Indiana’s main individual income tax form is Form IT-40, which full-year residents use to report income and calculate what they owe at the state’s flat 2.95% rate for 2026.1Indiana Department of Revenue. Rates Fees and Penalties Part-year residents and nonresidents with Indiana-source income file Form IT-40PNR instead. Both returns carry a county tax schedule, and a short Form SC-40 exists for very low-income seniors. Picking the right one is the first decision, and the rest of the Indiana state tax forms you need follow from it.
Which Form You File
Indiana Code 6-3-1-12 treats you as a resident if you were domiciled in Indiana during the tax year, or if you kept a permanent residence here and spent more than 183 days in the state.2Indiana General Assembly. Indiana Code Title 6 Taxation 6-3-1-12 If either test fits you for the whole year, you file Form IT-40. It reports all your income from every source, including money earned outside Indiana.
If you lived in Indiana for only part of the year, or lived elsewhere but earned Indiana-source income, Form IT-40PNR is the correct return. It apportions your income so you’re taxed only on the Indiana share. Filing the wrong form won’t create legal trouble on its own, but it can trigger processing delays or an incorrect bill that takes months to sort out.
Form SC-40 is a shorter one-page return available to very low-income seniors. Single filers age 65 or older with less than $2,500 in income, or married couples where both spouses are 65 or older with less than $5,000 in income, can use it in place of the full IT-40.
Where to Get the Forms
All forms and the schedules that go with them are available on the Indiana Department of Revenue website, and paper copies can be picked up at a regional district office. Most filers submit electronically through the state’s INTIME portal rather than printing anything.
The County Tax Schedule You Can’t Skip
One thing that surprises newcomers: nearly every Indiana county charges its own income tax on top of the state rate. County rates range from roughly 1% to over 2.75% depending on where you live.3National Finance Center. Indiana Counties (Local) Income Tax Withholding In a county at 2%, the combined rate approaches 5%.
Your county tax is based on where you lived on January 1 of the tax year, not where you live when you file. If you moved counties later in the year, you still owe tax to your January 1 county for the full year, and the new county only takes over for the next tax year.4Indiana Department of Revenue. General Information on Local Income Taxes Full-year residents report county tax on Schedule CT-40, attached to Form IT-40; part-year residents and nonresidents use Schedule CT-40PNR. The math is straightforward: Indiana taxable income multiplied by your county’s rate.
Deadline and Extensions
Indiana returns are due April 15, 2026, the same day as the federal deadline.5Indiana Department of Revenue. Extension of Time to File If you can’t make that date, you have two routes to an extension. If you already filed federal Form 4868, Indiana automatically grants the federal extension plus one additional month. Attach a copy of the federal extension when you file your state return.6Indiana Department of Revenue. Instruction for Obtaining Extensions of Time to File Indiana Individual Income Tax Returns
Without a federal extension, you can request a state extension through INTIME or by filing Form IT-9 on or before April 15. Either way, an extension buys you time to file, not time to pay. You need to pay at least 90% of your combined state and county tax by April 15 to avoid penalties, and interest runs on any unpaid balance starting the day after the deadline.5Indiana Department of Revenue. Extension of Time to File
Late-filing penalties are $10 per day up to $250, and a separate late-payment penalty of 10% of the unpaid tax (or $5, whichever is greater) applies if you don’t pay on time.7Indiana Department of Revenue. Fines, Fees and Penalties They stack.
Deductions, Credits, and Exemptions
Indiana adjusted gross income starts with federal adjusted gross income from your 1040 and then applies state-specific modifications.8Indiana General Assembly. Indiana Code 6-3-1-3.5 – Adjusted Gross Income From there, you reduce taxable income through items reported on Schedule 1.
Deductions
The two most commonly claimed deductions cover housing. The renter’s deduction allows up to $3,000 of rent paid on your principal residence, or $1,500 if married filing separately.9Indiana Department of Revenue. Income Tax Information Bulletin 38 – Renters Deduction The homeowner’s property tax deduction allows up to $2,500 of property taxes paid on your Indiana home. You claim one or the other, not both, and you’ll need your lease or property tax statement as backup.
Credits
Contributions to a CollegeChoice 529 education savings plan generate a credit equal to 20% of what you contribute, up to a maximum credit of $1,500 per year, or $750 if married filing separately.10Indiana529 Direct Savings Plan. Tax Advantages Because it’s a credit rather than a deduction, it reduces tax dollar for dollar: a $1,000 contribution cuts $200 off the bill. Keep your account statements as proof.
Personal Exemptions
Each person on the return knocks $1,000 off taxable income: $1,000 for you, $1,000 for your spouse on a joint return, and $1,000 per dependent.11Indiana Department of Revenue. Income Tax Information Bulletin 117 Additional $1,000 exemptions apply for being age 65 or older or blind.12National Finance Center. Indiana State Income Tax Withholding A couple over 65 with two dependents would claim six exemptions, or $6,000, before any deductions.
Credit for Taxes Paid to Another State
If you’re an Indiana resident who earned income in another state and paid income tax there, Indiana offers a credit to prevent double taxation. Attach a copy of the other state’s return along with a worksheet showing how you calculated the credit.13Indiana Department of Revenue. Application of State and County Income Taxes to Residents with Out-of-State Income and Nonresidents with Indiana Source Income The credit covers individual income tax only, not property tax, business tax, or other levies.
Different rules apply if you work in Kentucky, Michigan, Ohio, Pennsylvania, or Wisconsin. Indiana has reciprocal agreements with those five states covering wages, salaries, tips, and commissions.13Indiana Department of Revenue. Application of State and County Income Taxes to Residents with Out-of-State Income and Nonresidents with Indiana Source Income You report that income to Indiana as if you earned it here and cannot claim a credit for tax withheld by the other state. Instead, you file a refund claim with the other state to recover what was withheld. The reciprocal agreements cover wage income only; investment income, rental income, and business profits earned in those states still use the standard credit approach.
How to Submit Your Return
Electronic filing through INTIME is the fastest route. You get immediate confirmation, and refunds from e-filed returns typically arrive within three weeks.14Indiana Department of Revenue. Check the Status of Your Refund If you owe, paying by bank transfer (ACH) through INTIME is free. Credit and debit card payments carry a convenience fee.15Indiana Department of Revenue. Payments and Billing
If you file on paper, the mailing address depends on whether payment is enclosed. Returns with payment go to Indiana Department of Revenue, PO Box 7224, Indianapolis, IN 46207-7224. Returns without payment go to PO Box 40, Indianapolis, IN 46206-0040. Put the return on top, supporting schedules in the middle, and W-2s at the back. Paper returns can take up to 12 weeks to process, so plan accordingly if you’re expecting a refund.14Indiana Department of Revenue. Check the Status of Your Refund
Keep copies of the filed return and all supporting documents for at least three years from the filing date.
Fixing a Return After You File
If you find an error after filing, you correct it by filing an amended return. For tax years 2021 and later, there’s no separate amendment form. You refile Form IT-40 and check the “Amended” box at the top.16Indiana Department of Revenue. Amend A Return Attach any schedules that changed, and include all schedules, even unchanged ones.
You have three years from the original due date (or the date tax was paid, whichever is later) to file an amendment. If the correction creates additional tax owed, pay it as soon as you can, because interest and penalties run from the original due date. Don’t file an amendment just to fix a math error — the Department of Revenue corrects those automatically — and don’t file one solely to submit a forgotten W-2 unless it changes your reported income.16Indiana Department of Revenue. Amend A Return