Wisconsin: Prejudgment Interest Rules
The short answer
Wisconsin courts call this "preverdict interest," and it comes almost entirely from case law rather than a single statute. The common-law rule, unchanged since 1899, allows it only on damages that are liquidated or determinable by a reasonably certain standard -- whether the claim is a contract debt or a tort like conversion -- at the 5% "legal rate." Ordinary personal-injury damages almost never qualify. Separately, and regardless of whether damages are liquidated, a party who serves a formal written settlement offer that the opponent rejects and then loses at trial can collect interest at a different, floating rate (1% plus the prime rate) from the date of that offer. A little-known twist: even a liquidated claim gets no common-law preverdict interest at all if there's more than one defendant, because no single defendant can know its own exact share of liability before the verdict apportions fault.
| Governing law | No comprehensive statute exists. The right to what Wisconsin calls "preverdict interest" is common law, dating to Laycock v. Parker, 103 Wis. 161 (1899), and reaffirmed in Beacon Bowl, Inc. v. Wisconsin Electric Power Co., 176 Wis. 2d 740 (1993); the RATE for that common-law right defaults to Wis. Stat. § 138.04's 5% "legal rate." A separate, independent statutory route, § 807.01(3)-(4) (the settlement-offer statute), lets a party who made a formal written settlement offer collect interest at a different, floating rate if the eventual judgment matches or beats the offer -- available for BOTH liquidated and unliquidated damages |
|---|---|
| Interest rate | 5% a year (the § 138.04 "legal rate") for common-law preverdict interest on a liquidated or determinable claim -- confirmed by case law (Estreen v. Bluhm) applying § 138.04 to this exact purpose. The independent § 807.01(4) settlement-offer route instead uses 1% plus the prime rate, reset every January 1 and July 1 based on the Federal Reserve's H.15 release, and expressly displaces Wisconsin's general post-judgment rate statutes (§§ 814.04(4), 815.05(8)) when it applies -- the two rates are never combined |
| When interest starts running | For common-law preverdict interest: from the date payment was due under the contract, or, if no date was specified, from the date of demand or the date suit was filed (Estreen v. Bluhm). For the independent § 807.01(4) settlement-offer route: from the date of the rejected settlement offer itself, regardless of when the underlying claim arose |
| Contract vs. tort claims | Wisconsin's common-law axis is liquidated-or-determinable versus not, cutting across contract and tort exactly like Arizona's and Washington's: a debt due on a specific date and a tort claim like conversion with a readily ascertainable value both qualify; ordinary personal-injury damages (pain and suffering) almost never do, because a jury has to value them. But Wisconsin adds a further limitation none of those other states have: even a liquidated claim draws NO common-law preverdict interest if there are multiple defendants, because no single defendant can know, before the verdict apportions fault, the exact amount it alone would need to tender to stop interest from accruing (Beacon Bowl, citing Wyandotte Chemicals and City of Franklin). Separately, the § 807.01(4) settlement-offer statute is available for unliquidated tort damages too, confirmed by Graves v. Travelers Insurance Co. -- giving a personal-injury plaintiff who serves a formal offer a real path to preverdict interest the common law alone would deny |
| Mandatory or discretionary | Mandatory ("as a matter of right," not equitable discretion) once damages are shown liquidated or determinable AND there's no multiple-defendant apportionment problem. Wisconsin has no discretionary middle ground the way some states do for unliquidated contract claims -- if damages aren't liquidated or determinable, the common law simply denies preverdict interest outright, an on/off switch rather than a judgment call. The independent § 807.01(4) settlement-offer interest is likewise automatic (not discretionary) once its own three conditions are met: an unaccepted offer, a judgment, and a judgment at or above the offer |
| Simple or compound | Simple interest only. Section 807.01(4)'s settlement-offer interest is confirmed simple, not compound, by case law (Morrison v. Rankin), calculated on a single amount over one continuous period; neither § 138.04 nor the common-law cases mention compounding at all |
| Claims against the government | A debt or contract claim against the STATE itself must first be presented to, and rejected by, the state legislature as a claims bill before a court action can even be filed (§ 775.01) -- a procedural gate, not an interest-specific carve-out; no separate reduced rate or interest exclusion applies once that gate is cleared. A tort claim against a LOCAL government (a county, city, town, or their employees) can be barred entirely, before any interest question is reached, by governmental immunity for "acts done in the exercise of legislative, quasi-legislative, judicial or quasi-judicial functions" under § 893.80(4) -- Wisconsin courts read that to cover any genuinely discretionary act; once liability does attach (a purely ministerial-duty failure, for instance), no separate interest discount or exclusion applies -- ordinary preverdict-interest rules run the same as against a private defendant |
| Other exceptions | The multiple-defendants bar on common-law preverdict interest (see above) is Wisconsin's sharpest, least-obvious exception. Section 807.01(4)'s interest is also exclusive of the general post-judgment rate statutes when it applies -- "interest under this section is in lieu of interest computed under ss. 814.04 (4) and 815.05 (8)," so a plaintiff collects one or the other, never both stacked together. Wisconsin's own courts and statutes use the term "preverdict interest," not "prejudgment interest" -- worth knowing if researching Wisconsin case law directly, since the two terms mean the same thing here |
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The short answer
Wisconsin courts don't use the phrase "prejudgment interest" -- they call it "preverdict interest," and the right to it comes almost entirely from a single 1899 case, not a modern statute. The rule has stayed the same ever since: you can recover preverdict interest only on damages that are liquidated (a fixed, known amount) or determinable by a reasonably certain standard of measurement -- true of many contract debts, and of some tort claims like conversion where the value taken is exactly knowable, but almost never true of ordinary personal-injury damages. When it applies, the rate is 5% a year. Separate from all of that, and available even for damages that aren't liquidated, a party who serves the other side a formal written settlement offer that gets rejected can collect interest at a different rate (1% plus the prime rate) if they eventually win a judgment at least as large as their offer. One more twist unique to Wisconsin: even a liquidated claim gets no common-law preverdict interest at all if there's more than one defendant in the case.
