Indiana State Tax Forms (2026 & 2027 Guide)

Indiana uses a straightforward set of state tax forms due to its flat income tax system.

Most taxpayers will file using a primary form, with additional schedules depending on income, deductions, and credits.

Understanding which forms apply to your situation can help you file accurately and avoid delays.

Main Indiana Tax Forms

Indiana has different primary forms depending on residency.

• IT-40 → Resident Income Tax Return
• IT-40PNR → Part-Year Resident and Nonresident Income Tax Return

These forms are used to report income, calculate tax, and claim deductions or credits.

Common Indiana Supporting Forms

Depending on your financial situation, you may need additional schedules.

• Schedule 1 → Add-backs and deductions
• Schedule 2 → Credits
• Schedule 3 → Additional credits and taxes
• Schedule CT-40 → County tax computation

These schedules help ensure accurate reporting and proper tax calculation.

County Tax Forms (Important)

Indiana also has county-level income taxes.

• County tax is calculated within Schedule CT-40
• Rates vary depending on your county of residence and employment

This is an important part of your total Indiana tax liability.

Forms for Special Situations

Indiana provides additional forms for specific tax needs.

• IT-40ES → Estimated tax payments
• IT-9 → Extension of time to file
• IT-40X → Amended return

These forms are used if you owe taxes, need more time, or need to correct a return.

How Indiana Taxes Income

Indiana uses a flat state income tax rate.

• All taxable income → approximately 3.15%

In addition, county taxes apply separately.

Example: If your taxable income is $60,000, your state tax would be about $1,890, plus any applicable county tax based on your location.

Deductions and Special Rules

Indiana has its own tax rules that differ from federal law.

• No traditional federal-style standard deduction
• Personal exemptions and credits available
• State-specific deductions and adjustments

These can affect your taxable income.

Who Needs to File

You generally need to file an Indiana return if you:

• Are a resident with taxable income
• Earn income from Indiana as a nonresident
• Have state tax withheld and want a refund

Part-year residents must report income earned while living in the state.

Electronic Filing Recommendation 💻

• Use tax software to automatically generate IT-40 or IT-40PNR
• Ensure the correct county tax is applied
• Review all credits and deductions carefully
• E-file for faster refunds and fewer errors

Summary

Indiana state taxes are filed using Form IT-40 for residents or IT-40PNR for nonresidents and part-year residents, along with supporting schedules and county tax calculations.

Because Indiana uses a flat tax system combined with county taxes, understanding the correct forms and local rates is essential for accurate filing and avoiding underpayment.