Unless displaced by ss. 806.30 to 806.44, the principles of law and equity, including the law relative to the capacity to contract, principal and agent, estoppel, fraud, misrepresentation, duress, coercion, mistake, bankruptcy or other validating or invalidating causes supplement the provisions under ss. 806.30 to 806.44.
806.42.Supplementary general principles of law.
Ch. 806: Judgment · Last amended 1991 · Last verified July 15, 2026
In one sentenceSection 806.42 keeps ordinary principles of law and equity, such as capacity to contract, agency, estoppel, fraud, duress, mistake, and bankruptcy, in force to fill gaps in Wisconsin’s foreign-money claims statutes unless those statutes displace them.
Full Text of Section 806.42
Plain-English Summary
Section 806.42 makes sure the foreign-money claims statutes do not operate in isolation from the rest of Wisconsin law. Unless displaced by Sections 806.30 to 806.44, the principles of law and equity, including the law relative to the capacity to contract, principal and agent, estoppel, fraud, misrepresentation, duress, coercion, mistake, bankruptcy, or other validating or invalidating causes, supplement those provisions.
The practical effect is that ordinary contract and equity defenses remain available in a case built around a foreign-money claim. A party can still raise fraud, duress, or mistake in forming the underlying contract, or point to bankruptcy as affecting the claim, unless the specific text of Sections 806.30 to 806.44 says otherwise for that issue. The section supplements rather than overrides; where the foreign-money claims statutes speak directly to a question, they control.
Frequently Asked Questions
Do general contract defenses like fraud or duress still apply to a foreign-money claim?
Yes, unless displaced by Sections 806.30 to 806.44. Section 806.42 lists fraud, misrepresentation, duress, and coercion among the principles of law and equity that supplement those provisions.
What if the foreign-money claims statutes and general contract law principles conflict?
The statutes control. Section 806.42 supplements Sections 806.30 to 806.44 with general principles of law and equity only “unless displaced by” those sections, so an express provision in the foreign-money claims statutes takes priority.
Does bankruptcy law still matter in a case involving a foreign-money claim?
Yes. Section 806.42 lists bankruptcy among the principles of law and equity that supplement the foreign-money claims provisions.
Can a party still raise an estoppel or mistake defense in a foreign-money claim case?
Yes. Section 806.42 names both estoppel and mistake among the supplementary principles that apply unless the foreign-money claims statutes displace them.
Does Section 806.42 create new law, or does it preserve existing law?
It preserves and supplements existing principles of law and equity rather than creating new substantive rules of its own.
Amendment History
History: 1991 a. 236.
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: general contract defenses foreign money claim wisconsinestoppel fraud foreign currency claim wisconsinuniform foreign money claims act supplementary principles