# How to File Indiana Sales Tax Online in 2026

Canonical: https://trykintsugi.com/blog/how-to-file-indiana-sales-tax-online
Published: 2026-09-22

How to file Indiana sales tax online in INTIME: Form ST-103, due dates on the 20th or 30th, zero returns, payment, collection allowance, and penalties.

Indiana sales tax is filed online through **INTIME**, the Indiana Department of Revenue's e-services portal, on the **Sales and Use Tax Voucher (Form ST-103)**. Monthly returns are due on the 20th of the month after the reporting period if your average monthly tax for the preceding year was more than $1,000, and on the 30th day after the period otherwise. Indiana requires businesses to file and pay sales tax electronically, and you must file even when no tax is due.

This guide covers who files and how often, how to get into INTIME, how to file a return, how to report no sales, how to pay, the collection allowance, and what late filing costs.

This article is educational information, not tax advice. Filing rules, thresholds, and penalties can change, so confirm current requirements with the [Indiana Department of Revenue](https://www.in.gov/dor/i-am-a/business-corp/business-faq/) before you file.

## Indiana sales tax filing at a glance

- **Who administers it:** Indiana Department of Revenue.
- **Online portal:** INTIME (Indiana Taxpayer Information Management Engine). Registration for a retail merchant's certificate is done separately, through InBiz.
- **Return:** Form ST-103, Sales and Use Tax Voucher.
- **Filing frequency:** Monthly for most merchants, or annual if your collections are under $1,000 a year.
- **Due dates:** The 20th of the month after the period if your average monthly tax due for the preceding year is more than $1,000, or the 30th day after the period if it is $1,000 or less. A due date on a weekend or holiday moves to the next legal business day.
- **Zero returns:** Required, unless the Indiana tax account has been properly closed.
- **Payment:** Online through INTIME, with electronic funds transfer (EFT) required when your average monthly tax exceeds $5,000.
- **Collection allowance:** Available only when the return and payment are made on or before the due date.
- **Economic nexus:** Gross revenue from sales into Indiana above $100,000 in the current or preceding calendar year.

## Who has to file, and how often

Retail merchants selling taxable goods in Indiana must register with the Department and file sales tax returns. Remote sellers are covered too. The Department says a seller without a physical presence must register and collect once gross revenue from sales into Indiana exceeds $100,000 in the current or preceding calendar year. Since January 1, 2024, Indiana has only that dollar threshold; the older 200-transaction threshold was removed. The threshold counts revenue whether or not the sales are taxable, so a remote seller can owe registration and returns even when it expects none of its sales to be taxed. Our [Indiana sales tax guide](/sales-tax-guides/usa/indiana) covers registration and nexus in more detail. For a product-level example, see our post on [Indiana sales tax exemptions](/blog/indiana-sales-tax-exemption).

The Department's farm markets bulletin sets out how frequency and due dates work. That bulletin is written for farm markets, but it states the general filing schedule for a new merchant. The Department assigns your frequency based on your taxable sales volume for the preceding calendar year:

| Frequency | Who it applies to | Due date |
| --- | --- | --- |
| Monthly | Average monthly tax due for the preceding year over $1,000 | The 20th of the month after the period |
| Monthly | Average monthly tax due for the preceding year of $1,000 or less | The 30th day after the period |
| Annual | Annual collections under $1,000 | 30 days after the period, per the Department's assignment |
| Seasonal | Merchants open only part of the year, if the Department permits | Monthly returns only for the months open |

File on the frequency and due date shown on your own return in INTIME rather than the one you think you qualify for.

## Before you start: your INTIME account

You need a registered retail merchant's certificate before you can file. Businesses register through InBiz, the state's business portal, and the bulletin lists a one-time registration fee of $25. Our [sales tax permit](/blog/sales-tax-permit) overview explains how registration works in general. To file, use INTIME. The Department describes it as a customer portal for individuals, businesses, and tax professionals, and it supports filing returns and paying tax bills.

Before filing, gather your records for the period: total sales, exempt sales or deductions, and any sales where another party, such as a marketplace facilitator, collects the tax. For sales to resellers, see our [Indiana resale certificate](/resale-certificates/indiana) guide for what to collect from buyers.

