Indiana sales tax due dates for 2026
Every date below comes from the state's published deadline rule (dataset 2026.07.0) and is already moved to the next business day when it lands on a weekend or federal holiday. Your account's assigned filing frequency decides which table applies.
Monthly Indiana sales tax due dates
Rule: 20th of the following month (early filers). This cadence is flagged for manual review against the state source before relying on it.
| Period | Period ends | Return due |
|---|---|---|
| January 2026 | Jan 31, 2026 | Feb 20, 2026 |
| February 2026 | Feb 28, 2026 | Mar 20, 2026 |
| March 2026 | Mar 31, 2026 | Apr 20, 2026 |
| April 2026 | Apr 30, 2026 | May 20, 2026 |
| May 2026 | May 31, 2026 | Jun 22, 2026 (moved: 2026-06-20 falls on a Saturday) |
| June 2026 | Jun 30, 2026 | Jul 20, 2026 |
| July 2026 | Jul 31, 2026 | Aug 20, 2026 |
| August 2026 | Aug 31, 2026 | Sep 21, 2026 (moved: 2026-09-20 falls on a Sunday) |
| September 2026 | Sep 30, 2026 | Oct 20, 2026 |
| October 2026 | Oct 31, 2026 | Nov 20, 2026 |
| November 2026 | Nov 30, 2026 | Dec 21, 2026 (moved: 2026-12-20 falls on a Sunday) |
| December 2026 | Dec 31, 2026 | Jan 20, 2027 |
- Indiana has two monthly classes: early filers (avg ≥ $1,000/month) file by the 20th; others by the 30th (February: the 28th). The earlier date is shown — verify the assigned class.
Annual Indiana sales tax due dates
Rule: January 31 following the calendar year.
| Period | Period ends | Return due |
|---|---|---|
| Calendar year 2026 | Dec 31, 2026 | Feb 1, 2027 (moved: 2027-01-31 falls on a Sunday) |
Indiana filing notes
No additional state-specific filing notes are recorded for this cadence set.
Return and form
The principal repository-tracked return is ST-103. Paper eligibility is taxpayer-specific; electronic filing or a waiver may control.
Paper filing posture: taxpayer specific
Official Indiana filing resources
File Indiana sales tax from reviewed data, not spreadsheets
Prophit.ai tracks every Indiana due date above inside the return workspace, builds the period from your transaction data, and produces worksheet for portal entry that a reviewer approves before anything is submitted.
Need every state at once? Download the 2026 sales tax filing calendar (CSV + ICS, all states, weekend/holiday-adjusted).
Workflow support does not by itself establish registration, filing authority, credentials, agency acceptance, or tax advice. Confirm your assigned filing frequency with the state.
Indiana sales tax filing questions
01When is Indiana sales tax due?
Monthly Indiana sales tax returns are due the 20th of the following month (early filers). When a due date lands on a weekend or federal holiday it moves to the next business day; the 2026 calendar on this page already applies that adjustment.
02How often do you file sales tax in Indiana?
Indiana assigns a filing frequency to each account. The published cadences are monthly and annual filing; the state assigns the frequency based on tax volume and notifies the account, so confirm the assigned basis before relying on a calendar.
03What form is used to file Indiana sales tax?
The Indiana return tracked here is ST-103. The principal repository-tracked return is ST-103. Paper eligibility is taxpayer-specific; electronic filing or a waiver may control.
04What happens if a Indiana due date falls on a weekend or holiday?
The due date moves to the next business day. In 2026, 4 of the Indiana due dates listed on this page are adjusted for a weekend or federal holiday; each adjusted date is marked in the calendar.
05Can Indiana sales tax be filed on paper?
Paper filing posture tracked for Indiana: taxpayer specific. The principal repository-tracked return is ST-103. Paper eligibility is taxpayer-specific; electronic filing or a waiver may control.
Reviewed and current as of August 22, 2026. Read the full Indiana sales tax guide for rates, sourcing, products, exemptions, and marketplace rules.