MPEP § 2224 — Correspondence (Annotated Rules)

§2224 Correspondence

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

This page consolidates and annotates all enforceable requirements under MPEP § 2224, 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.

Correspondence

This section addresses Correspondence. Primary authority: 35 U.S.C. 302, 37 CFR 1.1(a)(3), and 37 CFR 1.6(d)(5). Contains: 1 requirement, 1 prohibition, 1 guidance statement, 1 permission, and 1 other statement.

Key Rules

Topic

Ex Parte Reexamination

2 rules
StatutoryProhibitedAlways
[mpep-2224-fc525f4649d0a2b40e00c46f]
FAX Prohibited for Ex Parte Reexamination Requests
Note:
Requests for ex parte reexamination and their corrections cannot be sent by fax, but subsequent correspondence may.

A request for ex parte reexamination may not be sent by facsimile transmission (FAX). See 37 CFR 1.6(d)(5). This is also true for a corrected/completed request sent in response to a notice that the original request was not filing date compliant, since the corrected/completed request stands in place of, or is a completion of, the original request papers. All subsequent ex parte reexamination correspondence, however, may be FAXed to:

Jump to MPEP Source · 37 CFR 1.6(d)(5)Ex Parte Reexamination
StatutoryPermittedAlways
[mpep-2224-24091bdf328142bd3ccab05c]
Ex Parte Reexamination Faxed Correspondence Allowed
Note:
All subsequent ex parte reexamination correspondence may be faxed, except for the initial request which must not be sent by facsimile.

A request for ex parte reexamination may not be sent by facsimile transmission (FAX). See 37 CFR 1.6(d)(5). This is also true for a corrected/completed request sent in response to a notice that the original request was not filing date compliant, since the corrected/completed request stands in place of, or is a completion of, the original request papers. All subsequent ex parte reexamination correspondence, however, may be FAXed to:

Jump to MPEP Source · 37 CFR 1.6(d)(5)Ex Parte Reexamination
Topic

Certificate of Service

1 rules
StatutoryRecommendedAlways
[mpep-2224-b11f24c51ca0a776f59a5aa0]
Address for Ex Parte Reexamination Correspondence
Note:
All ex parte reexamination requests and correspondence should be addressed to the U.S. Patent and Trademark Office via postal mail, except for specific communications directed to the Office of the General Counsel.

All requests for ex parte reexamination filed under 35 U.S.C. 302 (original request papers) and all subsequent ex parte reexamination correspondence mailed to the U.S. Patent and Trademark Office via the U.S. Postal Service Mail, other than correspondence to the Office of the General Counsel pursuant to 37 CFR 1.1(a)(3) and 1.302(e), should be addressed:

Jump to MPEP Source · 37 CFR 1.1(a)(3)Certificate of ServiceTestimony Request ProceduresEx Parte Reexamination Request
Topic

Ex Parte Reexamination Request

1 rules
StatutoryRecommendedAlways
[mpep-2224-a40afefc609b04a6cd27866b]
Identification Requirement for Ex Parte Reexamination Letters
Note:
Letters related to ex parte reexamination must identify the patent, request control number, art unit, and examiner.

After the filing of the request for ex parte reexamination, any letters sent to the U.S. Patent and Trademark Office relating to the resulting ex parte reexamination proceeding should identify the proceeding by the number of the patent undergoing reexamination, the reexamination request control number assigned, the art unit, and the name of the examiner.

Jump to MPEP SourceEx Parte Reexamination RequestEx Parte Reexamination
Topic

Certificate of Mailing

1 rules
StatutoryPermittedAlways
[mpep-2224-a17901e4e6dae2393422433f]
Certificate of Mailing for Ex Parte Reexamination Papers
Note:
Allows the use of certificate of mailing and Priority Mail Express for filing papers in ex parte reexamination except for requests and corrected/replacement requests.

The certificate of mailing and transmission procedures (37 CFR 1.8) may be used to file any paper in an ex parte reexamination proceeding, except for a request for reexamination and a corrected/replacement request for reexamination. This includes the filing of a patent owner’s statement under 37 CFR 1.530, and a requester’s reply under 37 CFR 1.535. See MPEP § 512 as to the use of the certificate of mailing and transmission procedures. The Priority Mail Express® mailing procedure (37 CFR 1.10) may be used to file any paper in an ex parte reexamination proceeding. See MPEP § 513 as to the use of the Priority Mail Express® mailing procedure. Again, the filing of a patent owner’s statement under 37 CFR 1.530, and a requester’s reply under 37 CFR 1.535, are included.

Jump to MPEP Source · 37 CFR 1.8)Certificate of MailingReexamination CertificateRequest by Patent Owner
Topic

Priority Mail Express

1 rules
StatutoryPermittedAlways
[mpep-2224-9869bcb2b5249f6c25c63c87]
Priority Mail Express for Ex Parte Reexamination Filing
Note:
Allows the use of Priority Mail Express to file any paper in an ex parte reexamination proceeding, including patent owner’s statement and requester’s reply.

