Illinois State Tax Guide for Businesses & Individuals 2026
Illinois is the economic hub of the Midwest, home to a diverse range of industries including finance, manufacturing, agriculture, and technology, operating under a flat-rate income tax structure and a moderate statewide sales tax framework. Whether you are launching a new business entity or managing ongoing tax obligations across multiple Illinois jurisdictions, understanding the state's complete tax landscape is essential for maintaining full compliance in 2026. For a complete overview of US state tax requirements, visit our US Tax Compliance resource.
Quick Reference: Illinois Tax Rates at a Glance
| Tax Type | Rate / Detail |
|---|
| State Corporate Income Tax | 9.5% (7% income tax + 2.5% personal property replacement tax) |
| State Individual Income Tax | 4.95% flat rate on all Illinois taxable income |
| State Sales Tax Base Rate | 6.25% |
| Average Combined Sales Tax | ~8.86% (state + local taxes) |
| Unemployment Insurance (SUI/SUTA) | 0.725% – 7.625%; New employer: 3.525% |
| Effective Property Tax Rate | ~2.08% (avg. effective rate — among the highest in the US) |
| Estate / Inheritance Tax | Yes — Illinois estate tax applies to estates exceeding $4,000,000 |
Illinois Business Tax Nexus
What is Tax Nexus in Illinois?
Tax nexus in Illinois is the legal connection between a business and the state that creates an obligation to register, collect, file, and remit Illinois taxes. Nexus is established through physical presence within Illinois or through economic activity that meets defined thresholds under Illinois law.
Physical Nexus
- Maintaining an office, store, warehouse, distribution center, or any other fixed place of business in Illinois
- Employing workers, sales agents, or independent contractors who operate regularly within Illinois
- Storing inventory or goods in an Illinois facility, including Amazon FBA or third-party fulfillment centers
- Operating company-owned or leased vehicles within Illinois on a regular or systematic basis
- Owning, leasing, or using real or tangible personal property located within Illinois
Economic Nexus (Remote Sellers)
| Threshold Type | Requirement |
|---|
| Sales Threshold | $100,000 in gross receipts from sales delivered into Illinois in the prior 12 months |
| Transaction Count Threshold | 200 or more separate transactions delivered into Illinois in the prior 12 months |
| Effective Date | October 1, 2018 |
Click-Through & Affiliate Nexus
Illinois enforces both click-through and affiliate nexus rules. A remote seller establishes nexus in Illinois when it enters into an agreement with an Illinois resident who, for a commission or other consideration, refers customers via a website link or other means, and the seller's cumulative gross receipts from those referrals exceed $10,000 in the prior 12 months. Illinois also enforces marketplace facilitator nexus rules requiring platforms such as Amazon and eBay to collect and remit sales tax on behalf of third-party sellers.
Illinois State Income Tax
Corporate Income Tax
| Detail | Information |
|---|
| Corporate Income Tax Rate | 7.0% flat rate on Illinois net income |
| Personal Property Replacement Tax | 2.5% additional tax on net income for corporations (1.5% for partnerships, trusts, and S corporations) |
| Combined Effective Corporate Rate | 9.5% for C corporations |
| Apportionment Formula | Single sales factor (market-based sourcing) |
| Combined/Unitary Reporting | Mandatory combined reporting for unitary business groups operating in Illinois |
| Minimum Franchise Tax | Illinois franchise tax was phased out effective January 1, 2024; no minimum franchise tax applies for 2026 |
Individual Income Tax
| Illinois Taxable Income | Tax Rate |
|---|
| All taxable income (all filing statuses) | 4.95% flat rate |
| Deduction / Exemption | Amount |
|---|
| Standard Deduction | Illinois does not provide a standard deduction for individual filers |
| Personal Exemption (Single) | $2,425 per taxpayer |
| Personal Exemption (Married Filing Jointly) | $4,850 combined exemption for taxpayer and spouse |
| Dependent Exemption | $2,425 per qualifying dependent claimed on the return |
| Federal Tax Code Conformity | Rolling conformity — Illinois conforms to the current IRC with specific Illinois modifications including decoupling from certain federal bonus depreciation and QBID provisions |
Filing Deadlines
| Filing Type | Due Date |
|---|
| Corporate Return (Form IL-1120) | April 15, 2026 (calendar-year filers); 15th day of 4th month after fiscal year end |
| Individual Return (Form IL-1040) | April 15, 2026 |
| Extension Period | 6 months automatic extension; tax due in full by the original filing deadline |
| Estimated Payment Q1 | April 15, 2026 |
| Estimated Payment Q2 | June 15, 2026 |
| Estimated Payment Q3 | September 15, 2026 |
| Estimated Payment Q4 | December 15, 2026 |
Illinois Sales Tax
State Sales Tax Rate
Illinois imposes a statewide Retailers' Occupation Tax (sales tax) at a base rate of 6.25% on the retail sale of tangible personal property. Local jurisdictions — including counties, municipalities, and special taxing districts — may impose additional sales taxes, bringing the average combined rate to approximately 8.86% statewide. Chicago and Cook County have some of the highest combined sales tax rates in the nation.
