MPEP § 511 — Postal Service Interruptions and Emergencies (Annotated Rules)

§511 Postal Service Interruptions and Emergencies

USPTO MPEP version: BlueIron's Update: 2026-01-17

This page consolidates and annotates all enforceable requirements under MPEP § 511, 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.

Postal Service Interruptions and Emergencies

This section addresses Postal Service Interruptions and Emergencies. Primary authority: 35 U.S.C. 21(a), 37 CFR 1.1, and 37 CFR 1.10. Contains: 1 requirement, 3 guidance statements, 6 permissions, and 2 other statements.

Key Rules

Topic

Priority Mail Express

15 rules
StatutoryRecommendedAlways
[mpep-511-36d3393b9044523848eba6a2]
Correct Addresses for Priority Mail Express to USPTO
Note:
The rule specifies the correct addresses for sending Priority Mail Express correspondence to the U.S. Patent and Trademark Office, prohibiting the use of 'Hold for Pickup' service.

The addresses that should be used for Priority Mail Express ® sent to the U.S. Patent and Trademark Office are set forth in 37 CFR 1.1 (see MPEP § 501). The Office does not have resources for picking up any mail. Therefore mail should NOT be sent using the “Hold for Pickup” service option (whereby the mail is retained at the destination postal facility for retrieval by the addressee). Mail sent using the “Hold for pickup” service will not reach the Office.

Jump to MPEP Source · 37 CFR 1.1Priority Mail ExpressCertificate of Mailing and Transmission
StatutoryRecommendedAlways
[mpep-511-afe6eef48cab241160f688cf]
Do Not Use Hold for Pickup Service for Priority Mail Express
Note:
Mail should not be sent using the 'Hold for Pickup' service option as the Office lacks resources to pick up any mail.

The addresses that should be used for Priority Mail Express ® sent to the U.S. Patent and Trademark Office are set forth in 37 CFR 1.1 (see MPEP § 501). The Office does not have resources for picking up any mail. Therefore mail should NOT be sent using the “Hold for Pickup” service option (whereby the mail is retained at the destination postal facility for retrieval by the addressee). Mail sent using the “Hold for pickup” service will not reach the Office.

Jump to MPEP Source · 37 CFR 1.1Priority Mail ExpressCertificate of Mailing and Transmission
StatutoryInformativeAlways
[mpep-511-31b7b7b5e98e85fabb535b96]
Priority Mail Express Must Not Use Hold for Pickup
Note:
Mail sent using the 'Hold for Pickup' service will not reach the U.S. Patent and Trademark Office.

The addresses that should be used for Priority Mail Express ® sent to the U.S. Patent and Trademark Office are set forth in 37 CFR 1.1 (see MPEP § 501). The Office does not have resources for picking up any mail. Therefore mail should NOT be sent using the “Hold for Pickup” service option (whereby the mail is retained at the destination postal facility for retrieval by the addressee). Mail sent using the “Hold for pickup” service will not reach the Office.

Jump to MPEP Source · 37 CFR 1.1Priority Mail ExpressCertificate of Mailing and Transmission
StatutoryInformativeAlways
[mpep-511-52189b9ef21b3a18ad072632]
Requirement for Priority Mail Express Filing
Note:
The rule requires the use of the Priority Mail Express mailing procedure as specified in 37 CFR 1.10.

See MPEP § 513 for the use of the Priority Mail Express ® Mailing procedure of 37 CFR 1.10.

Jump to MPEP Source · 37 CFR 1.10Priority Mail ExpressCertificate of Mailing and Transmission
StatutoryPermittedAlways
[mpep-511-c9e6adc885a09c07e3b535d7]
Petition for Consideration of Unfiled Correspondence Due to Priority Mail Express Interruption
Note:
Allows applicants to petition the Director to consider correspondence and fees as filed on a specific date if unable to be deposited due to an interruption in Priority Mail Express service.

37 CFR 1.10(i) provides a procedure under which applicant may petition the Director to have correspondence (papers and fees) which was unable to be deposited with the United States Postal Service (USPS) because of an interruption or emergency in Priority Mail Express ® service which is so designated by the Director considered as having been filed on a particular date in the Office. Authority for such a practice is found in 35 U.S.C. 21(a). In addition, the Director has designated certain events as a postal service interruption or emergency by rule (37 CFR 1.10(g) and (h)). 37 CFR 1.10(g) provides a procedure under which applicant may petition the Director to have correspondence that was returned by the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. 37 CFR 1.10(h) provides a procedure under which applicant may petition the Director to have correspondence that was refused by an employee of the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. For more information on filing a petition under 37 CFR 1.10(g), (h), or (i), see MPEP § 513, especially subsections IX-XI.

