Indiana Business Tax Deadlines (2026)
Next: June 15, 2026 — Federal & Indiana Q2 Estimated Tax Payment
Next Deadline: June 15, 2026 — Federal & Indiana Q2 Estimated Tax Payment
Federal Tax Deadlines (2026)
| Form | Who Files | Due Date | Extension Deadline |
|---|---|---|---|
| Form 1040 (Schedule C) | Sole proprietors | April 15 | October 15 |
| Form 1065 | Partnerships, Multi-member LLCs | March 15 | September 15 |
| Form 1120-S | S-Corporations | March 15 | September 15 |
| Form 1120 | C-Corporations | April 15 | October 15 |
| Form 990 | Nonprofits | May 15 | November 15 |
| Estimated Taxes (Q1) | All | April 15 | — |
| Estimated Taxes (Q2) | All | June 15 | — |
| Estimated Taxes (Q3) | All | September 15 | — |
| Estimated Taxes (Q4) | All | January 15, 2027 | — |
Indiana State Tax Deadlines (2026)
| Tax Type | Due Date | Form/Filing | Notes |
|---|---|---|---|
| Individual Income Tax | April 15 | Form IT-40 | Flat 3.05% rate + county tax |
| Corporate Income Tax | April 15 | Form IT-20 | Flat 4.9% rate |
| S-Corp Return | April 15 | Form IT-20S | Pass-through entity |
| Partnership Return | April 15 | Form IT-65 | Pass-through; due April 15 (not March 15) |
| Sales Tax (Monthly) | 20th of following month | Via INTIME | State rate 7% |
| Withholding Tax (Monthly) | Last day of following month | WH-1 via INTIME | Employers |
| Business Entity Report | Biennially | Filed with Secretary of State | Due in anniversary month; no fee |
| County Income Tax | With state return | Included in IT-40 | Rates vary 0.5%–3.38% by county |
| Estimated Income Tax (Q1) | April 15 | Form ES-40 / IT-20ES | — |
| Estimated Income Tax (Q2) | June 15 | Form ES-40 / IT-20ES | — |
| Estimated Income Tax (Q3) | September 15 | Form ES-40 / IT-20ES | — |
| Estimated Income Tax (Q4) | January 15, 2027 | Form ES-40 / IT-20ES | — |
Quarterly Estimated Tax Deadlines in Indiana
Indiana follows the federal estimated tax payment schedule:
Estimated payments are required if you expect to owe $1,000 or more in combined state and county income tax.
Indiana-Specific Tax Requirements
Indiana has a flat individual income tax rate of 3.05%, one of the lowest flat rates in the nation. However, Indiana also levies county income taxes that range from 0.5% to 3.38% depending on the county of residence, which can significantly increase the effective rate. The corporate income tax rate is 4.9%. Indiana's partnership and S-corp returns are due April 15 (not March 15 like most states), aligning with the individual return deadline.
Indiana's sales tax rate is 7%, uniform statewide with no local additions. This is one of the highest state sales tax rates but simplifies compliance since there's only one rate. The economic nexus threshold for remote sellers is $100,000 in sales or 200 transactions. Indiana does not have a franchise tax, gross receipts tax, or inventory tax.
Business entities must file a biennial Business Entity Report with the Indiana Secretary of State during the anniversary month of formation. There is no filing fee for the report, but failure to file can lead to administrative dissolution. Indiana uses the INTIME portal for all tax filings and payments. The state's overall tax structure is considered business-friendly.
What Happens If You Miss an Indiana Tax Deadline?
Indiana Department of Revenue
Get Your Books Ready Before Tax Season
Indiana's flat tax rates are simple, but the county tax adds a variable that makes accurate income tracking essential. Make sure your QuickBooks reflects the right county allocation before filing.
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