Two things decide whether a job in Wisconsin makes you money: getting the license your work needs, and setting aside the right tax. Wisconsin licenses its contractors and taxes their profit, so both are worth getting right before you take work on.
Each section below points to a tool that runs your exact numbers for Wisconsin.
Tax in Wisconsin
Wisconsin has a graduated state income tax that runs up to 7.65% at the top, on top of your federal taxes. Graduated means the rate climbs as your profit does, so a good year costs proportionally more. You owe federal income tax and self-employment tax as well, and you make estimated payments to both Wisconsin and the IRS through the year.
On sales tax, Wisconsin is one to read carefully. Labor taxable for items remaining TPP after install. Charging tax you should not, or eating tax you should have passed on, comes straight off your margin, so confirm it for your kind of job.
Work out what to hold back on the Tax Set-Aside Calculator, which runs the federal and self-employment numbers for Wisconsin.
Getting paid: liens and retainage
A mechanic's lien is the tool that actually gets a Wisconsin contractor paid, and in Wisconsin you generally have to record it within 6 months of your last day of performing, furnishing or procuring. There is usually an earlier notice to send first, so do not wait until the filing deadline to start. Miss it and you lose the lien, so the dates matter.
Enforcing it has its own clock. 2 years from the date the lien claim was filed. You must also serve a copy of the claim on the owner within 30 days of filing. Work out your dates on the Lien Deadline tool, and if they are close, get an attorney to confirm them against the statute (Wis. Stat. §§779.02(1)(c), 779.02(2)(b), 779.06(1), (2)).
On money held back as retainage, here is where Wisconsin lands:
- Private work: No statutory cap on private work in Wisconsin. Whatever your contract says governs, so read the withholding clause.
- Public work: 5% of the estimate, being the amount and proportionate value of the work done. 5% of the estimate; for a subcontractor, the subcontractor's work completed.
- Release: Private: no number of days is set at all. It falls due on whatever the contract says. Public: no number of days is set at all. It falls due on substantial completion of the work.
- Prompt pay: On state agency work a prime must pay subcontractors within 7 days of receiving payment, with 12% a year compounded monthly from the eighth day, and the same duty cascades to lower tiers. Private work has no deadline, but pay-if-paid clauses are void, while pay-when-paid clauses are allowed.
Whether the rule covers your job at all is a separate question from the percentage. Public, local government: a public contract for construction, repair, remodeling or improvement of a public work or building let by a municipality, which includes the state, towns, cities, villages, school districts and technical college districts, but expressly NOT the Department of Transportation.
And the step-down is not the same thing as a right. Wisconsin cuts the rate to 0% when 50% of the work has been completed. That drop is automatic once the condition is met, so it is money you are entitled to have back before the end of the job. Reinstated only where the architect or engineer CERTIFIES that the job is not proceeding satisfactorily, and even then the total held may not exceed 10% of the value of the work completed. Money already retained is not paid out at the halfway mark.
Heads up: Wisconsin DOT highway work is excluded from the §66.0901 cap by name and §16.867 is not among the sections applied to it, so no statutory retainage percentage for WisDOT was found; only the §16.528 prompt-pay interest reaches it.
Check the Retainage Calculator before you sign a contract that holds back more.
Free Wisconsin retainage letters
Three letters written for Wisconsin's rules, with the state's own release clock and its statutory citation already in them. Fill one in on screen and download it as a PDF or a Word file.
- Retainage Release Request (Wisconsin), for when the job is done and the money has not come back
- Retainage Overdue: Demand for Payment (Wisconsin), for when the release date has passed and nothing has arrived
- Retainage Held Above the Cap: Challenge Letter (Wisconsin), for when more is being held than the state appears to permit
Do you need a license in Wisconsin?
Wisconsin requires a state contractor license to take building work on. The threshold that triggers it: No dollar threshold. A Dwelling Contractor certification is required to OBTAIN A BUILDING PERMIT for a one- or two-family dwelling. Wisconsin has NO statewide license for COMMERCIAL work. Working unlicensed when your job needs a license is the expensive mistake here. There is NO dollar figure anywhere in Wis. Stat. ch. 101 subch. II or SPS 305 determining when the credential is needed, the trigger is obtaining a permit. The only dollar figures are financial-responsibility minimums: a 5,000 bond or 250,000 per-occurrence liability, and a 25,000 line separating Dwelling Contractor from Dwelling Contractor Restricted. That 25,000 is a self-imposed ceiling tied to the contractor's own bond choice; a job at exactly 25,000 under a 25,000 bond IS permitted. Nothing in ch. 101 delegates contractor licensing to municipalities: 101.1472(2) withdraws the department's own rulemaking power without handing anything to local government, so any municipal requirement rests on home-rule powers, and the usual advice to check with your municipality is consistent with the state position rather than underwritten by a statute. The license comes from WI Department of Safety and Professional Services (DSPS). Wisconsin accepts the NASCLA commercial exam, useful if you work across state lines.
Trade licenses for electrical, plumbing and HVAC are usually separate and often required even where a GC license is not. See what applies to your trade on the Contractor License Checker.
Building codes and permits
Wisconsin adopts its building codes statewide, so the rules travel with you across the state. Editions still move, so confirm yours with the building department before you price a job.
