Get your tax IDs in Wisconsin

An EIN, if you need one, takes minutes online. Wisconsin then adds a seller’s permit if you make taxable retail sales, income tax for the people and companies that have to file, withholding once you pay taxable wages, and unemployment tax once you are a liable employer.

What’s different in Wisconsin

• The state sales tax is 5%, and most counties add 0.5%¹. Milwaukee County and the city of Milwaukee are higher. The first permit carries a $20⁴ registration fee, and the department may ask for a security deposit.
• The 2026 rate schedule and the tax-rates page do not print the same dollar brackets. The tax-rates page shows the 2025 brackets. The 2026 estimated-tax instructions show the 2026 ones. Use the schedule for the year you are filing.
• A C corporation and an S corporation do not share a due month. The corporation page gives a C corporation the 4th month. The Form 5S instructions give an S corporation the 3rd month.
• The economic development surcharge is not due at formation. It applies to corporations, insurance companies, certain exempt organizations, and tax-option (S) corporations with at least 4 million dollars of gross receipts¹⁴.
• A new employer’s unemployment rate depends on payroll. The rate schedule prints a higher pair of new-employer rates at $500,000¹⁹ of payroll or more. The employer report prints only the lower pair.

Do this

1. Get an EIN from the IRS if you need one. It is free and, if approved, issued immediately²⁴ online. You will need it to hire, to open many bank accounts, and to file unemployment and new-hire reports. A sole proprietor with no employees can often use a Social Security number for federal tax. Don’t pay a website to apply for you.
2. If you will make taxable retail sales, apply for a seller’s permit through Wisconsin DOR business registration. If One Stop already opened the same tax account for you, verify it before applying again. The permit is required for every person or organization with a Wisconsin sales location that makes retail sales of taxable products, unless every sale is exempt. It is not required for a wholesaler or manufacturer that does not sell taxable products in Wisconsin, or for a marketplace seller whose marketplace provider collects and remits the tax. Apply at least three weeks before you open. A permit from a business you buy does not transfer. Online, the number arrives in one to two business days by email if you register online, and the paper permit follows in seven to ten business days. The permit has to be displayed at the place of business, or carried to temporary locations if the business has no fixed one. Publication 201 sets a business tax registration fee of $20 on the first permit or certificate only. It covers two years, then renews for $10⁴. The department may also require a security deposit of up to $15,000². If you are asked for one and you do not pay it, the department may refuse the permit or revoke it.
3. Collect the rate for the place where the sale is sourced. The state rate is 5%. Seventy Wisconsin counties have adopted 0.5%. Milwaukee County is 0.9%, effective January 1, 2024. The city of Milwaukee is the only city tax on that page, at 2%¹, also effective January 1, 2024. Use the rate lookup for the address. The reporting period is monthly, quarterly, or annually, as the department assigns. A return is due the last day of the month after the reporting period, except an early monthly filer, who files by the 20th of the following month. Publication 201 ties that earlier date to tax of more than $3,600⁴ a quarter, and the department tells you in writing. If you pay by ACH debit, the state’s electronic payment rule says to start the debit before 4:00 p.m. Central time on the last business day before the due date⁵, so the payment settles by the due date. The department’s sales tax questions page gives a later cutoff, 4:00 p.m. Central time on the due date³. An annual sales return is due January 31 for a calendar-year annual filer; for a fiscal-year annual filer, the deadline is the last day of the month after the fiscal year ends⁹. A weekend or holiday moves the due date to the next business day. File through My Tax Account for every assigned period, even when the tax is zero.
4. If you are a person who has to file, use the brackets for the year you are filing. The 2026 estimated-tax instructions tax full-year residents at 3.5%, then 4.4%, then 5.3%, then 7.65%. For a single filer, head of household, an estate, or a trust, the first bracket runs through $15,110, the next through $51,950, and the next through $332,720. A joint return uses $20,150, $69,260, and $443,630. Married filing separately starts at $10,080 and reaches the top rate after $221,820. Nonresidents and part-year residents prorate those brackets. The department’s tax-rates page shows the 2025 brackets, where the lowest rate ends at $14,680 for a single filer and $19,580¹ on a joint return. Pay estimated tax for 2026 if you expect to owe at least $500 after withholding and credits. The installments on that form are April 15, 2026, June 15, 2026, September 15, 2026, and January 15, 2027⁶. Publication 401 states the general rule: the filing deadline is April 15, 2027 for a 2026 calendar-year return, subject to the corresponding federal filing-date and extension rules⁸. The older deadline FAQ still lists April 15, 2026, for the 2025 return. A late file without an extension can cost $50. The extension is a 180-day extension, the same length as the federal extension. During an extension, interest is 1%⁷ a month on the unpaid tax. This page does not compute the tax.
