Indiana Business Tax Extension

Indiana Business Tax Extension LLC / Partnership – S Corporation – C Corporation – Fiduciary / Estate / Trust

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Indiana Quick Reference
LLC / Partnership • Business Tax Extension
State Indiana (IN)
Entity Type LLC / Partnership
Extension ✓ Auto with Federal
Federal Form IRS Form 7004
State Form Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns (payment only)
Original Deadline March 16, 2026
Extended Deadline September 15, 2026

Indiana Business Tax Extension – LLC / Partnership

Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns  •  LLC / Partnership
Original deadline: March 16, 2026 Extended to: September 15, 2026 Extension: 6 months automatic

Indiana LLC & Partnership Tax Extension

Indiana LLCs and partnerships file composite and withholding returns with the Indiana Department of Revenue. Indiana automatically extends your filing deadline when you hold an approved federal IRS Form 7004–no separate state extension application is needed to receive the September 15, 2026 extended due date.

Original Deadline March 16, 2026
Extended Deadline September 15, 2026
Payment Due March 16 – Indiana’s extension covers the filing deadline only. Any Indiana LLC or partnership tax owed must be remitted by March 16, 2026. When the extended return is filed, the federal extension form must be attached and the extension box on the front page of the return must be checked.

How the Extension Works

Obtain approval for IRS Form 7004 before March 16, 2026 and Indiana automatically extends your LLC or partnership return to September 15, 2026. Pay any Indiana tax owed using Form E-6 or electronically through INtax (Indiana’s online tax portal) by March 16. Mail payments to: Indiana Department of Revenue, Corporate Tax Division, P.O. Box 7228, Indianapolis, IN 46207-7228. When filing the return, attach the federal extension and check the extension box on the front page.

Indiana assesses a flat 10% failure-to-file penalty on any tax due. Filing by September 15, 2026 even if only a small amount is owed avoids this penalty entirely.

Best Practices

  • File IRS Form 7004 before March 16, 2026 to activate Indiana’s automatic 6-month extension–no state form required.
  • Remit any Indiana LLC or partnership tax with Form E-6 or via INtax by March 16, 2026.
  • When filing the extended return, attach the approved federal extension and check the extension box on the front page.
  • File your completed Indiana LLC or partnership return by September 15, 2026.

Working with a Tax Professional

LLC / Partnership returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your Indiana return is filed accurately and on time.

  1. Get matched with a verified U.S.-based CPA or Enrolled Agent
  2. Upload your business documents via secure drag-and-drop
  3. Review your return with transparent, upfront pricing
  4. Your TaxPro files the Indiana return by September 15, 2026

Connect with a TaxPro →

How to Pay

Indiana requires online payment for tax amounts of $750 or more. Submit electronically via the Indiana Online Tax Extension Payment portal. For amounts under $750, complete Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns and mail with your payment.

Online – Required $750+

Indiana Online Payment Portal

Submit electronically through the Indiana Online Tax Extension Payment system. Required for all payments $750 and above.

Mail – Under $750

Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns by Check

Download Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns and mail with your check or money order. Include your EIN and tax year on the check.

Indiana Department of Revenue
Corporate Tax Division
P.O. Box 7228, Indianapolis, IN 46207-7228

Late Filing & Payment Penalties

Penalty TypeAmount
Failure to File10% penalty of amount of tax due
Failure to Pay10% penalty of amount held in trust

LLC / Partnership Quick Reference

State AbbreviationIN
Entity TypeLLC / Partnership
Extension StatusAutomatic with approved IRS Form 7004
Original Filing DeadlineMarch 16, 2026
Extended Filing DeadlineSeptember 15, 2026
Payment DueMarch 16, 2026 (100% of tax owed)
Payment FormForm E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns
Online PaymentIndiana Online Tax Extension Payment
State AgencyIndiana Department of Revenue
Failure to File Penalty10% penalty of amount of tax due
Failure to Pay Penalty10% penalty of amount held in trust

Indiana Business Tax Extension – S Corporation

Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns  •  S Corporation
Original deadline: March 16, 2026 Extended to: September 15, 2026 Extension: 6 months automatic

Indiana S Corporation Tax Extension

Indiana S corporations that elect to pay composite tax on behalf of nonresident shareholders file with the Indiana Department of Revenue. Holding an approved federal IRS Form 7004 extends your Indiana S corporation return to September 15, 2026 automatically–Indiana requires no additional state extension form.

Original Deadline March 16, 2026
Extended Deadline September 15, 2026
Indiana Tax Due March 16 – The filing extension does not extend your payment obligation. Any Indiana S corporation tax owed must be paid by March 16, 2026. When filing the extended return, attach the federal extension and mark the extension checkbox on the front page of the Indiana return.