- Homes: none; Wisconsin writes its own Uniform Dwelling Code for one- and two-family homes rather than adopting the IRC. Commercial runs the 2021 IBC since 1 September 2025
- Electrical: 2017 for both dwellings and commercial, moving to 2023 for both on 1 September 2026
- Energy: a Wisconsin-written energy chapter inside the dwelling code for houses, with no IECC edition underneath / 2015 IECC for commercial
- Plumbing: Wisconsin's own plumbing code, not the IPC or UPC, with an update effective 1 September 2026
Wisconsin does not run one edition across the whole job, and the electrical code is where it splits: 2017 for both dwellings and commercial, moving to 2023 for both on 1 September 2026. That matters more than the number itself. If you work on houses, the residential edition is your book, and the single figure quoted in most adoption charts is the commercial one.
Wisconsin writes its own codes rather than adopting model ones for three of the four families: the dwelling code, its energy chapter and the plumbing code are all state-authored, so there is no IRC, IECC or IPC edition to quote for a house. Only electrical and the commercial building code sit on model codes. Municipalities may not be more OR less stringent than the state standard, so there is no local variation to check in either direction. Two things land on 1 September 2026: the 2023 NEC for both dwellings and commercial, and an update to the plumbing code. A proposed delay to the electrical date was vetoed, so it stands.
Source: Wis. Admin. Code chapters SPS 320 to 325 (Uniform Dwelling Code), SPS 316 (electrical), SPS 361 to 366 (commercial building, including SPS 363 energy) and SPS 382 (plumbing), Department of Safety and Professional Services, under Wis. Stat. §§101.60, 101.65, 101.70, 101.86 and 145.02; Clearinghouse Rule CR 26-016 (2023 NEC). We have not yet read this row against Wisconsin's own adopting authority, so confirm the edition locally before you rely on it.
Check a specific job on the permit tool.
Pay and workers' comp
The minimum wage in Wisconsin is the federal $7.25 an hour. That is the floor for anyone you put on the books, and it is worth confirming against the state labor department each year because several states step their rate mid-year. Check a rate on the minimum-wage tool.
Workers' comp rates in Wisconsin are not published as a single figure; they turn on your trade's class code and your payroll. Get a realistic range on the Workers' Comp Estimator, then get a real quote.
If a client will not pay
If a client will not pay, you can sue for up to $10,000 in Wisconsin's Circuit Court, Small Claims. That covers most unpaid-invoice disputes for a small outfit; a bigger claim goes to regular civil court where you will probably want an attorney. Walk through whether filing is worth it on the Small Claims checker.
The clock runs the other way too: a client generally has 6 years to sue you over the work under a written contract in Wisconsin, with an absolute cutoff 7 years after the job is substantially complete. Work out your exposure on the Warranty & Claim Deadline tool.
Common questions
How much state income tax will I pay in Wisconsin?
Wisconsin has a graduated rate up to 7.65% state income tax on your profit, on top of federal income tax and self-employment tax. Use the Tax Set-Aside Calculator to see what to hold back.
Do I need a contractor's license in Wisconsin?
Yes. Wisconsin requires a state contractor license. The threshold: No dollar threshold. A Dwelling Contractor certification is required to OBTAIN A BUILDING PERMIT for a one- or two-family dwelling. Wisconsin has NO statewide license for COMMERCIAL work. It is issued by WI Department of Safety and Professional Services (DSPS).
What is the small claims limit in Wisconsin?
You can sue for up to $10,000 in Wisconsin's Circuit Court, Small Claims. The filing fee is typically $22 to $95. Larger claims go to regular civil court.
How long do I have to file a mechanic's lien in Wisconsin?
Generally 6 months from your last day of performing, furnishing or procuring, and there is usually an earlier notice to send first. Miss it and you lose the lien. Work your own dates out on the Lien Deadline tool.
How much retainage can be held back in Wisconsin?
Public, local government: 5% of the estimate, being the amount and proportionate value of the work done. Public, state agency: 5% of the estimate; for a subcontractor, the subcontractor's work completed. The condition on it, in the statute's own terms: Public, local government: a public contract for construction, repair, remodeling or improvement of a public work or building let by a municipality, which includes the state, towns, cities, villages, school districts and technical college districts, but expressly NOT the Department of Transportation. Run your own figure on the Retainage Calculator.
Are there free Wisconsin contract and payment forms?
Yes. This page links 3 retainage letters written to Wisconsin's own release clock and carrying its statutory citation. They are free, there is no sign-up, and you fill one in on screen and download it as a PDF or a Word file.
What is the minimum wage in Wisconsin?
$7.25 an hour, the federal floor. Check a specific job on the minimum-wage tool.
The honest bit
These are the 2026 rules for Wisconsin as they stood when this guide was written, and they change: legislatures move thresholds, deadlines and rates every year. Treat this as general guidance to point you in the right direction, not legal, tax or financial advice. Verify anything you rely on at the source (the IRS, the Wisconsin tax and licensing agencies, and your local building department) or with a professional. Where Wisconsin does something unusual, the detail is called out above rather than glossed over.
Related: Tax Set-Aside Calculator · Mechanic's Lien Deadline · Contractor License Checker · Small Claims checker · Working in Your State
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Sources
- DSPS Home · Wisconsin contractor licensing authority. Who must hold a contractor or trade license in Wisconsin, and the licensing instrument (Wis. Stat. 101.654 (certification); Wis. Admin. Code SPS 305.31)
- Wisconsin statutes (docs.legis.wisconsin.gov) · Mechanics lien notice, filing and enforcement deadlines in Wisconsin: Wis. Stat. §§779.02(1)(c), 779.02(2)(b), 779.06(1), (2). Verified against this authority on 2026-08-12.
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