Indiana Form IT-40 is the official tax return form used by full-year residents of Indiana to file their individual income taxes. This form is required to report your income, calculate your tax liability, claim deductions and credits, and determine the amount of tax owed or the refund you’re entitled to receive. The IT-40 is designed specifically for those who lived in Indiana the entire year and includes fields to report both federal and state adjustments, local county taxes, and additional tax credits.
The form must be filed by April 15, 2027, to avoid penalties or interest for late filing. It also requires you to provide specific information about your income, deductions, and taxes paid throughout the year. Additionally, certain schedules (attachments) may be required to report specific items like add-backs, deductions, exemptions, and credits. This guide will walk you through the process of completing the IT-40 form line by line, making it easy to file your taxes correctly and on time.
How To File Indiana Form IT-40
Filing Indiana Form IT-40 involves a few key steps. You can file the form either electronically through Indiana’s online filing system or by mailing a completed paper form to the Indiana Department of Revenue. Follow these steps to ensure your form is filed properly:
- Gather Required Documents: Collect your federal tax return (Form 1040 or 1040-SR), W-2s, 1099s, and any other income-related documents.
- Download The IT-40 Form: Obtain the latest version of the IT-40 from the Indiana Department of Revenue website or use a fillable PDF.
- Complete All Sections: Fill out each line of the form accurately. Refer to your federal tax return and supporting schedules as needed.
- Attach Required Schedules: Include all applicable schedules, such as Schedule 1 (Indiana Add-Backs), Schedule 2 (Indiana Deductions), and more.
- Double-Check Your Work: Ensure all calculations are correct, and verify that all fields are complete.
- Sign The Form: You and your spouse (if filing jointly) must sign and date the document.
- Submit The Form: File electronically or mail your completed form to the appropriate address provided on the form instructions.
How To Complete Indiana Form IT-40: Line-By-Line Instructions
Personal Information Section
- Name And Address: Enter your full name, address, city, state, and ZIP code. If filing jointly, include your spouse’s name as well.
- Social Security Number (SSN): Provide your SSN and your spouse’s SSN if applicable.
- Filing Status: Mark the appropriate box if you’re married filing separately or applying for an Individual Taxpayer Identification Number (ITIN).
- Residency Details: Enter the 2-digit county codes found on Schedule CT-40 for the county where you and your spouse lived and worked as of January 1, 2026.
Line 1: Federal Adjusted Gross Income (AGI)
Enter your federal adjusted gross income from your federal tax return (Form 1040 or 1040-SR, line 11). This serves as the starting point for calculating your state taxes.
Line 2: Indiana Add-Backs
Transfer the total from Schedule 1, line 7, to this line. Enclose Schedule 1 with your return. Add-backs include any adjustments required by Indiana that differ from federal income calculations.
Line 3: Total Income
Add the amounts on lines 1 and 2. This is your total income before deductions.
Line 4: Indiana Deductions
Enter the amount from Schedule 2, line 12. Indiana offers specific deductions that reduce your taxable income, such as deductions for military service or qualified education expenses. Enclose Schedule 2.
Line 5: Indiana Taxable Income
Subtract line 4 (Indiana Deductions) from line 3 (Total Income). This is your taxable income for the state of Indiana.
Line 6: Indiana Exemptions
Enter the amount from Schedule 3, line 7. This includes personal and dependent exemptions. Enclose Schedule 3 with your form.
Line 7: Indiana Adjusted Gross Income
Subtract line 6 (Exemptions) from line 5 (Taxable Income). This is your Indiana adjusted gross income.
Line 8: State Adjusted Gross Income Tax
Multiply the amount on line 7 by 3% (0.03). This is your calculated state income tax. If the result is less than zero, leave this line blank.
Line 9: County Tax
Enter your county tax due from Schedule CT-40. Use the county codes provided and calculate the tax based on where you lived and worked as of January 1, 2026.
Line 10: Other Taxes
Include any other taxes due, as reported on Schedule 4, line 4. Enclose Schedule 4 with your return.
Line 11: Total Taxes
Add lines 8, 9, and 10. This is your total Indiana tax liability.
Line 12: Credits From Schedule 5
Enter the total credits from Schedule 5, line 13. These may include credits for taxes paid to other states or earned income credits. Enclose Schedule 5.
Line 13: Offset Credits
Include offset credits from Schedule 6, line 8. These credits can reduce your tax liability. Enclose Schedule 6.
Line 14: Total Credits
Add lines 12 and 13. This is the total amount of credits you are claiming.
Line 15: Total Taxes Due
Transfer the amount from line 11 (Total Taxes).
Line 16: Overpayment
If line 14 (Total Credits) is greater than line 15 (Total Taxes), subtract line 15 from line 14.
Line 17: Donations
Enter the amount you wish to donate from your overpayment. Donations can’t exceed the overpayment amount.
Line 18: Refund
Subtract line 17 from line 16. This is your refund amount.
Line 19a-19d: Estimated Tax Application
Specify how much of your overpayment you want to apply to next year’s estimated tax, broken down into state and county taxes.
Line 20: Penalty For Underpayment
Enter any penalties for underpayment of estimated taxes, as calculated on Schedule IT-2210 or IT-2210A.
Line 21: Final Refund Amount
Subtract lines 19d and 20 from line 18. This is your final refund amount.
Line 23: Amount Owed
If line 15 (Taxes) is greater than line 14 (Credits), subtract line 14 from line 15, and add any penalties from line 20.
Lines 24-26: Late Filing Penalties And Total Amount Due
Include penalties and interest for late filing (lines 24 and 25), and add these to line 23 to determine your total amount due (line 26).