37 CFR § 2.62 - Procedure for submitting response.
(a) Deadline. The applicant's response to an Office action must be received by the USPTO within six months from the issue date.
(b) Signature. The response must be signed by the applicant, someone with legal authority to bind the applicant (e.g., a corporate officer or general partner of a partnership), or a practitioner qualified to practice under § 11.14 of this chapter, in accordance with the requirements of § 2.193(e)(2).
(c) Form. Responses must be submitted through TEAS pursuant to § 2.23(a). Responses sent via email or facsimile will not be accorded a date of receipt.