Jump to MPEP Source · 37 CFR 1.10(i)Priority Mail ExpressCertificate of Mailing and TransmissionPetition Procedures (MPEP 1002)
StatutoryInformativeAlways
[mpep-511-4e04ccc49779d42fb4595be2]
Petition for Consideration of Unfiled Correspondence Due to Priority Mail Express Service Interruption
Note:
Allows applicants to petition the Director to consider correspondence as filed on a specific date if it was unable to be deposited due to an interruption in Priority Mail Express service.

37 CFR 1.10(i) provides a procedure under which applicant may petition the Director to have correspondence (papers and fees) which was unable to be deposited with the United States Postal Service (USPS) because of an interruption or emergency in Priority Mail Express ® service which is so designated by the Director considered as having been filed on a particular date in the Office. Authority for such a practice is found in 35 U.S.C. 21(a). In addition, the Director has designated certain events as a postal service interruption or emergency by rule (37 CFR 1.10(g) and (h)). 37 CFR 1.10(g) provides a procedure under which applicant may petition the Director to have correspondence that was returned by the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. 37 CFR 1.10(h) provides a procedure under which applicant may petition the Director to have correspondence that was refused by an employee of the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. For more information on filing a petition under 37 CFR 1.10(g), (h), or (i), see MPEP § 513, especially subsections IX-XI.

Jump to MPEP Source · 37 CFR 1.10(i)Priority Mail ExpressCertificate of Mailing and TransmissionPetition Procedures (MPEP 1002)
StatutoryInformativeAlways
[mpep-511-58244dfc5f832adc787662e9]
Director Designates Events as Postal Service Interruptions
Note:
The Director designates specific events as postal service interruptions, allowing applicants to petition for consideration of correspondence filed on a particular date if affected by these interruptions.

37 CFR 1.10(i) provides a procedure under which applicant may petition the Director to have correspondence (papers and fees) which was unable to be deposited with the United States Postal Service (USPS) because of an interruption or emergency in Priority Mail Express ® service which is so designated by the Director considered as having been filed on a particular date in the Office. Authority for such a practice is found in 35 U.S.C. 21(a). In addition, the Director has designated certain events as a postal service interruption or emergency by rule (37 CFR 1.10(g) and (h)). 37 CFR 1.10(g) provides a procedure under which applicant may petition the Director to have correspondence that was returned by the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. 37 CFR 1.10(h) provides a procedure under which applicant may petition the Director to have correspondence that was refused by an employee of the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. For more information on filing a petition under 37 CFR 1.10(g), (h), or (i), see MPEP § 513, especially subsections IX-XI.

Jump to MPEP Source · 37 CFR 1.10(i)Priority Mail ExpressCertificate of Mailing and TransmissionPetition Procedures (MPEP 1002)
StatutoryPermittedAlways
[mpep-511-5b26f6e837b1e76493860399]
Petition for Consideration of Returned Priority Mail Express Correspondence
Note:
Allows applicants to petition the Director to consider correspondence returned by USPS due to an interruption or emergency in Priority Mail Express service as filed on a specific date.

37 CFR 1.10(i) provides a procedure under which applicant may petition the Director to have correspondence (papers and fees) which was unable to be deposited with the United States Postal Service (USPS) because of an interruption or emergency in Priority Mail Express ® service which is so designated by the Director considered as having been filed on a particular date in the Office. Authority for such a practice is found in 35 U.S.C. 21(a). In addition, the Director has designated certain events as a postal service interruption or emergency by rule (37 CFR 1.10(g) and (h)). 37 CFR 1.10(g) provides a procedure under which applicant may petition the Director to have correspondence that was returned by the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. 37 CFR 1.10(h) provides a procedure under which applicant may petition the Director to have correspondence that was refused by an employee of the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. For more information on filing a petition under 37 CFR 1.10(g), (h), or (i), see MPEP § 513, especially subsections IX-XI.

