Indiana

Corporate income tax

Form IT-20 is due the later of the 15th day of the 4th month after year end or one month after the federal return is due (IC 6-3-4-3); because the federal C-corp return is due the 15th day of the 4th month, the Indiana IT-20 is generally due the 15th day of the 5th month following the end of the taxable year.

Extension. Extended due date for calendar-year IT-20 is November 15 per DOR's deadlines page (30 days after the federal extended date)

Partnerships and S corporations

Pass-through entity tax (PTET) enacted by SEA 2 (signed February 22, 2023), retroactive to taxable years beginning on or after January 1, 2022: qualifying pass-through entities may elect annually via Form IN-PTET to pay tax at the entity level; owners receive a refundable credit.

Sales and use tax

Due date. Monthly ST-103 returns are due the 20th of the following month for early filers (average monthly liability of $1,000 or more) and the last day (30th) of the following month for other monthly filers; annual returns are due January 31 for the prior calendar year.

Filing frequency. Filing frequency is based on the average monthly liability throughout the tax year; DOR assigns monthly (early or standard) or annual filing. Average monthly tax over $5,000 requires EFT payment.

Thresholds. Early filer (20th): average monthly liability $1,000 or more; standard monthly (30th): under $1,000; annual-filer dollar threshold not published on fetched DOR pages.

Prepayments. None stated other than the accelerated 20th due date for early filers.

Notes

Indiana deliberately keeps the state return one month behind the federal date, so calendar-year C corps file May 15 while S corps and partnerships file April 15. Indiana has no franchise or gross receipts tax on general businesses.