26 CFR § 301.7603-1 - Service of summons.
(a) In general -
(1) Hand delivery or delivery to place of abode. Except as otherwise provided in paragraph (a)(2) of this section, a summons issued under section 6420(e)(2), 6421(g)(2), 6427(j)(2), or 7602 shall be served by an attested copy delivered in hand to the person to whom it is directed, or left at such person's last and usual place of abode.
(2) Summonses issued to third-party recordkeepers. A summons issued under section 6420(e)(2), 6421(g)(2), 6427(j)(2), or 7602 for the production of records (or testimony about such records) by a third-party recordkeeper, as described in section 7603(b)(2) and § 301.7603-2, may also be served by certified or registered mail to the third-party recordkeeper's last known address, as defined in § 301.6212-2. If service to a third-party recordkeeper is made by certified or registered mail, the date of service is the date on which the summons is mailed.
(b) Persons who may serve a summons. The officers and employees of the Internal Revenue Service whom the Commissioner has designated to carry out the authority described in § 301.7602-1(b) to issue a summons are authorized to serve a summons issued under section 6420(e)(2), 6421(g)(2), 6427(j)(2), or 7602.
(c) Effect of certificate of service. The certificate of service signed by the person serving the summons shall be evidence of the facts it states on the hearing of an application for the enforcement of the summons.
(d) Sufficiency of description of summoned records. When a summons requires the production of records, it shall be sufficient if such records are described with reasonable certainty.
(e) Records. For purposes of this section and § 301.7603-2, the term records includes books, papers, or other data.
(f) Effective/applicability date. This section is applicable on April 30, 2008.