Jump to MPEP Source · 37 CFR 1.10(i)Priority Mail ExpressCertificate of Mailing and TransmissionMaintenance Fee Payment
StatutoryPermittedAlways
[mpep-511-be5e3d066e2b291cddec1248]
Petition to Consider Refused Priority Mail as Filed
Note:
Allows applicants to petition the Director to consider correspondence refused by USPS due to an interruption or emergency in Priority Mail Express service as filed on a specific date.

37 CFR 1.10(i) provides a procedure under which applicant may petition the Director to have correspondence (papers and fees) which was unable to be deposited with the United States Postal Service (USPS) because of an interruption or emergency in Priority Mail Express ® service which is so designated by the Director considered as having been filed on a particular date in the Office. Authority for such a practice is found in 35 U.S.C. 21(a). In addition, the Director has designated certain events as a postal service interruption or emergency by rule (37 CFR 1.10(g) and (h)). 37 CFR 1.10(g) provides a procedure under which applicant may petition the Director to have correspondence that was returned by the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. 37 CFR 1.10(h) provides a procedure under which applicant may petition the Director to have correspondence that was refused by an employee of the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. For more information on filing a petition under 37 CFR 1.10(g), (h), or (i), see MPEP § 513, especially subsections IX-XI.

Jump to MPEP Source · 37 CFR 1.10(i)Priority Mail ExpressCertificate of Mailing and TransmissionMaintenance Fee Payment
StatutoryInformativeAlways
[mpep-511-a0f093e1e7da7a5785ce6d70]
Petitions for Priority Mail Express Filing Issues
Note:
Provides procedures for filing petitions when correspondence is affected by USPS interruptions or emergencies.

37 CFR 1.10(i) provides a procedure under which applicant may petition the Director to have correspondence (papers and fees) which was unable to be deposited with the United States Postal Service (USPS) because of an interruption or emergency in Priority Mail Express ® service which is so designated by the Director considered as having been filed on a particular date in the Office. Authority for such a practice is found in 35 U.S.C. 21(a). In addition, the Director has designated certain events as a postal service interruption or emergency by rule (37 CFR 1.10(g) and (h)). 37 CFR 1.10(g) provides a procedure under which applicant may petition the Director to have correspondence that was returned by the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. 37 CFR 1.10(h) provides a procedure under which applicant may petition the Director to have correspondence that was refused by an employee of the USPS due to an interruption or emergency in Priority Mail Express ® service considered as filed on a particular date in the Office. For more information on filing a petition under 37 CFR 1.10(g), (h), or (i), see MPEP § 513, especially subsections IX-XI.

Jump to MPEP Source · 37 CFR 1.10(i)Priority Mail ExpressCertificate of Mailing and TransmissionPetition Procedures (MPEP 1002)
StatutoryInformativeAlways
[mpep-511-cba439b29e6803f9b1ced911]
Requirement for Postal Interruption Filing
Note:
The rule states that provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) apply only to postal interruptions and emergencies, not other technical issues.

Applicants are cautioned that the provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) only apply to postal interruptions and emergencies. The provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) do not provide for granting of a filing date to correspondence as of the date on which it would have been filed but for other exigencies, such as the unavailability of a computer or word processing equipment, or the inaccessibility of an office or building other than a USPS facility. 35 U.S.C. 21(a) requires, in part, that “any paper or fee required to be filed in the Patent and Trademark Office…would have been deposited with the United States Postal Service but for postal service interruptions or emergencies designated by the Director.” The statute requires that the correspondence was complete and ready to be deposited with the USPS on the filing date requested (e.g., complete application papers have been prepared and printed) and that the correspondence could not have been deposited with the USPS on the requested filing date for the sole reason that the postal service was not available due to the interruption or emergency designated by the Office.

Jump to MPEP Source · 37 CFR 1.10(g)Priority Mail ExpressCertificate of Mailing and TransmissionMaintenance Fee Amounts
StatutoryInformativeAlways
[mpep-511-d1308a915fe94a143322271e]
Filing Date Not Granted for Non-Postal Exigencies
Note:
The filing date is not granted if correspondence cannot be filed due to non-postal exigencies like equipment unavailability or office inaccessibility.

Applicants are cautioned that the provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) only apply to postal interruptions and emergencies. The provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) do not provide for granting of a filing date to correspondence as of the date on which it would have been filed but for other exigencies, such as the unavailability of a computer or word processing equipment, or the inaccessibility of an office or building other than a USPS facility. 35 U.S.C. 21(a) requires, in part, that “any paper or fee required to be filed in the Patent and Trademark Office…would have been deposited with the United States Postal Service but for postal service interruptions or emergencies designated by the Director.” The statute requires that the correspondence was complete and ready to be deposited with the USPS on the filing date requested (e.g., complete application papers have been prepared and printed) and that the correspondence could not have been deposited with the USPS on the requested filing date for the sole reason that the postal service was not available due to the interruption or emergency designated by the Office.

