Before you start

An SSN or ITIN
Form W-4 with your employer for federal withholding
Wisconsin Form WT-4 with your employer for state withholding
Records of foreign income and foreign financial accounts

Step-by-step

1
Complete the federal W-4 and Wisconsin Form WT-4 on day one
Wisconsin has its own withholding exemption certificate separate from the federal W-4, and its rules differ enough that copying your federal figures across produces the wrong withholding. There is no additional city or county form, because no Wisconsin municipality levies an income tax — a genuinely simpler payroll setup than Ohio, Indiana, Kentucky or New York.
Via employerWho: YouFirst week of employment
2
Find your actual bracket rather than reading the top rate
For 2025 a single filer pays 3.50% to USD 14,680, 4.40% to USD 50,480, 5.30% to USD 323,290 and 7.65% above. Joint filers get 3.50% to USD 19,580, 4.40% to USD 67,300 and 5.30% to USD 431,060. Wisconsin's reputation as a high-tax state comes from the 7.65% top rate, which almost nobody reaches. Run your own number: for a professional salary the marginal rate here is 5.30%.
OnlineWho: You
3
Understand the property tax before you buy, because that is where Wisconsin collects
Wisconsin assesses at full market value rather than at a fraction of it, so the assessed value on your bill is meant to be roughly what the house is worth — unlike Kansas's 11.5% or Yonkers's 1.4%. The City Assessor's 2025 report puts the average Madison single-family assessment at USD 481,300, and the tax on the average home was USD 8,095.57 for 2024. Bills come from the City of Madison and can be paid in full by 31 January or in four instalments to 31 July.
OnlineWho: You
4
Check the Lottery and Gaming Credit and First Dollar Credit are on your bill
Wisconsin applies two automatic reductions to an owner-occupied bill — the Lottery and Gaming Credit, worth USD 268.94 on the 2024 Madison bill, and the First Dollar Credit at USD 83.53. They are applied by the municipality, but a newly purchased property sometimes has the Lottery credit missing because the owner-occupancy certification did not follow the sale. Check the bill rather than assuming.
OnlineWho: You
5
Claim the Homestead Credit if you are eligible — including as a renter
Wisconsin's Homestead Credit is one of very few American property tax credits a tenant can claim. Eligibility for 2025 requires household income below USD 24,680, and the credit is computed from the relationship between that income and the property tax or rent you paid. Graduate students, postdocs and part-year arrivals are exactly the people who qualify and never claim.
OnlineWho: You
6
Determine your US tax residency and check for a treaty
The substantial presence test counts weighted days across three years to decide whether the US taxes your worldwide income or only US-source income, and certain students and scholars are exempt from counting days for a period — which matters a great deal at UW-Madison. Wisconsin's return starts from federal adjusted gross income, so a federal treaty exclusion generally flows through to the state.
OnlineWho: You

Documents you’ll need

Form W-2 from each employer, issued by 31 January
Form 1099s for freelance, interest and investment income
Wisconsin Form 1 individual income tax return, and Schedule H for the Homestead Credit
Passport and travel history for the substantial presence day count
Foreign account statements for FBAR reporting

Things most newcomers don’t know

Wisconsin's 7.65% top rate is a bad summary of what you will actually pay.

The Department of Revenue's own schedule puts the 5.30% band from USD 50,480 to USD 323,290 for a single filer — an enormous span that captures almost every professional salary in Madison. The 4.40% band now reaches USD 50,480 single and USD 67,300 joint, which is materially wider than it used to be. So the marginal rate a newcomer actually meets is 4.40% or 5.30%, not 7.65%, and Wisconsin compares far better against Minnesota's 9.85% or New York's 10.9% than the headline suggests.

Source: Wisconsin Department of Revenue — tax rates

Madison's sales tax is 5.5% and Milwaukee's is 7.9%, in the same state.

Wisconsin charges 5% and seventy of its seventy-two counties add 0.5%, Dane included. Milwaukee is the only city in Wisconsin permitted to levy its own sales tax and takes 2%, sitting on top of Milwaukee County's 0.9%. Madison's combined 5.5% is among the lowest of any large American city and is a real recurring saving on everything you buy — and the gap is invisible in any state-level comparison of Wisconsin against its neighbours.

Source: Wisconsin Department of Revenue — tax rates

Wisconsin assesses at full market value, which changes how you read a tax bill.

Kansas assesses residential property at 11.5% of market value and Yonkers's residential assessment ratio is about 1.4%, so in both places the assessed value is a fraction and the mill rate is enormous. Wisconsin assesses at market value, so the number on your bill should approximate what the house is worth and the rate is directly comparable to a percentage. The City of Madison's own report puts the average single-family assessment at USD 481,300 and the 2024 tax on the average home at USD 8,095.57 — roughly 1.8% a year.

Source: City of Madison Assessor — 2025 Property Tax Base Report

Madison assessments rose 12.4% and 12.6% in consecutive years, and that is the housing market talking.

The Assessor's own series takes the average single-family assessment from USD 300,600 in 2019 to USD 481,300 in 2025. A capital city, a 50,000-student flagship university and Epic's Verona campus all draw on a market physically constrained by two lakes and an isthmus. If you are reading a Wisconsin cost-of-living figure and applying it to Madison, you are reading the wrong city — this market behaves like a coastal college town, not like the rest of the state.

Source: City of Madison Assessor — 2025 Property Tax Base Report

Common mistakes to avoid

Judging Wisconsin on its 7.65% top rate when the 5.30% band runs to USD 323,290 for a single filer.
Applying Milwaukee's 7.9% sales tax to a Madison budget — Madison is 5.5%.
Reading a Wisconsin-average housing cost and applying it to Madison.
Buying and not checking that the Lottery and Gaming Credit carried over to your first bill.
Filing a low-income Wisconsin return without claiming the Homestead Credit, which renters can also claim.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.