The Small Business Owner’s Complete Guide to Payroll Compliance in Illinois and Wisconsin
Payroll compliance isn’t optional — and in Illinois and Wisconsin, the rules are specific, the deadlines are real, and the penalties for getting it wrong add up fast. This guide covers what every small business owner in these states needs to know.
Federal payroll compliance — the foundation
Before we get to state-specific requirements, let’s establish the federal baseline that applies to all employers regardless of state:
Federal tax withholding and deposits
Every employer must withhold federal income tax, Social Security (6.2%), and Medicare (1.45%) from employee wages. The employer matches the Social Security and Medicare contributions. These amounts, plus the employer’s share, must be deposited with the IRS on a schedule based on your deposit history:
- Monthly depositors: New employers and those whose payroll tax liability was under $50,000 in the lookback period deposit by the 15th of the following month
- Semi-weekly depositors: Businesses with higher tax liability deposit within 3 business days of payroll (Wednesday/Friday cutoffs)
- Next-day depositors: Any single payroll that generates $100,000+ in tax liability must be deposited the next business day
Federal payroll tax filings
- Form 941 (Employer’s Quarterly Federal Tax Return) — due April 30, July 31, October 31, January 31
- Form 940 (Federal Unemployment Tax) — annual, due January 31
- W-2s — must be provided to employees by January 31; filed with SSA by January 31
- Form 1099-NEC — for contractors paid $600+; due January 31
New hire reporting
Federal law requires employers to report all new hires to the state directory of new hires within 20 days of the hire date. Both Illinois and Wisconsin have their own online portals for this.
Illinois payroll compliance
Illinois income tax withholding
Illinois has a flat income tax rate of 4.95% (as of 2025) that employers must withhold from employee wages. The withholding schedule mirrors the federal deposit schedule — if you’re a semi-weekly federal depositor, you’re a semi-weekly Illinois depositor too.
Illinois unemployment insurance (UI)
Illinois employers pay state unemployment tax (SUTA) on the first $13,590 of each employee’s wages (2025 wage base — confirm current year). New employer rates typically start around 3.175%, but rates adjust annually based on your claims experience.
Illinois minimum wage
Illinois has been incrementally increasing its minimum wage. Verify the current rate at Illinois.gov — it has changed annually in recent years. The tipped minimum wage in Illinois is different from the standard minimum wage, and tip credit rules apply.
Illinois new hire reporting
Illinois employers must report new hires and rehires within 20 days of the hire date through the Illinois Department of Employment Security (IDES) online portal. Failure to report on time can result in penalties up to $500 per unreported hire when there’s a conspiracy to avoid reporting.
Illinois paycheck requirements
Illinois law requires employers to pay employees at least semi-monthly (twice per month). Weekly payroll also complies. Employers must provide employees with a written or electronic pay stub showing gross wages, deductions, and net pay.
Illinois One Day Rest in Seven Act
Illinois employers must provide employees with at least 24 consecutive hours of rest in every seven-day period. This is a compliance requirement many small business owners overlook — particularly in industries like restaurants and retail where seven-day schedules are common.
Wisconsin payroll compliance
Wisconsin income tax withholding
Wisconsin has a graduated income tax with multiple brackets (3.54%–7.65% as of 2025). Withholding is based on employee W-4 elections and Wisconsin-specific withholding tables published by the Wisconsin Department of Revenue (DOR).
Wisconsin unemployment insurance
Wisconsin SUTA is paid on the first $14,000 of each employee’s wages (2025 wage base — verify current year). New employer rates vary by industry. Rates adjust annually based on your claims experience and the overall health of the Wisconsin UI Trust Fund.
Wisconsin minimum wage
Wisconsin’s minimum wage has been $7.25/hour (the federal floor) for many years, but verify the current rate as legislation can change. Wisconsin also has a lower tipped minimum wage — currently $2.33/hour — though employers must make up the difference if tips don’t bring an employee to minimum wage.
Wisconsin new hire reporting
Wisconsin employers must report new hires within 20 days through the Wisconsin New Hire Reporting Center. Reports can be submitted online, by mail, or by fax. Penalties apply for failure to report.
Wisconsin paycheck requirements
Wisconsin law requires employers to pay employees at least monthly (though more frequent is fine). Employers must pay all wages earned at the time of separation — Wisconsin does not allow employers to withhold a final paycheck for any reason.
Wisconsin’s final paycheck law
Wisconsin has specific rules about final paychecks. Employees who are discharged must be paid on the next regular payday or within one month, whichever is earlier. Employees who resign must be paid on the next regular payday. Violations can result in employees being entitled to double damages.
The payroll compliance calendar
Plus: Payroll tax deposits on your federal schedule (monthly or semi-weekly), Illinois and Wisconsin withholding deposits on matching schedules, and new hire reporting within 20 days of each hire.
Don’t track this yourself. When you work with a full-service payroll provider like Payroll Freedom, we handle every deposit and filing on your behalf — federal and state. You never have to track a deadline or risk a late penalty because we missed something. That’s the whole point.
The most common compliance mistakes small businesses make
- Missing payroll tax deposit deadlines — even by one day triggers penalties
- Using the wrong deposit schedule (monthly vs. semi-weekly)
- Forgetting to report new hires within the 20-day window
- Incorrectly classifying employees as independent contractors
- Not updating withholding when employees submit new W-4s
- Missing the January 31 W-2 and 941 deadlines
- Not staying current on minimum wage changes (especially Illinois)
Let us handle every deadline — so you don’t have to.
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