Jump to MPEP Source · 37 CFR 1.10(g)Priority Mail ExpressCertificate of Mailing and TransmissionMaintenance Fee Amounts
StatutoryRecommendedAlways
[mpep-511-df9ee40c78dc6031684c0e9f]
New Patent Applications Must Be Filed Electronically
Note:
Applicants should file new patent applications and related correspondence via the USPTO's Patent Center whenever possible, as per the Legal Framework for Patent Electronic System.

In general, applicants should consider filing new patent applications (as well as patent-related correspondence) via the USPTO patent electronic filing system (Patent Center) whenever permitted. See the Legal Framework for Patent Electronic System posted on the USPTO website (www.uspto.gov/PatentLegalFramework) for information pertaining to the types of patent applications and documents that are permitted to be filed via the USPTO patent electronic filing system. 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. New patent applications may also be hand-delivered to the Office. See MPEP § 501.

Jump to MPEP Source · 37 CFR 1.8Priority Mail ExpressCertificate of Mailing and TransmissionContinued Prosecution Applications
StatutoryPermittedAlways
[mpep-511-f1398f368ff52e71eef34c7e]
New Patent Applications May Be Hand-Delivered
Note:
Patent applications can be submitted in person to the Office, in addition to electronic filing through Patent Center.

In general, applicants should consider filing new patent applications (as well as patent-related correspondence) via the USPTO patent electronic filing system (Patent Center) whenever permitted. See the Legal Framework for Patent Electronic System posted on the USPTO website (www.uspto.gov/PatentLegalFramework) for information pertaining to the types of patent applications and documents that are permitted to be filed via the USPTO patent electronic filing system. 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. New patent applications may also be hand-delivered to the Office. See MPEP § 501.

Jump to MPEP Source · 37 CFR 1.8Priority Mail ExpressCertificate of Mailing and TransmissionContinued Prosecution Applications
StatutoryPermittedAlways
[mpep-511-0fbf752554be8a38e2435ea3]
Methods for Filing Patent Correspondence
Note:
Patent correspondence can be filed via USPS, hand-delivery, or electronic/fax systems when permitted. Applicants must use certificates of mailing/transmission if required.

Correspondence in a patent application can be filed via the USPS, hand-delivery, or, when permitted, via the USPTO patent electronic filing system or facsimile. Applicants should file correspondence with a Certificate of Mailing or a Certificate of Transmission under 37 CFR 1.8 when permitted. See MPEP §§ 502.01 and 512. Even if the post office is closed due to an emergency, applicants should ordinarily be able to deposit correspondence in a mailbox for first class mail.

Jump to MPEP Source · 37 CFR 1.8Priority Mail ExpressExpress Mail FilingCertificate of Mailing and Transmission
Topic

Certificate of Mailing

2 rules
StatutoryInformativeAlways
[mpep-511-ff41f674a981f206b43fc528]
Requirement for Filing New Applications by Priority Mail Express
Note:
Applicants must file new applications via Priority Mail Express to ensure the date of deposit is used as the filing date, unless filed electronically.

The Office strongly recommends that applicants file new applications by Priority Mail Express ® in accordance with 37 CFR 1.10 (if such applications are not filed via the USPTO patent electronic filing system) because such correspondence will be accorded the date of deposit in Priority Mail Express ® with the USPS as the filing date. See 37 CFR 1.6(a) and MPEP § 513. Applications that are not filed by Priority Mail Express ® can only be accorded the date of receipt in the Office as the filing date (unless there is a postal interruption or emergency designated by the Office and applicants are instructed to file their applications in a manner other than by Priority Mail Express ®), thus any applicant who files an application by first class mail bears the risk of any delay in the delivery of the application to the Office, even if the delay is unusually significant due to some unforeseen event.

Jump to MPEP Source · 37 CFR 1.10Certificate of MailingPriority Mail ExpressCertificate of Mailing and Transmission
StatutoryPermittedAlways
[mpep-511-5ab747fdc34e908b6961a08d]
Priority Mail Express Required for Filing Date
Note:
Applications must be filed via Priority Mail Express unless otherwise instructed by the Office, bearing the risk of delayed filing dates due to postal issues.