## Step-by-step: filing Form ST-103 online

1. **Log in to INTIME** and open your sales tax account.
2. **Select the ST-103 for the period due.** Enter only the sales activity for that period.
3. **Enter total sales.** This includes retail, wholesale, manufacturing, and out-of-state sales.
4. **Enter exemptions and deductions.** Include exempt sales and any bad debts expensed during the period.
5. **Enter excluded sales.** These are sales in the total where the obligation to collect tax falls on another party, such as a marketplace facilitator.
6. **Review the tax due.** Taxable sales are total sales minus exemptions and excluded sales, and the return applies the current sales tax rate. Add use tax on any purchases where no sales tax was paid.
7. **Apply the collection allowance if you qualify.** It applies only when the return and payment are on time.
8. **Submit and pay.** Save your confirmation with your records for the period.

The Department asks for one payment per return. Sending several returns with a single payment can credit a payment to the wrong period and produce a tax liability notice that may include penalty and interest.

Filing in Indiana plus other states? Kintsugi files and remits for you, from $75 per filing, with free monitoring. [Book a demo](/kintsugi-demo) or [start free](https://auth.trykintsugi.com/en/signup).

## Rate and calculation pitfalls

Indiana's state sales tax rate is 7%, and the return shows the current rate to use, so calculate from the rate printed on the return rather than from memory. Treat marketplace sales carefully: sales where a marketplace facilitator collects the tax belong on the excluded sales line, not in taxable sales. If you also sell in other states, confirm which returns each one requires. Our [Indiana sales tax calculator](/us-sales-tax-calculator/indiana) shows current rates.

## Due dates and the weekend rule

Monthly returns are due on the 20th of the month after the reporting period if your average monthly tax due for the preceding year was more than $1,000, and on the 30th day after the period if it was $1,000 or less. If the due date printed on your return falls on a weekend or holiday, the due date becomes the next legal business day. The Department's return instructions note that a payment made, or initiated by EFT, after the due date is late. Our [Indiana sales tax due dates](/sales-tax-due-dates#indiana) page lists upcoming dates for every state.

## Filing a zero return

You must file even when you had no sales. The Department's ST-103 instructions say a return must be filed even when no tax is due unless the Indiana tax account has been properly closed. If no return is filed, the Department may file an estimated return using the best information available and issue a tax liability notice. To stop filing, close the account rather than skipping returns. The instructions point to Form BC-100 or closing the business in INTIME.

## Amending a return

The ST-103 instructions do not describe an amended-return process. If you need to correct a return you already filed, start in INTIME and contact the Department through the customer support function in INTIME or at (317) 232-2240 to confirm the current steps.

## Payment methods

The Department states that all businesses in Indiana must file and pay their sales and withholding taxes electronically.

- **INTIME online pay:** Pay through INTIME with your return.
- **EFT:** Required when your average monthly tax exceeds $5,000. If you file before initiating the EFT payment, claim the payment you will initiate on the return's payment line.
- **Check:** The return instructions accept a check payable in U.S. funds to the Indiana Department of Revenue, and say not to send cash. Because businesses must file electronically, confirm with the Department whether you qualify to pay this way.
- **Payment plans:** For payment plans and assistance, the Department lists paymentservices@dor.in.gov.

A faulty payment, such as a bad check, carries a $35 flat fee under the Department's general penalty schedule.

## The collection allowance

Indiana lets you keep a collection allowance from the tax you collect if you file and pay on time. The allowance for a calendar year is based on your tax liability for the 12 months ending June 30 of the prior year. The Department's bulletin on gasoline use tax, which sets out the allowance schedule for sales tax and gasoline use tax together, lists these tiers:

| Tax liability for the prior 12 months ending June 30 | Collection allowance |
| --- | --- |
| $60,000 or less | 0.73% |
| $60,000.01 through $600,000 | 0.53% |
| $600,000.01 or more | 0.26% |

INTIME shows the allowance percentage for your account. A return or payment made after the due date does not qualify, so paying late can cost you the allowance.

## Penalties and interest for late filing

- **Late payment penalty:** 10% of the tax due (sales tax plus use tax) or $5, whichever is greater, for a payment made or initiated by EFT after the due date.
- **Higher penalty:** 20% of the tax due or $5, whichever is greater, if a Notice of Proposed Assessment follows a Notice of Failure to File.
- **Estimated returns:** If the Department prepares an estimated return because none was filed, the penalty is 20% of the tax assessed.
- **Interest:** Charged from the due date to the payment date. The Department sets the rate each year at 7% for 2026 and 6% for 2027.
- **Faulty payments:** A flat $35 fee under the general penalty schedule.

The penalty is not computed on the interest amount. Contact the Department if you believe a penalty was assessed in error.

