2025 Indiana State Tax Deadlines

Indiana Individual Income Tax Filing deadlines and extensions for 2025 tax professionals to reference when working with clients in Indiana.

If you are a resident or have been involved in significant business operations within Indiana then you might be required to file Indiana State Taxes. We look at the most important tax deadlines and tax extensions for Indiana in 2025.

2025 Indiana State Tax Deadlines

If your clients are residents or have been involved in significant business operations within Indiana, they might be required to file Indiana State Taxes. This document outlines the most important tax deadlines and tax extensions for Indiana in 2025.

Indiana Business Tax Deadlines for 2025

C Corporation

Indiana C Corporation Tax Deadlines for 2025 

You must file and pay Corporate Income Taxes in Indiana by April 15, 2026.

• File Online with the Indiana Department of Revenue’s INTIME service.
• File by Mail must be postmarked by the due date.
• Form IT-20 – Indiana Corporate Adjusted Gross Income Tax Return.

Extension to File Taxes in Indiana for 2025
The Extension Deadline for Indiana corporate tax returns is October 15, 2026.

Indiana automatically grants a six-month extension on filing corporate income tax returns. This means you do not need to file for an extension in Indiana.

This is an extension to FILE, not an extension to PAY – payment is still due April 15, 2026.

Pass-Throughs

Indiana S Corporation & Partnership Tax Deadlines for 2025
You must file in Indiana by April 15, 2026.

• File Online with Indiana Department of Revenue’s INTIME service
• File by Mail must be postmarked by the due date
• Forms:
  • IT-65 – Indiana Partnership Return
  • IT-20S – Indiana S Corporation Income Tax Return

Extension to File S Corporation & Partnership Taxes in Indiana for 2025
The Extension Deadline for Indiana pass-through entity tax returns is October 15, 2026.

Indiana automatically grants a six-month extension on filing pass-through entity tax returns. This means you do not need to file for an extension in Indiana.

This is an extension to FILE, not an extension to PAY – payment is still due April 15, 2026.

Indiana Individual Tax Deadlines for 2025

Estimated Tax Deadline for Indiana 2025
Estimated tax payments are due:

• April 15, 2025
• June 16, 2025
• September 15, 2025
• January 15, 2026

See Form ES-40 instructions for the amount to pay with each voucher.

Individual Tax Deadline for Indiana 2025
You must file and pay Individual Income Taxes in Indiana by April 15, 2026.

• File Online with the Indiana Department of Revenue’s INTIME service
• File by Mail must be postmarked by the due date
• Forms:
  • IT-40 – Residents
  • IT-40PNR – Part-Year Residents and Full-Year Nonresidents

Extension to File Taxes in Indiana for 2025
The Extension Deadline for Indiana individual income tax returns is November 15, 2026.

Indiana automatically grants a six-month extension on filing personal income taxes. This means you do not need to file for an extension in Indiana.

This is an extension to FILE, not an extension to PAY – payment is still due April 15, 2026.

Sources

• Indiana Department of Revenue – Filing Information
• Indiana Department of Revenue – Tax Forms
• Indiana Department of Revenue – Extension Information

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The material discussed on this page is meant for general illustration and/or informational purposes only and is not to be construed as investment, tax, or legal advice. You must exercise your own independent professional judgment, recognizing that advice should not be based on unreasonable factual or legal assumptions or unreasonably rely upon representations of the client or others. Further, any advice you provide in connection with tax return preparation must comply in full with the requirements of IRS Circular 230.