# How to File Kansas Sales Tax Online in 2026

Canonical: https://trykintsugi.com/blog/how-to-file-kansas-sales-tax-online
Published: 2026-09-07

How to file Kansas sales tax in the Customer Service Center: Form ST-36, due dates on the 25th, zero returns, ACH payment, penalties, and interest.

Kansas sales tax is filed online through the **Kansas Customer Service Center** (KCSC), the Department of Revenue's portal, on the **Retailers' Sales Tax Return (Form ST-36)**. Monthly, quarterly, and annual returns are all due on the 25th of the month after the reporting period, and a return is required every period, even with no sales. The Department requires businesses to file sales tax returns electronically.

This guide covers who files and how often, how to file in the Customer Service Center, how to handle Kansas's destination-based local rates, how to report no sales, how to amend a return, how to pay, 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 [Kansas Department of Revenue](https://www.ksrevenue.gov/efilingmandate.html) before you file.

## Kansas sales tax filing at a glance

- **Who administers it:** Kansas Department of Revenue.
- **Online portal:** Kansas Customer Service Center, at [kdor.ks.gov](https://www.kdor.ks.gov/Apps/kcsc/login.aspx). Filing and payment are free.
- **Return:** Retailers' Sales Tax Return, Form ST-36. Out-of-state remote sellers report Kansas tax on a Retailers' Compensating Use Tax return instead.
- **Filing frequency:** Annual, quarterly, or monthly, based on annual tax due.
- **Due dates:** The 25th of the month after the reporting period. Annual filers file by January 25.
- **Zero returns:** Required every reporting period.
- **Payment:** ACH debit, ACH credit, credit card through third-party vendors, or wire transfer.
- **Economic nexus:** More than $100,000 in cumulative gross receipts from sales to Kansas customers in the current or preceding calendar year.

## Who has to file, and how often

Retailers registered with the Department of Revenue file a sales tax return for each assigned period. Kansas's economic nexus rule for out-of-state sellers is in the Department's Notice 21-17. A seller with no other Kansas presence becomes a "retailer doing business in this state" when it has more than $100,000 of cumulative gross receipts from sales to Kansas customers in the current or immediately preceding calendar year. Gross receipts include all sales to Kansas customers, whether taxable or exempt. The Department also states that a remote seller registers and remits Kansas retailers' compensating use tax. Our [Kansas sales tax guide](/sales-tax-guides/usa/kansas) covers registration and nexus in more detail. For product-level examples, see our posts on [Kansas clothing sales tax](/blog/kansas-clothing-sales-tax) and [Kansas sales tax exemptions](/blog/kansas-sales-tax-exemption).

Sellers that only sell through a marketplace facilitator are treated differently from other sellers under the Department's marketplace notices, so check those notices if you sell on marketplaces as well as your own site.

Your filing frequency depends on the volume of your retail business. The Department's Publication KS-1510 lists these guidelines, set by K.S.A. 79-3607:

| Frequency | Annual tax due | Due date |
| --- | --- | --- |
| Annual | $0 to $1,000 | January 25 of the following year |
| Quarterly | $1,000.01 to $5,000 | April 25, July 25, October 25, and January 25 |
| Monthly | $5,000.01 and over | The 25th of the following month |

Your first-year frequency is based on the estimated tax liability you reported on your business tax application. After that, the Department reviews frequency annually, and you can also ask to change it. Businesses that are seasonal file monthly during their period of operation.

## Before you start: get into the Customer Service Center

You need to be registered with the Department of Revenue before you can file; our [sales tax permit](/blog/sales-tax-permit) overview explains the process. To use the Customer Service Center, you create a login ID and password and then attach each business tax account. Each tax account has a unique access code, which you enter once to bind the account to your login. To get an access code, call 785-368-8222 or email the Department's business tax e-services team. You also need your EIN and internet access.

Before filing, gather your gross sales for the period, sales broken out by the Kansas jurisdiction where the customer receives the item, and records for any deductions you claim, such as resale sales supported by a Kansas resale exemption certificate. For wholesale sales, see our [Kansas resale certificate](/resale-certificates/kansas) guide for what to collect from buyers.