## Common mistakes to avoid

- **Skipping zero returns.** A return is due every period, even with no sales, until the account is closed.
- **Using the wrong due date.** The 20th applies if your average monthly tax was over $1,000; otherwise the 30th day. Use the date on your own return.
- **Paying late and losing the allowance.** The collection allowance requires the return and payment on or before the due date.
- **Bundling payments.** Submit one payment per return so it is credited to the right period.
- **Mailing a paper return.** Indiana requires businesses to file and pay electronically.
- **Ignoring nexus.** Remote sellers can owe Indiana registration and returns after crossing $100,000 in gross revenue into the state, taxable or not.

## If you receive a sales tax notice

A missed or late return often leads to a letter. Our [Indiana sales tax notices guide](/notice-hub/usa/indiana) explains what notices from the Indiana Department of Revenue mean, why businesses usually receive them, and what to do next. It also points to how to ask for penalty relief where the state publishes a process. Check the date on the notice, match it to your filing period, and follow the instructions on the notice itself.

## More state filing guides

Filing in more than one state? These step-by-step guides cover the portals, due dates, and penalties in other states. See them all in our [state-by-state guide to filing sales tax online](/blog/how-to-file-sales-tax-online-by-state).

- [How to file Ohio sales tax online](/blog/how-to-file-ohio-sales-tax-online)
- [How to file Illinois sales tax online](/blog/how-to-file-illinois-sales-tax-online)
- [How to file Michigan sales tax online](/blog/how-to-file-michigan-sales-tax-online)

## Let Kintsugi file for you

If you sell in Indiana and other states, [Kintsugi's sales tax filing software](/product/sales-tax-filing-software) prepares and files returns on each state's assigned schedule, remits payment, and files zero returns when you had no sales. Monitoring across every US state is free, so you know when you cross a threshold. Filing starts at $75 per filing or registration, with no per-state subscription. See [pricing](/pricing), [start free](https://auth.trykintsugi.com/en/signup), or [book a demo](/kintsugi-demo).

## Frequently asked questions

### How do I file Indiana sales tax online?

Through INTIME, the Indiana Department of Revenue's portal. Select Form ST-103 for the period, enter your sales, exemptions, and any excluded sales, and pay online. Indiana requires businesses to file and pay sales tax electronically.

### What form do I use to file Indiana sales tax?

Form ST-103, the Sales and Use Tax Voucher, filed through INTIME.

### When is Indiana sales tax due?

Monthly returns are due on the 20th of the month after the period if your average monthly tax for the preceding year was more than $1,000, and on the 30th day after the period if it was $1,000 or less. A due date on a weekend or holiday moves to the next legal business day.

### Do I have to file if I had no sales?

Yes. A return must be filed even when no tax is due, unless the Indiana tax account has been properly closed.

### What is the economic nexus threshold in Indiana?

Gross revenue from sales into Indiana above $100,000 in the current or preceding calendar year. Indiana removed its 200-transaction threshold effective January 1, 2024.

### What is the penalty for filing Indiana sales tax late?

10% of the tax due or $5, whichever is greater, for a late payment, plus interest from the due date. The rate is 7% for 2026.

## Sources

Checked September 29, 2026.

- Indiana Department of Revenue, [Business FAQ](https://www.in.gov/dor/i-am-a/business-corp/business-faq/)
- Indiana Department of Revenue, [Sales tax](https://www.in.gov/dor/i-am-a/business-corp/sales-tax/)
- Indiana Department of Revenue, [Instructions for Completing Form ST-103](https://www.in.gov/dor/files/st-103inst.pdf)
- Indiana Department of Revenue, [Sales Tax Information Bulletin #70, Farm Markets](https://www.in.gov/dor/files/sib70.pdf) (filing schedule and due dates for new merchants)
- Indiana Department of Revenue, [Sales Tax Information Bulletin #83, Gasoline Use Tax](https://www.in.gov/dor/files/sib83.pdf) (collection allowance schedule for sales tax and gasoline use tax)
- Indiana Department of Revenue, [Sales Tax Information Bulletin #89, Remote Sellers and Marketplace Facilitators](https://www.in.gov/dor/files/sib89.pdf)
- Indiana Department of Revenue, [Remote sellers](https://www.in.gov/dor/i-am-a/business-corp/remote-sellers/)
- Indiana Department of Revenue, [INTIME](https://www.in.gov/dor/resources/online-services/intime/)
- Indiana Department of Revenue, [Departmental Notice #3, Interest Rates](https://www.in.gov/dor/files/reference/dn03.pdf)
- Indiana Department of Revenue, [Rates, fees, and penalties](https://www.in.gov/dor/resources/tax-rates-and-reports/rates-fees-and-penalties/)