How the Extension Works

An approved IRS Form 7004 automatically extends your Indiana S corporation deadline to September 15, 2026. Submit any Indiana tax owed by March 16, 2026 using Form E-6 or through Indiana’s INtax portal. Mail payments to Indiana Department of Revenue, Corporate Tax Division, P.O. Box 7228, Indianapolis, IN 46207-7228. Attach the federal extension approval to the Indiana return and check the extension box on the front page when you file.

Indiana’s composite income tax for nonresident S corporation shareholders is calculated at the individual graduated rate. Ensure your composite payment estimate accounts for all nonresident shareholders included on the composite election.

Best Practices

  • Secure an approved IRS Form 7004 by March 16, 2026–Indiana’s S corporation extension to September 15, 2026 follows automatically.
  • Pay Indiana S corporation taxes via Form E-6 or through INtax by March 16, 2026.
  • Attach the federal extension approval to the Indiana return and check the extension checkbox on the front page.
  • File the completed Indiana S corporation return by September 15, 2026.

Working with a Tax Professional

S Corporation returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your Indiana return is filed accurately and on time.

  1. Get matched with a verified U.S.-based CPA or Enrolled Agent
  2. Upload your business documents via secure drag-and-drop
  3. Review your return with transparent, upfront pricing
  4. Your TaxPro files the Indiana return by September 15, 2026

Connect with a TaxPro →

How to Pay

Indiana requires online payment for tax amounts of $750 or more. Submit electronically via the Indiana Online Tax Extension Payment portal. For amounts under $750, complete Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns and mail with your payment.

Online – Required $750+

Indiana Online Payment Portal

Submit electronically through the Indiana Online Tax Extension Payment system. Required for all payments $750 and above.

Mail – Under $750

Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns by Check

Download Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns and mail with your check or money order. Include your EIN and tax year on the check.

Indiana Department of Revenue
Corporate Tax Division
P.O. Box 7228, Indianapolis, IN 46207-7228

Late Filing & Payment Penalties

Penalty TypeAmount
Failure to File10% penalty of amount of tax due
Failure to Pay10% penalty of amount held in trust

S Corporation Quick Reference

State AbbreviationIN
Entity TypeS Corporation
Extension StatusAutomatic with approved IRS Form 7004
Original Filing DeadlineMarch 16, 2026
Extended Filing DeadlineSeptember 15, 2026
Payment DueMarch 16, 2026 (100% of tax owed)
Payment FormForm E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns
Online PaymentIndiana Online Tax Extension Payment
State AgencyIndiana Department of Revenue
Failure to File Penalty10% penalty of amount of tax due
Failure to Pay Penalty10% penalty of amount held in trust

Indiana Business Tax Extension – C Corporation

Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns  •  C Corporation
Original deadline: May 15, 2026 Extended to: November 15, 2026 Extension: 6 months automatic

Indiana C Corporation Tax Extension

Indiana C corporations pay the state’s corporate income tax to the Indiana Department of Revenue. Indiana grants C corporations a 7-month filing extension when an approved federal IRS Form 7004 is in place–extending the deadline from May 15 all the way to November 15, 2026 without any separate state form required.

Original Deadline May 15, 2026
Extended Deadline November 15, 2026
Corporate Tax Due May 15 – Indiana’s 7-month C corporation extension covers the filing deadline only. Any Indiana corporate income tax owed must be remitted by May 15, 2026 to avoid the 10% failure-to-pay penalty. Attach the federal extension to the Indiana return when eventually filing.

How the Extension Works

File IRS Form 7004 before May 15, 2026 to activate Indiana’s automatic 7-month C corporation extension–no state extension form is required. Pay any Indiana corporate tax owed by May 15 using Form E-6 or electronically through INtax. Mail payments to: Indiana Department of Revenue, Corporate Tax Division, P.O. Box 7228, Indianapolis, IN 46207-7228. When you file by November 15, attach the federal extension approval and mark the extension box on the front page of the Indiana return.

Indiana’s C corporation extension runs 7 months–one month longer than the 6-month extension available to pass-through entities. This extra time is particularly useful for corporations completing complex multi-state apportionment schedules.

Best Practices

  • File IRS Form 7004 before May 15, 2026 to lock in Indiana’s 7-month C corporation extension to November 15, 2026.
  • Pay Indiana corporate tax with Form E-6 or through INtax by May 15, 2026.
  • Attach the federal extension and check the extension box on the Indiana return front page when filing by November 15.
  • File the completed Indiana C corporation return by November 15, 2026 to avoid the 10% failure-to-file penalty.

Working with a Tax Professional

C Corporation returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your Indiana return is filed accurately and on time.

  1. Get matched with a verified U.S.-based CPA or Enrolled Agent
  2. Upload your business documents via secure drag-and-drop
  3. Review your return with transparent, upfront pricing
  4. Your TaxPro files the Indiana return by November 15, 2026

Connect with a TaxPro →

How to Pay

Indiana requires online payment for tax amounts of $750 or more. Submit electronically via the Indiana Online Tax Extension Payment portal. For amounts under $750, complete Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns and mail with your payment.