Requirements one by one
Governing law
No Wisconsin statute creates a general right to preverdict interest. That right is entirely common law, running from Laycock v. Parker, 103 Wis. 161 (1899), through Beacon Bowl, Inc. v. Wisconsin Electric Power Co., 176 Wis. 2d 740 (1993), the Wisconsin Supreme Court's most recent full treatment of the subject. Where a statute enters the picture, it's § 138.04, the state's general "legal rate" statute, which case law (not the statute's own text) applies to ground the common-law preverdict-interest rate. A second, entirely independent statute, § 807.01(3)-(4), creates its own separate right to interest tied to a formal settlement offer -- a completely different mechanism from the common-law rule, with its own rate and its own trigger.
Interest rate
For common-law preverdict interest on a liquidated or determinable claim, the rate is 5% a year -- the "legal rate" set by § 138.04, applied to this purpose by case law (Estreen v. Bluhm). The § 807.01(4) settlement-offer statute uses a completely different, floating rate instead: 1% plus the prime rate, reset twice a year (January 1 and July 1) based on the Federal Reserve's own published rate. That statute's own text says its interest is "in lieu of" Wisconsin's general post-judgment rate statutes (§§ 814.04(4) and 815.05(8)), meaning a party gets one rate or the other, never both added together.
When interest starts running
Common-law preverdict interest starts on the date payment was due under the contract; if no due date was specified, it starts from the date a demand was made, or, failing that, from the date suit was filed (Estreen v. Bluhm). The § 807.01(4) settlement-offer route runs on its own separate clock entirely -- from the date of the rejected settlement offer itself, regardless of when the underlying claim first arose.
Contract vs. tort claims
Wisconsin's line is liquidated-or-determinable versus not, cutting across contract and tort exactly the way it does in Arizona and Washington: a fixed contract debt and a tort claim like conversion (where the value of what was taken is readily ascertainable) both qualify for interest as a matter of right, while ordinary personal-injury damages, which need a jury's judgment to value, almost never do. But Wisconsin adds a limitation those other states don't have: even a genuinely liquidated claim gets zero common-law preverdict interest if the case has multiple defendants, because no single defendant could know, before the verdict apportions fault among them, the exact amount it alone would have to pay to stop interest from running. Separately, the § 807.01(4) settlement-offer statute doesn't care whether damages are liquidated at all -- it's confirmed to apply to both liquidated and unliquidated damages alike (Graves v. Travelers Insurance Co.), which gives an ordinary personal-injury plaintiff a real route to preverdict interest that the common law alone would deny them.
Mandatory or discretionary
Once damages are liquidated or determinable and there's no multiple-defendant apportionment problem, common-law preverdict interest is a matter of right, not something left to a court's equitable judgment. Wisconsin doesn't have the middle "discretionary" zone some other states carve out for unliquidated contract claims -- if damages fail the liquidated-or-determinable test, the common law simply provides no preverdict interest at all, full stop. The § 807.01(4) settlement-offer interest is likewise automatic, not discretionary, once its three conditions line up: an offer, a rejection, and a judgment that meets or beats the offer.
Simple or compound
Simple interest only. Case law confirms the § 807.01(4) settlement-offer interest is calculated as simple interest on a single amount over one continuous period, not compounded (Morrison v. Rankin), and neither § 138.04 nor the common-law preverdict-interest cases mention compounding at all.
