Summons, by whom served
Wis. Stat. § 801.10
in effect(1) Who may serve. An authenticated copy of the summons may be served by any adult resident of the state where service is made who is not a party to the action. Service shall be made with reasonable diligence.
(1m) Service by certain nonresidents. Notwithstanding sub. (1), an adult who is not a party to the action and who resides in Illinois, Iowa, Michigan, or Minnesota may serve an authenticated copy of the summons in this state.
(2) Endorsement. At the time of service, the person who serves a copy of the summons shall sign the summons and shall indicate thereon the time and date, place and manner of service and upon whom service was made. If the server is a sheriff or deputy sheriff, the server’s official title shall be stated. Failure to make the endorsement shall not invalidate a service but the server shall not collect fees for the service.
(3) Proof of service. The person making service shall make and deliver proof of service to the person on whose behalf service was made who shall promptly file such proof of service. Failure to make, deliver, or file proof of service shall not affect the validity of the service.
(4) Proof if service challenged. If the defendant appears in the action and challenges the service of summons upon the defendant, proof of service shall be as follows:
(a) Personal or substituted personal service shall be proved by the affidavit of the server indicating the time and date, place and manner of service; that the server is an adult resident of the state of service or, if service is made in this state, an adult resident of this state or of Illinois, Iowa, Michigan, or Minnesota and is not a party to the action; that the server knew the person served to be the defendant named in the summons; and that the server delivered to and left with the defendant an authenticated copy of the summons. If the defendant is not personally served, the server shall state in the affidavit when, where and with whom the copy was left, and shall state such facts as show reasonable diligence in attempting to effect personal service on the defendant. If the copy of the summons is served by a sheriff or deputy sheriff of the county in this state where the defendant was found, proof may be by the sheriff’s or deputy’s certificate of service indicating time and date, place, manner of service and, if the defendant is not personally served, the information required in the preceding sentence. The affidavit or certificate constituting proof of service under this paragraph may be made on an authenticated copy of the summons or as a separate document.
(b) Service by publication shall be proved by the affidavit of the publisher or printer, or the foreman or principal clerk, stating that the summons was published and specifying the date of each insertion, and by an affidavit of mailing of an authenticated copy of the summons, with the complaint or notice of the object of the action, as the case may require, made by the person who mailed the same.
(c) The written admission of the defendant, whose signature or the subscription of whose name to such admission shall be presumptive evidence of genuineness.
Source: WI Statutes (Official Site)URL: https://docs.legis.wisconsin.gov/document/statutes/801.10Fetched: 10/7/2026