The certificate of mailing and transmission procedures (37 CFR 1.8) may be used to file any paper in an ex parte reexamination proceeding, except for a request for reexamination and a corrected/replacement request for reexamination. This includes the filing of a patent owner’s statement under 37 CFR 1.530, and a requester’s reply under 37 CFR 1.535. See MPEP § 512 as to the use of the certificate of mailing and transmission procedures. The Priority Mail Express® mailing procedure (37 CFR 1.10) may be used to file any paper in an ex parte reexamination proceeding. See MPEP § 513 as to the use of the Priority Mail Express® mailing procedure. Again, the filing of a patent owner’s statement under 37 CFR 1.530, and a requester’s reply under 37 CFR 1.535, are included.

Jump to MPEP Source · 37 CFR 1.8)Priority Mail ExpressCertificate of Mailing and TransmissionEx Parte Reexamination
Topic

Request by Patent Owner

1 rules
StatutoryInformativeAlways
[mpep-2224-4f5cdb597e718a8cea96158b]
Filing Requirements for Patent Owner’s Statement and Requester’s Reply in Ex Parte Reexamination
Note:
The rule outlines the filing requirements for a patent owner's statement under 37 CFR 1.530 and a requester's reply under 37 CFR 1.535 in an ex parte reexamination proceeding.

The certificate of mailing and transmission procedures (37 CFR 1.8) may be used to file any paper in an ex parte reexamination proceeding, except for a request for reexamination and a corrected/replacement request for reexamination. This includes the filing of a patent owner’s statement under 37 CFR 1.530, and a requester’s reply under 37 CFR 1.535. See MPEP § 512 as to the use of the certificate of mailing and transmission procedures. The Priority Mail Express® mailing procedure (37 CFR 1.10) may be used to file any paper in an ex parte reexamination proceeding. See MPEP § 513 as to the use of the Priority Mail Express® mailing procedure. Again, the filing of a patent owner’s statement under 37 CFR 1.530, and a requester’s reply under 37 CFR 1.535, are included.

Jump to MPEP Source · 37 CFR 1.8)Request by Patent OwnerThird Party RequesterRequest Content Requirements
Topic

Correspondence Address Requirements

1 rules
StatutoryInformativeAlways
[mpep-2224-e6ce73e450905428d331b7a0]
Patent Correspondence Must Be Directed to Reexamined Patent’s Address
Note:
Communications from the U.S. Patent and Trademark Office must be sent to the correspondence address of the patent being reexamined.

Communications from the U.S. Patent and Trademark Office to the patent owner will be directed to the correspondence address for the patent being reexamined. See 37 CFR 1.33(c).

Jump to MPEP Source · 37 CFR 1.33(c)Correspondence Address RequirementsCorrespondence with the OfficeCorrespondence Address
Topic

Correspondence Signature Requirements

1 rules
StatutoryRequiredAlways
[mpep-2224-8df6378025300fdf160c2bf4]
Signature Requirement for Patent Owners' Papers
Note:
Papers filed on behalf of patent owners must be signed by the owner, registered attorney, or agent acting in a representative capacity.

Amendments and other papers filed on behalf of patent owners must be signed by the patent owners, or the registered attorney or agent of record in the patent file, or any registered attorney or agent acting in a representative capacity under 37 CFR 1.34(a). See MPEP § 2213.

Jump to MPEP Source · 37 CFR 1.34(a)Correspondence Signature RequirementsDocuments Requiring SignatureSignature Requirements
Topic

Inter Partes Reexamination

1 rules
StatutoryInformativeAlways
[mpep-2224-14929fef2c6f93e21c0c6ee8]
Requirement for Correspondence in Inter Partes Reexamination
Note:
The rule requires that correspondence be properly formatted and addressed during inter partes reexamination proceedings.

See MPEP § 2624 for correspondence in inter partes reexamination proceedings.

Jump to MPEP SourceInter Partes Reexamination

Citations

Primary topicCitation
Certificate of Service35 U.S.C. § 302
Certificate of Service37 CFR § 1.1(a)(3)
Certificate of Mailing
Priority Mail Express
Request by Patent Owner
37 CFR § 1.10
Correspondence Address Requirements37 CFR § 1.33(c)
Correspondence Signature Requirements37 CFR § 1.34(a)
Certificate of Mailing
Priority Mail Express
Request by Patent Owner
37 CFR § 1.530
Certificate of Mailing
Priority Mail Express
Request by Patent Owner
37 CFR § 1.535
Ex Parte Reexamination37 CFR § 1.6(d)(5)
Certificate of Mailing
Priority Mail Express
Request by Patent Owner
37 CFR § 1.8
Correspondence Signature RequirementsMPEP § 2213
MPEP § 2220
MPEP § 2267
Inter Partes ReexaminationMPEP § 2624
MPEP § 501
Certificate of Mailing
Priority Mail Express
Request by Patent Owner
MPEP § 512
Certificate of Mailing
Priority Mail Express
Request by Patent Owner
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: 2025-12-31