Illinois Income Taxes and State Tax Forms
"The Prairie State"
Start Federal and Illinois State Tax Returns
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Prepare and efile Your Illinois State Tax Return
With the efile.com online tax software, it is easy for you to prepare and efile your Illinois state tax return and federal tax return together or separately (view the federal tax return filing requirements). The efile software helps you choose all the right state and federal forms, and you can prepare and efile as many state returns (resident, nonresident, or part-year resident) as you need for one price.
Illinois Income Tax Filing Deadlines
The regular deadline to file an Illinois state income tax return is April 15.
|Tax Deadline Date
||Type of Income Tax Return
||Filing Deadline / Due Date Description
|April 17, 2018
||2017 Illinois State Tax Return
||Due date for Illinois State Income Tax Returns - income tax filing deadline
|April 17, 2018
||2017 Illinois State Tax Extension
||Due date for Illinois automatic extensions (and payment due date if tax is owed)
|October 15, 2018
||2017 Illinois State Tax Return
||Last day to efile a 2017 Illinois State Income Tax Return for tax extension filers and late efilers
View all state tax return filing deadlines here.
Find federal income tax return filing deadlines here.
Tax Year 2017 Illinois State Tax Forms
All of the following Illinois state tax forms are supported by the efile.com software:
||Can I efile this form?
||Individual Income Tax Return
||Estimated Income Tax Payments for Individuals
||Payment Voucher for Individual Income Tax
||Refund Due a Deceased Taxpayer
||Computation of Penalties for Individuals
||Gains from Sales of Employer's Securities Received from a Qualified Employee Benefit Plan
||Substitute for Unobtainable Form W-2
||Income Tax Subtractions & Credits for Individuals
|Schedule 1299-C (R&D)
||Research and Development Credit Supplemental Schedule for Individuals
||Recapture of Investment Tax Credits
||Tax Paid to Other States Credit
||Gains from Sales or Exchanges of Property Acquired Before August 1, 1969
||Voluntary Charitable Donations
||Other Additions and Subtractions
||Nonresident & Part-Year Resident Computation
||Specific Accounting Method of Computing Net Income for Individuals
Illinois State Tax Forms That Cannot Be efiled
Illinois Tax Withholding Form
||Illinois State Employees Withholding Allowance Certificate
IL Tax Extension
||Illinois Extension Instructions
||How to File
Illinois grants an automatic six-month extension of time to file your state tax return. You do not have to file any form with Illinois to take advantage of the extension. The extended filing deadline is October 15, 2018.
If you received an extension of more than six months to file your federal tax return, you are automatically allowed to receive the same extension of time to file your IL state return.
The IL state tax extension is an extension of time to file, not to pay. If you owe state tax, you must also make a payment using Form IL-505-I, Automatic Extension Payment for Individuals, by April 17, 2018.
You can also pay online with the Illinois Department of Revenue's agency website. After April 17, 2018, you will begin to owe penalties and interest on any unpaid taxes.
Automatic extension granted
IL Tax Amendment
Amended Illinois state tax returns can only be filed by mail; they cannot be efiled. Learn how to prepare and file an Illinois tax amendment.
2016 Past Year IL Tax Forms
Illinois tax returns for 2016 and other past tax years cannot be prepared and filed online. Download, fill out, and mail your 2016 IL return to the Illinois Department of Revenue.
Where's My Refund? - Check Your IL State Tax Refund Status
Using efile and direct deposit is the fastest way to get your Illinois state tax refund. If you efile an Illinois state tax return, your refund will generally be processed within 1 week. If you file a paper return, it could take as long as 15 weeks to receive your state refund.
Check your Illinois tax refund status.
IL efile Error Codes
View a list of all Illinois State efile Income Tax Return Error Reject Codes.
Illinois Tax Facts
IL Income Tax:
Illinois taxes individual income at a single flat rate of 3.75%
IL Sales Tax:
The state of Illinois levies a 6.25% sales tax on most goods. The rate is 1% for certain food items, medicines, and medical items. Local governments levy additional sales taxes at various rates. Some things, like newspapers, and some large items (such as machinery used for farming or for the graphic arts) are exempt from sales tax.
More information on Illinois sales tax
IL Personal Property Tax:
In Illinois, real estate is taxed locally at different rates by several taxing districts, including municipalities, counties, townships, school districts, and special districts.
Odd Tax Fact:
To cash in on tourists, the city of Chicago taxes transportation, including taxis and trolleys.
State Tax Agency:
For more information, you can visit the website of the Illinois Department of Revenue.
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