Taxable vs. Exempt Goods & Services
| Category | Status | Notes |
|---|
| Tangible Personal Property | ✅ Taxable | All tangible goods sold at retail in Illinois are subject to the 6.25% state sales tax unless specifically exempted by statute |
| SaaS / Digital Products | ⚠️ Partial | Canned/prewritten software is taxable; SaaS delivered electronically without transfer of tangible personal property is generally not taxable in Illinois |
| Groceries / Food | ⚠️ Partial | Qualifying food for home consumption is taxed at a reduced 1% rate; prepared food and candy are taxed at the full 6.25% rate |
| Prescription Drugs | ❌ Exempt | Prescription medications and qualifying medical devices are fully exempt from Illinois sales tax |
| Clothing | ✅ Taxable | All clothing and apparel are subject to Illinois sales tax at the full 6.25% rate with no exemption threshold |
| Manufacturing Equipment | ❌ Exempt | Machinery and equipment used primarily in Illinois manufacturing or assembling processes qualify for a full sales tax exemption |
| Professional Services | ❌ Exempt | Most professional services are not subject to Illinois sales tax unless the service involves a transfer of tangible personal property |
Sales Tax Permits & Registration
- Registering Agency: Illinois Department of Revenue — www.revenue.illinois.gov
- Cost to Register: No fee — Illinois seller's permits (Certificate of Registration) are issued free of charge
- Renewal Requirement: No periodic renewal required; certificate remains valid unless the business closes or undergoes a significant ownership change
Filing Frequency & Deadlines
| Annual Tax Liability | Filing Frequency | Due Date |
|---|
| Less than $2,400 | Annual | January 20 of the following year |
| $2,400 – $19,999 | Quarterly | 20th day of the month following the quarter end |
| $20,000 or more | Monthly | 20th day of the following month |
Local Sales Tax Rates (Top Cities)
| Jurisdiction | Local Rate | Combined Rate |
|---|
| Chicago | 4.00% | 10.25% |
| Aurora | 2.25% | 8.50% |
| Rockford | 2.00% | 8.25% |
| Springfield | 2.75% | 9.00% |
| Naperville | 1.75% | 8.00% |
Illinois Payroll Tax & Compliance
Employer Payroll Tax Obligations
| Tax / Program | Rate / Detail |
|---|
| State Income Tax Withholding | 4.95% flat rate on all employee wages; withholding tables published by the Illinois Department of Revenue |
| SUI/SUTA Rate Range | 0.725% – 7.625% (employer paid) |
| SUI Taxable Wage Base | $13,590 per employee per year (2026) |
| New Employer SUI Rate | 3.525% for most new Illinois employers |
| Workers' Compensation | Private insurance required; Illinois does not operate a state workers' compensation fund |
| Paid Family & Medical Leave | Not applicable — Illinois does not have a state-mandated PFML program as of 2026 |
| State Disability Insurance | Not applicable — no separate Illinois SDI program exists |
Withholding Registration & Filing
- Registration Agency: Illinois Department of Revenue — www.revenue.illinois.gov
- Filing Frequency: Semi-weekly, monthly, or quarterly based on total annual withholding liability thresholds established by the Illinois Department of Revenue
- Annual Reconciliation Deadline: January 31 — Form IL-W-3 submitted with employee W-2 forms electronically to the Illinois Department of Revenue
- New Hire Reporting Deadline: Within 20 days of hire date to the Illinois Department of Employment Security New Hire Directory
Minimum Wage
| Category | Rate |
|---|
| Standard Minimum Wage | $15.00/hour (effective January 1, 2025; applicable statewide in 2026) |
| Tipped Employee Rate | $9.00/hour (60% of the standard minimum wage; tip credit applies) |
| Youth / Training Wage | $13.00/hour for employees under age 18 working fewer than 650 hours per year |