The Office strongly recommends that applicants file new applications by Priority Mail Express ® in accordance with 37 CFR 1.10 (if such applications are not filed via the USPTO patent electronic filing system) because such correspondence will be accorded the date of deposit in Priority Mail Express ® with the USPS as the filing date. See 37 CFR 1.6(a) and MPEP § 513. Applications that are not filed by Priority Mail Express ® can only be accorded the date of receipt in the Office as the filing date (unless there is a postal interruption or emergency designated by the Office and applicants are instructed to file their applications in a manner other than by Priority Mail Express ®), thus any applicant who files an application by first class mail bears the risk of any delay in the delivery of the application to the Office, even if the delay is unusually significant due to some unforeseen event.

Jump to MPEP Source · 37 CFR 1.10Certificate of MailingPriority Mail ExpressCertificate of Mailing and Transmission
Topic

Fee Requirements

1 rules
StatutoryRequiredAlways
[mpep-511-ed5e33bf0614d42e944abe4d]
Filing Considered Filed During Postal Disruptions
Note:
The Director may require that papers or fees filed with the United States Postal Service be considered as filed in the Patent and Trademark Office even during postal service interruptions.

(a) The Director may by rule prescribe that any paper or fee required to be filed in the Patent and Trademark Office will be considered filed in the Office on the date on which it was deposited with the United States Postal Service or would have been deposited with the United States Postal Service but for postal service interruptions or emergencies designated by the Director.

Jump to MPEP SourceFee Requirements
Topic

Maintenance Fee Amounts

1 rules
StatutoryRequiredAlways
[mpep-511-067cf9e39144c517e3217020]
Requirement for Filing During USPS Intermittencies
Note:
This rule requires that any paper or fee required to be filed with the Patent and Trademark Office must have been deposited with the United States Postal Service if not for postal service interruptions designated by the Director.

Applicants are cautioned that the provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) only apply to postal interruptions and emergencies. The provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) do not provide for granting of a filing date to correspondence as of the date on which it would have been filed but for other exigencies, such as the unavailability of a computer or word processing equipment, or the inaccessibility of an office or building other than a USPS facility. 35 U.S.C. 21(a) requires, in part, that “any paper or fee required to be filed in the Patent and Trademark Office…would have been deposited with the United States Postal Service but for postal service interruptions or emergencies designated by the Director.” The statute requires that the correspondence was complete and ready to be deposited with the USPS on the filing date requested (e.g., complete application papers have been prepared and printed) and that the correspondence could not have been deposited with the USPS on the requested filing date for the sole reason that the postal service was not available due to the interruption or emergency designated by the Office.

Jump to MPEP Source · 37 CFR 1.10(g)Maintenance Fee AmountsPriority Mail ExpressCertificate of Mailing and Transmission
Topic

Maintenance Fee Payment

1 rules
StatutoryInformativeAlways
[mpep-511-eafc47461df166c90ad8b725]
Filing Date Not Affected by Unavailability of USPS
Note:
The filing date is not granted if the correspondence was complete and ready for USPS but could not be deposited due to postal service interruptions or emergencies designated by the Office.

Applicants are cautioned that the provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) only apply to postal interruptions and emergencies. The provisions of 35 U.S.C. 21(a) and 37 CFR 1.10(g) to (i) do not provide for granting of a filing date to correspondence as of the date on which it would have been filed but for other exigencies, such as the unavailability of a computer or word processing equipment, or the inaccessibility of an office or building other than a USPS facility. 35 U.S.C. 21(a) requires, in part, that “any paper or fee required to be filed in the Patent and Trademark Office…would have been deposited with the United States Postal Service but for postal service interruptions or emergencies designated by the Director.” The statute requires that the correspondence was complete and ready to be deposited with the USPS on the filing date requested (e.g., complete application papers have been prepared and printed) and that the correspondence could not have been deposited with the USPS on the requested filing date for the sole reason that the postal service was not available due to the interruption or emergency designated by the Office.

Jump to MPEP Source · 37 CFR 1.10(g)Maintenance Fee PaymentPriority Mail ExpressMaintenance Fee Amounts
Topic

Documents Excluded from Certificate Practice

1 rules
StatutoryProhibitedAlways
[mpep-511-e409195866ba287adc84f758]
New Applications Cannot Use Fax
Note:
Patent applications cannot be transmitted by facsimile and do not qualify for a Certificate of Transmission under 37 CFR 1.8.

