 CFR 1.6Application Assignment and RoutingApplication Requisites for ExaminationExaminer's Action (37 CFR 1.104)

Examiner Form Paragraphs

Examiner form paragraphs are standard language that you might see in an Office Action or communication from the USPTO. Examiners have latitude to change the form paragraphs, but you will often see this exact language.

¶ 5.01 ¶ 5.01 Proper Heading for Incoming Papers

It would be of great assistance to the Office if all incoming papers pertaining to a filed application carried the following items:

1. Application number (checked for accuracy, including series code and serial no.).

2. Art Unit number (copied from most recent Office communication).

3. Filing date.

4. Name of the examiner who prepared the most recent Office action.

5. Title of invention.

6. Confirmation number (see MPEP § 503 ).

Citations

Primary topicCitation
Certificate of Mailing
Correspondence Address
Identifying the Application
Title Format Requirements
37 CFR § 1.10
Post-Issuance & Maintenance Fees37 CFR § 1.366(c)
Identifying the Application37 CFR § 1.4(f)
PTAB Contested Case Procedures37 CFR § 1.495
Access to Patent Application Files (MPEP 101-106)
Grounds for Reissue
37 CFR § 1.5(a)
Identifying the Application37 CFR § 1.510
Application Types and Filing
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Identifying the Application
37 CFR § 1.53(d)
Continued Prosecution Applications
Documents Excluded from Certificate Practice
37 CFR § 1.6(d)
Continued Prosecution Applications
Documents Excluded from Certificate Practice
37 CFR § 1.6(d)(3)
Identifying the Application37 CFR § 1.610
Certificate of Mailing
Continued Prosecution Applications
Correspondence Address
Documents Excluded from Certificate Practice
Identifying the Application
Title Format Requirements
37 CFR § 1.8
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Identifying the Application
37 CFR § 1.8(a)(2)(i)(A)
Identifying the Application37 CFR § 1.8(a)(2)(iii)(A)
Identifying the Application37 CFR § 1.81
Identifying the Application37 CFR § 1.913
37 CFR § 2.190
PTAB Jurisdiction37 CFR § 42.6
Identifying the Application37 CFR § 5.1
Continued Prosecution Applications
Documents Excluded from Certificate Practice
MPEP § 501
Continued Prosecution Applications
Documents Excluded from Certificate Practice
MPEP § 502.01
Continued Prosecution Applications
Documents Excluded from Certificate Practice
MPEP § 502.05
Application Assignment and RoutingMPEP § 503
Form Paragraph § 5.01

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31