(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.
801.10.Summons, by whom served.
Ch. 801: Commencement of Action and Venue · Last amended 2005 · Last verified July 15, 2026
In one sentenceSection 801.10 says who may serve a Wisconsin summons — any adult resident of the state of service who isn’t a party, plus certain out-of-state residents serving within Wisconsin — and how service is documented and proven, including when the defendant challenges it.
Full Text of Section 801.10
(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.
Official Notes
Judicial Council Committee’s Note, 1979: Sub. (2) is amended to clarify that the individual who serves the summons on behalf of the plaintiff under the procedures in the Wisconsin Rules of Civil Procedure must indicate on the copy of the summons served both the time and date of service. There is presently a lack of uniformity of interpretation in Wisconsin of the term “time” in s. 801.10 (2). Some jurisdictions interpret it to include time and date of service while other jurisdictions interpret it as only the date of service. Clarifying that both the time and date of service must be indicated in the serving of the summons will insure that this potentially valuable information is noted on the served copy of every summons in Wisconsin. Sub. (4) (a) is amended to also apply the requirement for indicating time and date of service to the affidavits and certificates of service used when proof of service is challenged. [Re Order effective Jan. 1, 1980]
Plain-English Summary
Section 801.10 addresses the mechanics of who can hand-deliver a Wisconsin summons and how that delivery gets documented. The server must be an adult resident of the state where service is made and cannot be a party to the action, and service must be carried out with reasonable diligence. Wisconsin also lets an adult, non-party resident of Illinois, Iowa, Michigan, or Minnesota serve a summons within Wisconsin, recognizing that process servers in border communities often cross state lines.
Once service happens, the server has to sign the summons and note the time, date, place, and manner of service and who was served; a sheriff or deputy must also state their official title. Skipping that endorsement doesn’t undo the service, but it does cost the server the right to collect a fee for it. The server must also prepare and deliver proof of service to whoever asked for the service, who then has to file that proof — though again, failing to make, deliver, or file that proof doesn’t affect whether the underlying service was valid.
The section gets more exacting when a defendant shows up and challenges the service. Personal or substituted service then has to be proved by the server’s affidavit detailing the time, date, place, and manner of service, the server’s qualifying residency, and confirmation the server knew the person served was the named defendant; if service wasn’t personal, the affidavit must also show the reasonable diligence used to try personal service first. A sheriff or deputy serving within their own county may substitute a certificate for that affidavit. Service by publication is proved instead through a publisher’s or printer’s affidavit specifying each publication date, along with an affidavit of mailing. And the defendant’s own written admission of service, with a presumption that a signature on it is genuine, is a third way to prove service was made.
Frequently Asked Questions
Who is allowed to serve a summons in Wisconsin?
Section 801.10 permits any adult resident of the state where service is made, who is not a party to the action, to serve the summons, and it separately allows an adult, non-party resident of Illinois, Iowa, Michigan, or Minnesota to serve a summons within Wisconsin.
What happens if the person serving the summons forgets to note the time and date of service?
Section 801.10 says failing to make that endorsement does not invalidate the service, but the person who served it may not collect a fee for the service.
Does the case fall apart if proof of service is never filed with the court?
No. Section 801.10 provides that failure to make, deliver, or file proof of service does not affect the validity of the underlying service itself.
How is service proved if the defendant challenges whether they were properly served?
Section 801.10 requires an affidavit from the server detailing the time, date, place, and manner of service and the server’s qualifying residency for personal or substituted service, a publisher’s and mailing affidavit for service by publication, or the defendant’s own written admission of service.
Can a sheriff prove service with something other than an affidavit?
Yes. Section 801.10 allows a sheriff or deputy who serves the summons in the county where the defendant was found to use a certificate of service in place of an affidavit.
Amendment History
History: Sup. Ct. Order, 67 Wis. 2d 585, 600 (1975); 1975 c. 218; Sup. Ct. Order, 92 Wis. 2d xiii (1979); 2005 a. 439.
Source & verification. Section text and official notes are
reproduced verbatim from the Wisconsin Statutes, published by the
Wisconsin Legislature (Legislative Reference Bureau). Last verified July 15, 2026.
· Official source
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