| Next Scheduled Increase | No additional automatic state increase currently scheduled beyond $15.00; subject to legislative action |
Illinois Property Tax
- Assessment Ratio: Varies by county — Cook County residential property assessed at 10% of fair market value; commercial property at 25%; other counties typically assess at 33.33% of fair market value
- Effective Average Rate: ~2.08% of fair market value statewide — one of the highest effective property tax rates in the United States
- Assessment Cycle: Annual reassessment in Cook County; triennial reassessment cycle in most other Illinois counties
- Appeal Deadline: Varies by county — Cook County appeals must be filed with the Cook County Assessor within 30 days of the assessment notice; other counties follow the county Board of Review schedule
Business Personal Property Tax
- Applicability: Illinois abolished the general business personal property tax in 1979; however, businesses pay the Personal Property Replacement Tax (PPRT) as part of the corporate income tax structure
- PPRT Rate: 2.5% for corporations; 1.5% for partnerships, trusts, and S corporations on net Illinois income
- Filing: Reported and paid through the standard Illinois corporate income tax return (Form IL-1120) or partnership return (Form IL-1065)
- Exemption Threshold: Not applicable — PPRT is calculated on net income rather than on the value of individual assets
Homestead & Other Exemptions
| Exemption Type | Amount / Rate | Eligibility |
|---|
| General Homestead Exemption | Up to $10,000 reduction in equalized assessed value (EAV) in Cook County; up to $6,000 in other counties | Owner-occupied primary residential property in Illinois; automatic in most counties after initial application |
| Senior Citizens Homestead Exemption | Up to $8,000 reduction in EAV in Cook County; up to $5,000 in other counties | Property owners age 65 or older occupying property as their primary Illinois residence |
| Senior Citizens Assessment Freeze | Freezes EAV at the base year level to prevent increases due to reassessment | Age 65 or older; household income at or below $65,000 annually; primary Illinois residence only |
| Disabled Veterans Exemption | Up to $100,000 reduction in EAV for qualifying disabled veterans | Veterans with service-connected disability of 30% or more; primary Illinois residence requirement applies |
Property Tax Due Dates
| Installment | Due Date | Notes |
|---|
| First Installment (Cook County) | March 1, 2026 | 55% of the prior year's total tax bill; no discount for early payment |
| Second Installment (Cook County) | August 1, 2026 | Remaining balance based on current year's assessed value and tax rates |
| Other Counties | Varies — typically June and September | Due dates set individually by each county collector; verify with your county treasurer |
Other Key Illinois Taxes
Franchise / Privilege Tax
Illinois eliminated its corporate franchise tax effective January 1, 2024. Corporations incorporated or qualified to do business in Illinois are no longer subject to an annual franchise tax on paid-in capital or net assets. All corporations are still required to file annual reports with the Illinois Secretary of State and pay the associated annual report fee of $75 for domestic corporations and $175 for foreign corporations.
Gross Receipts Tax
Illinois does not impose a general statewide gross receipts tax on businesses. Business income is taxed through the corporate income tax and personal property replacement tax framework. Certain utility and telecommunications providers are subject to sector-specific gross receipts assessments under Illinois utility tax statutes.
