(1) At any time after commencement of the action, a defending party, as a 3rd-party plaintiff, may cause a summons and complaint to be served upon a person not a party to the action who is or may be liable to the defending party for all or part of the plaintiff’s claim against the defending party, or who is a necessary party under s. 803.03. The 3rdparty plaintiff need not obtain leave to implead if he or she serves the 3rd-party summons and 3rd-party complaint not later than 6 months after the summons and complaint are filed or the time set in a scheduling order under s. 802.10; thereafter, the 3rd-party plaintiff must obtain leave on motion upon notice to all parties to the action. The person served with the summons and 3rd-party complaint, hereinafter called the 3rd-party defendant, shall make defenses to the 3rd-party plaintiff’s claim as provided in s. 802.06 and counterclaims against the 3rd-party plaintiff and cross claims against any other defendant as provided in s. 802.07. The 3rdparty defendant may assert against the plaintiff any defenses which the 3rd-party plaintiff has to the plaintiff’s claim. The 3rdparty defendant may also assert any claim against the plaintiff if the claim is based upon the same transaction, occurrence or series of transactions or occurrences as is the plaintiff’s claim against the 3rd-party plaintiff. The plaintiff may assert any claim against the 3rd-party defendant if the claim is based upon the same transaction, occurrence or series of transactions or occurrences as is the plaintiff’s claim against the 3rd-party plaintiff, and the 3rdparty defendant thereupon shall assert defenses as provided in s. 802.06 and counterclaims and cross claims as provided in s. 802.07.
803.05.Third-party practice.
Ch. 803: Parties · Last amended 2007 · Last verified July 15, 2026
In one sentenceSection 803.05 lets a defendant bring in a third party who may owe it all or part of what the plaintiff is claiming, without needing the court’s permission if it acts within six months of filing, and it lays out how the plaintiff, the third-party defendant, and the original defendant can then assert claims against each other.
Full Text of Section 803.05
(2) When a counterclaim is asserted against a plaintiff, the plaintiff may cause a 3rd party to be brought in under circumstances which under this section would entitle a defendant to do so.
Official Notes
Judicial Council Committee’s Note, 1977: Sub. (1) has been amended to allow a third-party plaintiff to serve the third-party summons and third-party complaint without leave of the court to implead if the third-party summons and third-party complaint are filed not later than 6 months after the summons and complaint in the original action are filed. The new six-month time period has been created since the old time period allowing a third-party plaintiff to file a third-party summons and third-party complaint without the need to obtain leave to implead during the time set in a scheduling order under s. 802.10 can no longer apply in most cases. The use of such a scheduling order is now completely discretionary with the trial judge. [Re Order effective July 1, 1978]
Judicial Council Note, 1988: Sub. (3) [created] allows oral argument permitted on motions under this section to be heard by telephone conference. [Re Order effective Jan. 1, 1988]
Plain-English Summary
A defending party, as third-party plaintiff, may serve a summons and complaint on a nonparty who is or may be liable to it for all or part of the plaintiff’s claim, or who is a necessary party under section 803.03. No leave of court is needed if the third-party summons and complaint are served within six months after the summons and complaint were filed, or within the time a scheduling order under section 802.10 sets; after that, the third-party plaintiff must obtain leave on motion, with notice to all parties.
The third-party defendant answers under section 802.06 and may counterclaim or cross-claim under section 802.07. It may also assert against the plaintiff any defense the original defendant has to the plaintiff’s claim, and any claim of its own that arises from the same transaction, occurrence, or series as the plaintiff’s claim against the original defendant. The plaintiff, in turn, may assert a claim against the third-party defendant on that same transactional basis, which then obligates the third-party defendant to raise its own defenses under section 802.06 and counterclaims or cross claims under section 802.07 in response.
A plaintiff facing a counterclaim can bring in a third party under the same circumstances that would let a defendant do so, and oral argument on motions under this section may be heard by telephone under section 807.13(1).
Frequently Asked Questions
Can a Wisconsin defendant bring in someone else who might be responsible for the plaintiff’s claim?
Yes. Section 803.05 lets a defending party implead a nonparty who is or may be liable to it for all or part of the plaintiff’s claim.
Does a defendant need the court’s permission to file a third-party complaint?
Not if it is served within six months after the summons and complaint were filed, or within the time set by a scheduling order; after that, leave of court on notice to all parties is required.
Can the third-party defendant raise defenses the original defendant has against the plaintiff?
Yes. The third-party defendant may assert against the plaintiff any defenses the third-party plaintiff has to the plaintiff’s claim.
Can the plaintiff bring a claim directly against the third-party defendant?
Yes, if the claim arises from the same transaction, occurrence, or series as the plaintiff’s claim against the original defendant.
Can a plaintiff who faces a counterclaim implead a third party too?
Yes. Section 803.05(2) lets a plaintiff bring in a third party under the same circumstances that would let a defendant do so.
Amendment History
History: Sup. Ct. Order, 67 Wis. 2d 585, 648 (1975); 1975 c. 218; Sup. Ct. Order, 82 Wis. 2d ix (1978); Sup. Ct. Order, 141 Wis. 2d xiii (1987); 2005 a. 253; 2007 a. 97.
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
Also known as: wisconsin third party complaintimpleader rule wisconsinthird party defendant wisconsin lawsuitbringing in a third party without court permission wisconsin