37 CFR § 1.33 - Correspondence respecting patent applications, patent reexamination proceedings, and other proceedings.
(a) Correspondence address and daytime telephone number. When filing an application, a correspondence address must be set forth in either an application data sheet (§ 1.76), or elsewhere, in a clearly identifiable manner, in any paper submitted with an application filing. If no correspondence address is specified, the Office may treat the mailing address of the first named inventor (if provided, see §§ 1.76(b)(1) and 1.63(b)(2)) as the correspondence address. The Office will direct, or otherwise make available, all notices, official letters, and other communications relating to the application to the person associated with the correspondence address. For correspondence submitted via the Office's electronic filing system, however, an electronic acknowledgment receipt will be sent to the submitter. The Office will generally not engage in double correspondence with an applicant and a patent practitioner, or with more than one patent practitioner except as deemed necessary by the Director. If more than one correspondence address is specified, the Office will select one of the specified addresses for use as the correspondence address and, if given, may select the address associated with a Customer Number over a typed correspondence address. For the party to whom correspondence is to be addressed, a daytime telephone number should be supplied in a clearly identifiable manner and may be changed by any party who may change the correspondence address. The correspondence address may be changed by the parties set forth in paragraph (b)(1) or (b)(3) of this section. Prior to the appointment of any power of attorney under § 1.32(b), the correspondence address may also be changed by any patent practitioner named in the application transmittal papers who acts in a representative capacity under the provisions of § 1.34.
(b) Amendments and other papers. Amendments and other papers, except for written assertions pursuant to § 1.27(c)(2)(iii) or (c)(2)(iv), filed in the application must be signed by:
(1) A patent practitioner of record;
(2) A patent practitioner not of record who acts in a representative capacity under the provisions of § 1.34; or
(c) All notices, official letters, and other communications for the patent owner or owners in a reexamination or supplemental examination proceeding will be directed to the correspondence address in the patent file. Amendments filed in a reexamination proceeding, and other papers filed in a reexamination or supplemental examination proceeding, on behalf of the patent owner must be signed by the patent owner, or if there is more than one owner by all the owners, or by an attorney or agent of record in the patent file, or by a registered attorney or agent not of record who acts in a representative capacity under the provisions of § 1.34. Double correspondence with the patent owner or owners and the patent owner's attorney or agent, or with more than one attorney or agent, will not be undertaken.
(d) A “correspondence address” or change thereto may be filed with the Patent and Trademark Office during the enforceable life of the patent. The “correspondence address” will be used in any correspondence relating to maintenance fees unless a separate “fee address” has been specified. See § 1.363 for “fee address” used solely for maintenance fee purposes.
(e) A change of address filed in a patent application or patent does not change the address for a patent practitioner in the roster of patent attorneys and agents. See § 11.11 of this title.
(f) Where application papers from a prior application are used in a continuing application and the correspondence address was changed during the prosecution of the prior application, an application data sheet or separate paper identifying the correspondence address to be used for the continuing application must be submitted. Otherwise, the Office may not recognize the change of correspondence address effected during the prosecution of the prior application.
(g) A patent practitioner acting in a representative capacity whose correspondence address is the correspondence address of record in an application may change the correspondence address after the patent has issued, provided that the change of correspondence address is accompanied by a statement that notice has been given to the patentee or owner.