Excise Taxes
| Product | Rate |
|---|
| Gasoline | $0.47 per gallon (state motor fuel tax) |
| Diesel | $0.53 per gallon (state motor fuel tax) |
| Cigarettes | $2.98 per pack (20 cigarettes) |
| Beer | $0.231 per gallon |
| Wine | $1.39 per gallon (wine up to 20% alcohol content) |
| Cannabis | 10% – 25% based on THC content; additional 3% local cannabis retailer's occupation tax may apply |
Illinois Tax Credits & Incentives
| Credit / Incentive | Value / Rate | Eligibility |
|---|
| Illinois Research & Development Credit | 6.5% of qualifying Illinois R&D expenditures exceeding the base amount; 5-year carryforward available | Businesses conducting qualified research activities within Illinois against corporate income tax liability |
| EDGE Tax Credit (Economic Development for a Growing Economy) | Up to 100% of state income taxes withheld from net new employee wages for up to 10 years | Businesses creating qualifying net new jobs in Illinois that meet wage, benefit, and capital investment requirements |
| Invest in Kids Tax Credit | 75% of qualifying contributions to approved Scholarship Granting Organizations | Individual and corporate taxpayers making eligible contributions to approved Illinois scholarship programs |
| Historic Preservation Tax Credit | 25% of qualifying rehabilitation expenditures on certified Illinois historic structures | Property owners completing approved rehabilitation of structures on the Illinois or National Register of Historic Places |
| Angel Investment Tax Credit | 25% of qualifying investment in a qualified new business venture; maximum $2,000,000 credit per investor | Accredited investors providing equity financing to certified early-stage Illinois businesses |
| Manufacturing Machinery & Equipment Exemption Credit | Full exemption from Illinois sales and use tax on qualifying manufacturing equipment purchases | Illinois manufacturers purchasing machinery and equipment used primarily in qualifying production processes |
| Illinois Film Production Tax Credit | 30% of qualified Illinois production expenditures; additional 15% for salaries of Illinois residents employed on productions | Film, television, and commercial productions spending qualifying amounts on Illinois-based production activities |
How to Register a Business in Illinois
- Choose Your Business Structure: Select the appropriate entity type — LLC, Corporation, Partnership, or Sole Proprietorship — based on your liability, taxation, and operational requirements.
- Register with the Illinois Secretary of State: File Articles of Organization (LLC) or Articles of Incorporation (Corporation) at www.ilsos.gov. LLC filing fee: $150; Corporation filing fee: $150 minimum based on authorized shares.
- Obtain a Federal EIN: Apply for a free Employer Identification Number through the IRS at www.irs.gov — processed immediately online at no charge.
- Register for State Tax Accounts: Register for Illinois sales tax, withholding tax, and corporate income tax through the Illinois Department of Revenue MyTax Illinois portal at mytax.illinois.gov.
- Register for Unemployment Insurance: Establish an Illinois SUI employer account with the Illinois Department of Employment Security at www.ides.illinois.gov.
- Obtain Required Licenses and Permits: Review all applicable industry-specific licensing requirements through the Illinois Department of Financial and Professional Regulation and obtain any required local business permits from your city or county.
- Register for Local Business License: Contact your city or county government office to obtain any required local business operating licenses or zoning permits applicable to your business type and location.
Key Illinois Tax Agencies & Resources
| Agency | Responsibility | Website |
|---|
| Illinois Department of Revenue (IDOR) | Corporate income tax, individual income tax, sales tax, withholding tax, PPRT, tax registration and compliance | www.revenue.illinois.gov |
| Illinois Department of Employment Security (IDES) | Unemployment insurance, new hire reporting, wage and hour enforcement, workforce development | www.ides.illinois.gov |
| Illinois Secretary of State | Business entity registration, annual report filing, commercial recordings, registered agent requirements | www.ilsos.gov |
| Illinois Independent Tax Tribunal | Independent administrative review and appeals of Illinois Department of Revenue tax decisions | www.illinoistaxtribunal.gov |
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Note: This guide is for informational purposes only and does not constitute legal or tax advice. Consult a licensed tax professional for advice specific to your situation.