In general, applicants should consider filing new patent applications (as well as patent-related correspondence) via the USPTO patent electronic filing system (Patent Center) whenever permitted. See the Legal Framework for Patent Electronic System posted on the USPTO website (www.uspto.gov/PatentLegalFramework) for information pertaining to the types of patent applications and documents that are permitted to be filed via the USPTO patent electronic filing system. 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. New patent applications may also be hand-delivered to the Office. See MPEP § 501.

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

Continued Prosecution Applications

1 rules
StatutoryPermittedAlways
[mpep-511-1bf7cd97973b5a24a0a9fa05]
Filing of Design Continued Prosecution Applications by Facsimile
Note:
A request for a design continued prosecution application can be filed via facsimile but does not qualify for a Certificate of Transmission.

In general, applicants should consider filing new patent applications (as well as patent-related correspondence) via the USPTO patent electronic filing system (Patent Center) whenever permitted. See the Legal Framework for Patent Electronic System posted on the USPTO website (www.uspto.gov/PatentLegalFramework) for information pertaining to the types of patent applications and documents that are permitted to be filed via the USPTO patent electronic filing system. 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. New patent applications may also be hand-delivered to the Office. See MPEP § 501.

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

Certificate of Mailing

1 rules
StatutoryRecommendedAlways
[mpep-511-849269edc65d114db8212ddb]
Certificate of Mailing Required for Permitted Correspondence
Note:
Applicants must file correspondence via USPS, electronic system, or facsimile with a Certificate of Mailing when permitted.

Correspondence in a patent application can be filed via the USPS, hand-delivery, or, when permitted, via the USPTO patent electronic filing system or facsimile. Applicants should file correspondence with a Certificate of Mailing or a Certificate of Transmission under 37 CFR 1.8 when permitted. See MPEP §§ 502.01 and 512. Even if the post office is closed due to an emergency, applicants should ordinarily be able to deposit correspondence in a mailbox for first class mail.

Jump to MPEP Source · 37 CFR 1.8Certificate of MailingCertificate of Mailing and Transmission
Topic

Express Mail Requirements

1 rules
StatutoryRecommendedAlways
[mpep-511-8124269b1f1a6859a7d164fa]
Mailbox Deposit for First Class Mail During Emergencies
Note:
Applicants should deposit correspondence in a mailbox for first class mail even if the post office is closed due to an emergency.

Correspondence in a patent application can be filed via the USPS, hand-delivery, or, when permitted, via the USPTO patent electronic filing system or facsimile. Applicants should file correspondence with a Certificate of Mailing or a Certificate of Transmission under 37 CFR 1.8 when permitted. See MPEP §§ 502.01 and 512. Even if the post office is closed due to an emergency, applicants should ordinarily be able to deposit correspondence in a mailbox for first class mail.

Jump to MPEP Source · 37 CFR 1.8Express Mail RequirementsCertificate of MailingPriority Mail Express

Citations

Primary topicCitation
Maintenance Fee Amounts
Maintenance Fee Payment
Priority Mail Express
35 U.S.C. § 21(a)
Priority Mail Express37 CFR § 1.1
Certificate of Mailing
Priority Mail Express
37 CFR § 1.10
Maintenance Fee Amounts
Maintenance Fee Payment
Priority Mail Express
37 CFR § 1.10(g)
Priority Mail Express37 CFR § 1.10(h)
Priority Mail Express37 CFR § 1.10(i)
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Priority Mail Express
37 CFR § 1.53(d)
Certificate of Mailing37 CFR § 1.6(a)
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Priority Mail Express
37 CFR § 1.6(d)
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Priority Mail Express
37 CFR § 1.6(d)(3)
Certificate of Mailing
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Express Mail Requirements
Priority Mail Express
37 CFR § 1.8
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Priority Mail Express
37 CFR § 1.8(a)(2)(i)(A)
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Priority Mail Express
MPEP § 501
Certificate of Mailing
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Express Mail Requirements
Priority Mail Express
MPEP § 502.01
Continued Prosecution Applications
Documents Excluded from Certificate Practice
Priority Mail Express
MPEP § 502.05
Certificate of Mailing
Priority Mail Express
MPEP § 513

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: 2026-01-17