5. If you will pay wages, register for withholding with Wisconsin DOR. You have to withhold if you are an employer who pays wages to a Wisconsin resident, or to a nonresident for work performed in Wisconsin, and who is engaged in business, licensed, organized, or transacting business in Wisconsin. The exceptions include reciprocity with Illinois, Indiana, Kentucky, and Michigan, and a nonresident whose Wisconsin earnings are expected to stay under $2,000. Every employer that has to withhold must register with the Department of Revenue for a withholding account number. The annual reconciliation, Form WT-7, is due January 31. A monthly or quarterly deposit report is due the last day of the month after the month or the quarter¹¹. The department assigns your filing frequency from your application. The withholding guide explains each one. The hiring guide covers the federal side.
6. If the business is taxed as a C corporation, calendar the franchise or income tax. The rate is 7.9%. Only one of the two taxes is imposed in a year. The return is due the 15th day of the 4th month after the taxable year ends. A federal filing extension moves the Wisconsin due date to 30 days after the federal extended due date. Without a federal extension, Wisconsin law gives an automatic extension of 7 months, or until the original federal due date, whichever is later. Estimated payments start when the tax plus the economic development surcharge is expected to be $500¹³ or more. The surcharge applies to corporations, insurance companies, certain exempt organizations, and tax-option (S) corporations with at least 4 million dollars of gross receipts. For a C corporation it is the greater of $25 or 3% of the Wisconsin gross tax, and not more than $9,800¹⁴.
7. If you elected S status, file Form 5S. The instructions say the return is due the 15th day of the 3rd month after the taxable year ends. Form 5S has to be filed electronically unless the department grants a hardship waiver. A federal extension moves the Wisconsin due date to 30 days after the federal extended due date. An extension to file does not extend the time to pay: interest runs on tax not paid by the 15th day of the 3rd month after the taxable year ends. A return filed after the extension costs $150¹⁵. Those sentences are from the tax year 2025 instructions, the latest Form 5S instructions on the site when this page was checked.* For an S corporation in that group, the surcharge is the greater of $25 or 0.2% of Wisconsin net income, and not more than $9,800¹⁴. The election is federal, on Form 2553²⁵. This page does not pick it.
8. If the business is a partnership or an LLC taxed as a partnership, match the return to the federal classification. A single-member LLC that is disregarded files the way its owner files. A partnership can elect to pay tax at the entity. The 2025 Schedule 3-ET instructions tax that income at 7.9%¹⁷. A 2026 Schedule 3-ET was not posted when this page was checked.* The election needs the consent of partners who hold more than 50 percent of the capital and profits on the day of the election. It is made each year, on or before the extended due date of Form 3, by checking a box on that return. An extension to file does not extend the time to pay: interest runs on tax not paid by the 15th day of the 3rd month after the taxable year ends. A Wisconsin-only extension runs up to six months. A federal extension moves the Wisconsin due date to the federal extended due date¹⁶. Unlike the corporation rule, it does not add 30 days.
9. Register for unemployment tax in the DWD Employer Portal when you become a liable employer. One test is $1,500 in any calendar quarter of the current or preceding year. Another is one person in each of 20 or more weeks in Wisconsin in the current or preceding year. Federal unemployment tax on the whole payroll, and buying a business that is already covered, are separate tests on the same report. Agricultural labor is outside the usual test unless the farm paid 20,000 dollars of cash wages in a quarter, or 10 workers in 20 weeks, for agricultural labor. For 2026 the wage base is $14,000, and the rates come from Schedule D for 2026. A new employer pays 3.05%, or 2.5% in construction, when its payroll is under $500,000. At $500,000 or more, the rate schedule prints 3.25%, or 2.7%¹⁹ in construction. The statute sets the solvency part of the rate by payroll, counted over the 12 months ending with the computation date before the year the rate applies²⁰. Due dates for a new employer depend on when liability starts. The latest date the report prints for 2026 tax is January 31, 2027¹⁸. Once you are set up, the employer handbook lists quarterly reports as due April 30, July 31, October 31, and January 31, the end of the month after each quarter²¹.
10. Report new hires through Wisconsin’s New Hire Reporting Center. In Wisconsin, an employer with an EIN has to report each new hire within 20 days. The same report covers a rehire, a recall, or a return to work after more than 60 days unpaid²³.

What you get back

An EIN from the IRS if you applied, a seller’s permit if you registered and the department issued one, a withholding account number once you are required to withhold, and an unemployment account once the department sets one up. Local licenses are on Licenses and permits.