Online – Required $750+

Indiana Online Payment Portal

Submit electronically through the Indiana Online Tax Extension Payment system. Required for all payments $750 and above.

Mail – Under $750

Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns by Check

Download Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns and mail with your check or money order. Include your EIN and tax year on the check.

Indiana Department of Revenue
Corporate Tax Division
P.O. Box 7228, Indianapolis, IN 46207-7228

Late Filing & Payment Penalties

Penalty TypeAmount
Failure to File10% penalty of amount of tax due
Failure to Pay10% penalty of amount held in trust

C Corporation Quick Reference

State AbbreviationIN
Entity TypeC Corporation
Extension StatusAutomatic with approved IRS Form 7004
Original Filing DeadlineMay 15, 2026
Extended Filing DeadlineNovember 15, 2026
Payment DueMay 15, 2026 (100% of tax owed)
Payment FormForm E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns
Online PaymentIndiana Online Tax Extension Payment
State AgencyIndiana Department of Revenue
Failure to File Penalty10% penalty of amount of tax due
Failure to Pay Penalty10% penalty of amount held in trust

Indiana Business Tax Extension – Fiduciary / Estate / Trust

Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns  •  Fiduciary / Estate / Trust
Original deadline: April 15, 2026 Extended to: October 15, 2026 Extension: 6 months automatic

Indiana Fiduciary Tax Extension

Indiana estates and trusts with fiduciary income tax obligations file with the Indiana Department of Revenue. An approved federal Form 8868 extension automatically extends the Indiana fiduciary return from April 15 to October 15, 2026–no separate Indiana form is required.

Original Deadline April 15, 2026
Extended Deadline October 15, 2026
Fiduciary Tax Due April 15 – The extension delays the filing deadline, not the payment due date. Any Indiana fiduciary income tax must be paid by April 15, 2026. When the extended return is filed, attach the federal extension approval and check the extension box on the front page of the Indiana return.

How the Extension Works

File IRS Form 8868 with the IRS before April 15, 2026 to extend the Indiana fiduciary return to October 15, 2026 automatically. Remit any Indiana fiduciary tax using Form IT-41ES | Fiduciary Payment Voucher or through INtax by April 15. Mail payments to: Indiana Department of Revenue, Corporate Tax Division, P.O. Box 7228, Indianapolis, IN 46207-7228. When filing, attach the federal extension and confirm the extension box is checked on the front page.

Indiana fiduciary income taxes apply to Indiana-source income of estates and trusts. If the trust has Indiana beneficiaries, the trustee should also confirm any composite election or withholding obligations are current before the April 15 deadline.

Best Practices

  • File IRS Form 8868 before April 15, 2026 to trigger Indiana’s automatic 6-month fiduciary extension to October 15, 2026.
  • Pay Indiana fiduciary tax via Form IT-41ES or through INtax by April 15, 2026.
  • Attach the federal extension and check the extension box on the front page of the Indiana fiduciary return when filing.
  • File the completed Indiana fiduciary return by October 15, 2026 to avoid the 10% failure-to-file penalty.

Working with a Tax Professional

Fiduciary / Estate / Trust returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your Indiana return is filed accurately and on time.

  1. Get matched with a verified U.S.-based CPA or Enrolled Agent
  2. Upload your business documents via secure drag-and-drop
  3. Review your return with transparent, upfront pricing
  4. Your TaxPro files the Indiana return by October 15, 2026

Connect with a TaxPro →

How to Pay

Indiana requires online payment for tax amounts of $750 or more. Submit electronically via the Indiana Online Tax Extension Payment portal. For amounts under $750, complete Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns and mail with your payment.

Online – Required $750+

Indiana Online Payment Portal

Submit electronically through the Indiana Online Tax Extension Payment system. Required for all payments $750 and above.

Mail – Under $750

Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns by Check

Download Form E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns and mail with your check or money order. Include your EIN and tax year on the check.

Indiana Department of Revenue
Corporate Tax Division
P.O. Box 7228, Indianapolis, IN 46207-7228

Late Filing & Payment Penalties

Penalty TypeAmount
Failure to File10% penalty of amount of tax due
Failure to Pay10% penalty of amount held in trust

Fiduciary / Estate / Trust Quick Reference

State AbbreviationIN
Entity TypeFiduciary / Estate / Trust
Extension StatusAutomatic with approved IRS Form 7004
Original Filing DeadlineApril 15, 2026
Extended Filing DeadlineOctober 15, 2026
Payment DueApril 15, 2026 (100% of tax owed)
Payment FormForm E-6 | Request for Indiana Corporate Estimated Quarterly Income Tax Returns
Online PaymentIndiana Online Tax Extension Payment
State AgencyIndiana Department of Revenue
Failure to File Penalty10% penalty of amount of tax due
Failure to Pay Penalty10% penalty of amount held in trust

Extended? Your Indiana Business Return Deadline Is Coming Up.

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