WI
Wisconsin Small Business Tax Guide
Wisconsin sales, local and income tax figures in the Department of Revenue's published wording, each with its date. Educational only, not tax advice.
Disclaimer: This page is educational content only. Tax laws change, and your situation may differ. It is not legal, tax, or financial advice. Consult a qualified professional licensed in Wisconsin before making filing or planning decisions.
Tax landscape for small businesses
The Wisconsin Department of Revenue dates its guidance by the laws it reflects; its tax rates page covers "laws and regulations enacted as of January 16, 2026". Every Wisconsin figure below is quoted from a Department page with that date, or the date we checked it, beside it. Before you file, check the figures with the Department or ask a tax professional.
On sales tax, the Department (Wisconsin, DOR guidance on laws enacted as of January 16, 2026) says: "The Wisconsin sales tax is a 5% tax imposed on the sales price of retailers who sell, license, lease, or rent tangible personal property, certain coins and stamps, certain leased property affixed to realty, or certain digital goods, or sell, license, perform, or furnish taxable services in Wisconsin." For local taxes it says: "Seventy Wisconsin counties have adopted a 0.5% county tax." It adds: "The city of Milwaukee is the only municipality that imposes a city sales and use tax."
For sellers based outside the state, the Department (Wisconsin, DOR remote-seller guidance on laws enacted as of February 10, 2026) says "a remote seller is only required to collect and remit sales or use tax if its gross sales into Wisconsin exceed $100,000 in the previous or current calendar year."
Worked example, with sample figures: a $600.00 taxable sale in a county with the 0.5% county tax (not Milwaukee County, which the Department lists at 0.9%, and outside the city of Milwaukee and its 2% city tax). At the 5% state rate and the 0.5% county rate quoted above (Wisconsin, DOR guidance on laws enacted as of January 16, 2026), state tax is $600.00 × 5% = $30.00 and county tax is $600.00 × 0.5% = $3.00, so the invoice comes to $633.00. For the rate at a given address, the Department (Wisconsin, checked October 31, 2026) says: "Use the Sales Tax Rate Lookup to determine the tax rate that applies to a specific street address or 9-digit zip code." Use your own figures; these are only an illustration.
Billed's invoice software page says: "Save your tax rates and settings once, and Billed calculates taxes automatically when you create invoices and estimates."
Tax overview
Each row lists a tax area and its notes. Confirm current figures with your state's tax agency or the IRS.
| Tax type | Rate or basis | Notes |
|---|---|---|
| State sales and use tax | "a 5% tax" | Department of Revenue (Wisconsin, DOR guidance on laws enacted as of January 16, 2026): "The Wisconsin sales tax is a 5% tax imposed on the sales price of retailers who sell, license, lease, or rent tangible personal property, certain coins and stamps, certain leased property affixed to realty, or certain digital goods, or sell, license, perform, or furnish taxable services in Wisconsin." |
| County sales and use tax | "a 0.5% county tax" (Milwaukee County "0.9%") | (Wisconsin, DOR guidance on laws enacted as of January 16, 2026): "Seventy Wisconsin counties have adopted a 0.5% county tax. Milwaukee County sales and use tax increases from 0.5% to 0.9%, effective January 1, 2024." |
| City of Milwaukee sales and use tax | "2%" | (Wisconsin, DOR guidance on laws enacted as of January 16, 2026): "The 2% city of Milwaukee sales and use tax is effective January 1, 2024." |
| Individual income tax | "3.50% to 7.65%" | (Wisconsin, DOR guidance on laws enacted as of January 16, 2026): "Wisconsin individual income tax rates vary from 3.50% to 7.65%, depending upon marital status and income." |
| Federal self-employment tax | "15.3%" | In the US (federal), the IRS self-employment tax page (updated October 30, 2026): "The self-employment tax rate is 15.3%." |
Filing requirements
This list isn't a complete checklist for your business.
Register your business
The Department's new business page (Wisconsin, checked October 31, 2026) points to One Stop Business Registration to "register your business with multiple agencies, including the Department of Financial Institutions and the Department of Workforce Development."
Remote sellers
The Department (Wisconsin, DOR remote-seller guidance on laws enacted as of February 10, 2026) says "a remote seller is only required to collect and remit sales or use tax if its gross sales into Wisconsin exceed $100,000 in the previous or current calendar year."
Federal estimated tax
In the US (federal), the IRS estimated taxes page (updated September 25, 2026) says: "Individuals, including sole proprietors, partners, and S corporation shareholders, generally have to make estimated tax payments if they expect to owe tax of $1,000 or more when their return is filed."
Deductions and write-offs
Confirm with your state how it treats each item.
- Exemption certificates: the Department's sales and use tax exemptions guidance (Wisconsin, DOR guidance on laws enacted as of January 20, 2026) says: "Normally, to purchase taxable products or services in Wisconsin without tax, an exemption certificate must be given to the seller." It adds: "Exemption certificates are signed by purchasers and are given to sellers to verify that a transaction is exempt." and "Sellers must retain copies of the exemption certificates."
- SE tax, employer half: In the US (federal), the IRS self-employment tax page (updated October 30, 2026) says: "You can deduct the employer-equivalent portion of your self-employment tax in figuring your adjusted gross income." How Wisconsin treats it is for the Department of Revenue or a tax professional to confirm.
- Proof of costs: In the US (federal), the IRS recordkeeping page (updated May 1, 2026) says: "You must be able to prove certain elements of expenses to deduct them."
Practical tips
- Before invoicing a taxable sale, look up the rate in the Department's Sales Tax Rate Lookup (Wisconsin, checked October 31, 2026), ask the Department which address applies to the sale if you aren't sure, and file the result with the invoice.
- In a county that has adopted the county tax (Wisconsin, DOR guidance on laws enacted as of January 16, 2026), put it on its own line below the state tax.
- If you sell into Wisconsin from another state, track your yearly sales into the state against the Department's threshold (Wisconsin, DOR remote-seller guidance on laws enacted as of February 10, 2026).
- Note each Department page you rely on and the date it shows, and check it again before the next filing.
Frequently asked questions
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At a glance
| Topic | Official source | Date shown |
|---|---|---|
| Sales, county, city and income tax rates | Wisconsin Department of Revenue, tax rates page | Laws enacted as of January 16, 2026 |
| Remote sellers | Wisconsin Department of Revenue, remote sellers page | Laws enacted as of February 10, 2026 |
| Exemption certificates | Wisconsin Department of Revenue, sales and use tax exemptions page | Laws enacted as of January 20, 2026 |
| Registration and rate lookup | Wisconsin Department of Revenue | Checked October 31, 2026 |
| Federal self-employment and estimated tax | IRS.gov | Updated October 30 and September 25, 2026 |
When this isn't for you
This guide doesn't cover Wisconsin corporate franchise tax, payroll, property tax or industry-specific taxes. For those, and for your own filings, contact the Wisconsin Department of Revenue or a tax professional.