Filing your Illinois state income tax return for 2017 requires a clear understanding of the tax act and how your federal income tax return figures into state calculations. Your federal adjusted gross income determines your Illinois base income, which is taxed at a uniform tax rate of 4.3549%—unless you elect the split-rate method under Public Act 100-0022. To avoid estimated payment penalties and interest on unpaid tax, you must meet the deadline for filing your income tax by April 17, 2018, and accurately report your exemption claimed figures.
Whether you’re a full-year resident, part-year resident, or nonresident, you will use Form IL-1040 to report income from jobs, self-employment, or limited liability company activities. Operators under the Service Occupation Tax Act, Retailers Occupation Tax Act, Hotel Operators Occupation Tax Act, and Transportation Network Providers Act—including private party vehicle drivers—must include those amounts on their return. If you purchased motor vehicles or sold tobacco products, review the Illinois vehicle code and definition of tobacco products to determine which amounts to exclude or include. Use Schedule NR and the Use Tax Act to prevent double taxation.
This guide will walk you through setting up or logging into your MyTax Illinois account, requesting an electronic filing exception, using revenue walk-up windows if needed, and choosing between credit card payments, ACH, or only check payments with Form IL-1040-V. You will learn how to apply the rolling stock exemption, when to request an identity verification letter or contact the informal conference board, and how to address notices from IDOR’s audit bureau. By following each section, you will minimize penalties, manage current tax year liabilities, and ensure your return satisfies all Illinois Department requirements.
Determining whether you must file an Illinois return starts with your residency status and income levels. Filing your federal income tax return first is essential because your Illinois base income is calculated based on your federal adjusted gross income.
The deadline for filing income tax for the 2017 tax year was April 17, 2018. The usual April 15 deadline was extended due to the Emancipation Day holiday in Washington, D.C. Late filings incur estimated payment penalties and interest on unpaid tax, so marking this date in your calendar—whether you use the in-person counter service or e-file—is critical to minimizing fees.
Illinois allows certain credits and exemptions only up to specific income caps. Knowing these thresholds helps you plan deductions and claim benefits.
Public Act 100-0022 raised Illinois' income tax rate in 2017.
Illinois expanded several credits to provide additional relief in 2017.
Several targeted relief provisions and limitations took effect.
Begin by collecting every document that supports your Illinois filing under the Illinois Income Tax Act. You will need your federal income tax return (Form 1040) or, if you’re not required to file federally, a completed 1040 worksheet. In addition, gather all W-2s, 1099s (such as 1099-INT, 1099-DIV, and 1099-R), Schedule K-1s, and records of self-employment income from a limited liability company or private party vehicle operations. Keep receipts for property taxes, educational expenses, and other deductions to substantiate credits like the K-12 Education Expense Credit.
Illinois calculates base income from your federal adjusted gross income, so complete your federal return before starting Form IL-1040. Suppose you qualify for an electronic filing exception because of low income or disability. In that case, you can still file electronically via your MyTax Illinois account or use the revenue walk-up windows at IDOR offices. Confirm your federal AGI and exemption claimed amounts to ensure your income tax filing deadline calculations align with state requirements.
Form IL-1040 consolidates your income, credits, and payments in one place.
Certain taxpayers face unique rules under specific tax acts.
By following these streamlined steps—gathering documents, completing your federal return first, accurately filling out forms, and addressing special situations—you will meet the Illinois income tax filing deadline with confidence and
Create or log in to your MyTax Illinois account to file free of charge. E-filing offers immediate acceptance confirmation, built-in error checks, and typically faster refunds compared to paper returns.
If you choose to file by paper, mail your completed return to the appropriate address:
Illinois Department of Revenue
Springfield, IL 62726-0001
Illinois Department of Revenue
Springfield, IL 62719-0001
Using the correct address ensures that your return and any credit card payments or checks arrive at the proper processing center. If you’re sending a check or money order, include Form IL-1040-V.
Tax payments were due April 17, 2018. Late payments trigger estimated penalties and interest on any balance owing, so use ACH or credit card options to meet deadlines.
Before sending your return, confirm you have:
Ensure all lines on Form IL-1040 match your federal income tax return figures to prevent discrepancies with the Illinois Department. Reviewing your exemption claim and uniform tax rate calculations helps minimize penalties and avoid triggering IDOR’s audit bureau.
Include W-2s, 1099s, and Schedules NR, CR, IL-EIC, ICR, M, SA, and G as applicable. Proper attachments support credits under the service tax and use tax acts, reducing current tax year liabilities.
You can choose between ACH via your MyTax Illinois account, credit card payments, or only check payments with Form IL-1040-V. Timely payment by the income tax deadline prevents estimated payment penalties and interest on unpaid tax.
Mail your return to the designated IDOR processing center based on whether you’re enclosing payment to ensure it reaches the correct department immediately.
Sign Form IL-1040 (and your spouse if filing jointly) to validate your submission. Retain copies of your return, payment vouchers, and all supporting documents for at least four years in case of inquiries by IDOR’s informal conference board.
If you report Schedule C income on your federal return, include it on Form IL-1040 and consider quarterly estimated payments to avoid underpayment penalties.
If you missed the April 17, 2018, income tax filing deadline, file your return immediately to limit penalties. Illinois charges estimated payment penalties and interest on any balance due since the original due date. If you are owed a refund, there is no late‐filing penalty, but you must file within three years of April 17, 2018, to claim it and avoid forfeiting your refund.
You can e-file your 2017 Illinois return for free through your MyTax Illinois account. Electronic filing offers immediate receipt confirmation, built-in error checks, and usually faster refunds than paper filing. Whether you report income from private party vehicles or claim credits under the Income Tax Act, e-filing reduces mistakes and gives you online access to payment history and current tax year liabilities.
Taxpayers often overlook the K-12 Education Expense Credit, which covers up to $750 per family, and the enhanced Illinois Earned Income Credit at 14% of your federal EIC. Other frequently missed benefits include the Property Tax Credit, Credit for Taxes Paid to Other States (Schedule CR), and the new Instructional Materials and Supplies Credit. Reviewing these can significantly reduce your current tax year liabilities.
Illinois automatically grants a six-month filing extension, so you don’t need to file IL-505-I to extend the deadline. However, any tax owed for 2017 remained due by April 17, 2018, to avoid estimated payment penalties and interest. Use your MyTax Illinois account or IL-1040-V with a check or credit card payment to submit owed balances by the original filing deadline.
Yes, married couples who lived together at any point during 2017 can file jointly on Form IL-1040. Part-year residents must use Schedule NR to divide income between Illinois and other states based on residency dates. Accurately allocating income ensures you only pay Illinois tax on income earned while a resident, while reciprocal-state rules may apply for work in neighboring states.
Illinois has reciprocal agreements with Iowa, Kentucky, Michigan, and Wisconsin. If you live in one of those states but work in Illinois, you file IL-1040 and Schedule NR, report your Illinois wages as base income, but owe no withholding to your home state. Conversely, Illinois residents in those states report income on IL-1040 but avoid duplicate withholding, streamlining their tax filing process.
If you paid tax on income to other states, use Schedule CR to claim a credit for taxes paid to other states, preventing double taxation. You will need copies of the different states’ returns, proof of tax payments, and your federal income figures. Correctly completing Schedule CR reduces your total Illinois tax owed and helps you comply with the Retail Occupation Tax Act and Use Tax Act, where applicable.
Agenda hoy tu revisión gratuita y confidencial de alivio fiscal.
© 2025 Get Tax Relief Now. Expertos confiables en alivio fiscal federal y estatal. Todos los derechos reservados.