Claims against the government
A debt or contract claim against the State of Wisconsin itself can't even be filed in court until the state legislature has first been asked to pay the claim as a claims bill and has refused (§ 775.01) -- a procedural precondition rather than a special interest rate or exclusion; nothing in that statute discounts or bars interest once the claim clears that gate. A tort claim against a local government -- a county, city, or town -- can be barred entirely, before any interest question is ever reached, by governmental immunity for "acts done in the exercise of legislative, quasi-legislative, judicial or quasi-judicial functions" under § 893.80(4), which Wisconsin courts read broadly to cover essentially any genuinely discretionary governmental decision. When a local government IS found liable (typically because a duty was purely ministerial, not discretionary), no separate interest discount or carve-out applies -- the same preverdict-interest rules run as against any private defendant.
Other exceptions
The multiple-defendants bar on common-law preverdict interest is Wisconsin's least obvious, most consequential exception -- it can wipe out an otherwise-valid claim to interest on liquidated damages purely because more than one party shares the blame. Separately, § 807.01(4)'s own text makes its interest exclusive of the general post-judgment interest statutes (§§ 814.04(4), 815.05(8)) whenever it applies, so the two never stack. And a purely terminological point worth knowing: Wisconsin courts and statutes call this "preverdict interest," not "prejudgment interest" -- the same concept, different label, which matters if you're reading Wisconsin case law directly.
What trips people up
People often assume that if their damages are clearly calculable, they're entitled to interest from the date of the loss. In Wisconsin, that's true only if there's a single defendant -- add a second defendant to the case, and the common-law right disappears entirely until the § 807.01(4) settlement-offer route is used instead.
Personal-injury plaintiffs sometimes give up on preverdict interest entirely because their damages (pain and suffering, for instance) aren't liquidated. That's the right conclusion under the common law alone -- but it overlooks the independent § 807.01(4) statute, which doesn't require liquidated damages at all and can deliver real preverdict interest if a formal settlement offer is served early and rejected.
Don't assume Wisconsin's 5% common-law rate and its settlement-offer rate are interchangeable or stackable -- they're two separate mechanisms with two separate rates, and § 807.01(4) expressly displaces the general post-judgment rate statutes rather than adding to them.
Common questions
What's Wisconsin's prejudgment ("preverdict") interest rate?
5% a year for the common-law right on a liquidated or determinable claim. A completely separate mechanism -- a formal settlement offer under § 807.01(4) -- uses a different, floating rate (1% plus the prime rate) instead.
Can I get preverdict interest if I sue multiple defendants in Wisconsin?
Not under the common law -- Wisconsin courts have held that multiple defendants preclude an award of preverdict interest even on damages that would otherwise be liquidated, because no one defendant could know its own exact share of liability before the verdict.
Can I get preverdict interest on my personal injury damages?
Not under the common law alone, since pain-and-suffering damages aren't liquidated or determinable. But Wisconsin's separate settlement-offer statute (§ 807.01(4)) covers both liquidated and unliquidated damages, so serving a formal settlement offer early in the case can open a real path to interest.
Does Wisconsin compound preverdict interest?
No. Both the common-law rate and the settlement-offer statute's rate are simple interest.
Statutes and sources
- Wis. Stat. § 138.04 (legal rate) — quoted in full above. Accessed 2026-07-05: https://docs.legis.wisconsin.gov/document/statutes/138.04
- Wis. Stat. § 807.01(4) (settlement-offer interest) — quoted in full above. Accessed 2026-07-05: https://docs.legis.wisconsin.gov/document/statutes/807.01(4)
- Wis. Stat. § 775.01(1) (claims against the state; claims-bill precondition) — quoted in full above. Accessed 2026-07-05: https://docs.legis.wisconsin.gov/document/statutes/775.01
- Wis. Stat. § 893.80(4) (local government immunity for discretionary functions) — quoted in full above. Accessed 2026-07-05: https://docs.legis.wisconsin.gov/document/statutes/893.80(4)
- Beacon Bowl, Inc. v. Wisconsin Electric Power Co., 176 Wis. 2d 740, 776-79 (1993) — the common-law liquidated-or-determinable rule and the multiple-defendants bar. Accessed 2026-07-05: https://www.courtlistener.com/opinion/1308968/beacon-bowl-inc-v-wisconsin-electric-power-co/
- Estreen v. Bluhm, 79 Wis. 2d 142, 255 N.W.2d 473 (1977) (annotated to § 138.04) — the accrual-date rule for a liquidated claim. Accessed 2026-07-05: https://docs.legis.wisconsin.gov/document/statutes/138.04
Source links
Every statute quoted above, linked, with the date we checked it.