## Step-by-step: filing a Kansas return in the Customer Service Center

1. **Log in to the Customer Service Center** and open your sales tax account.
2. **Select the return and period.** Choose the sales tax return for the month, quarter, or year you are filing. To correct an earlier period, choose the amended (or additional) return option instead of the original.
3. **Enter gross sales by jurisdiction.** Gross sales are total sales in the period, taxable and nontaxable, without the sales tax you collected. Report the gross receipts sourced to each city and county where customers received items.
4. **Enter deductions.** Record deductions such as sales for resale, returned goods, and sales to exempt entities, each backed by the required documents. Do not leave a required line blank; enter 0 if there is nothing to report.
5. **Verify Part I and calculate.** Check the amounts the system calculates for each jurisdiction.
6. **Choose a payment option and submit.** The Department's guide lists ACH debit, ACH credit, or check with voucher on the return. Verify your entries, then submit. The system gives immediate confirmation that the return was filed.

Filing in Kansas 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).

## Local and destination-based rate pitfalls

Kansas requires destination-based sourcing. The Department says sales are generally sourced to the location where the purchaser receives the item, and retailers who ship or deliver items must collect the local sales tax in effect where delivery is made. Rates change by city and county, so applying one rate to every sale leads to under- or over-collection. The Department offers a sales tax rate locator on its website, and its local rate pages list changes by quarter. Our [Kansas sales tax calculator](/us-sales-tax-calculator/kansas) shows current rates by location. The Department also lists exceptions to the general rule for categories such as leases, telecommunications, and repair shops, so check its sourcing page for those.

## Due dates and the weekend rule

Kansas sales tax returns are due on the 25th of the month following the end of the reporting period, and you can see them alongside other states on our [Kansas sales tax due dates](/sales-tax-due-dates#kansas) page:

| Period | Due date |
| --- | --- |
| Monthly | The 25th of the following month (a March return is due April 25) |
| Quarter 1 (January to March) | April 25 |
| Quarter 2 (April to June) | July 25 |
| Quarter 3 (July to September) | October 25 |
| Quarter 4 (October to December) | January 25 |
| Annual | January 25 of the following year |

The Department's guidance says electronic payments must settle on or before the due date. The Department pages we reviewed do not spell out what happens when the 25th falls on a weekend or state holiday, so confirm the treatment with the Department, and consider filing and paying early, before relying on a later date.

## Filing a zero return

You must file even if you had no activity. The Department's guide says you must file an electronic return for each reporting period, even if no sales or taxable purchases were made, and that failing to file results in a notice from the Department. Its example has a quarterly filer with no retail sales entering "0" on the Gross Sales line.

## Amending a return

To correct an error, file an amended return for each affected period, using the amended (or additional) return option in the online application. You will be asked to enter the total amount previously paid for the period as a credit. Generally you have three years from the date you filed the original return to file an amended return, and no refund or credit is allowed for a return filed more than three years after its due date.

Kansas distinguishes two types. An amended return replaces everything on the original. An additional return adds to what you already reported for that period. Pick the one that matches your correction. Any additional tax shown on an amended return is due when you file it, and late charges apply from the original due date.

## Payment methods

- **ACH debit:** The Department debits the payment from your bank account through the Customer Service Center. It requires a completed EF-101 authorization, which you complete online.
- **ACH credit:** You initiate the payment through your bank, using the format the Department prescribes.
- **Credit card:** Available through third-party vendors, with a convenience fee based on the amount of tax you are paying.
- **Wire transfer:** Accepted from domestic and foreign banks in American currency; call 785-368-8222 for details.

Electronic payments must settle on or before the due date. State law lets the Secretary of Revenue require electronic funds transfer from taxpayers whose sales tax liability exceeds $45,000 in a calendar year, so confirm which payment method applies to your account.

## Penalties and interest for late payment

The Department's guide says the penalty on a late sales or use tax payment is 1% for each month or portion of a month the payment is late, up to a maximum of 24%. A return filed on time without payment of the tax has the same penalties as a late return.

Interest is charged on the tax due if payment is received after the due date, for each month or fraction of a month, and is not charged on penalty or on interest. The Department's penalty and interest page lists the rate as 8% for January 1 through December 31, 2026, and the rate is reset each calendar year. A returned check carries a $30 fee, plus postage for a registered letter.

If your return is late because of an event beyond your control, you can ask for a penalty waiver by letter that includes your tax account number, the filing period, and a phone number. The Department says the interest due must be paid before a waiver request can be considered, and interest is not subject to waiver.

## Common mistakes to avoid

- **Skipping zero returns.** Every assigned period needs a return, even with no sales.
- **Using one rate for every sale.** Sourcing is by destination, so use the rate where the customer receives the item.
- **Including sales tax in gross sales.** Gross sales should exclude the tax you collected. If your prices include tax, divide by 1 plus the tax rate.
- **Paying after the due date.** A return filed without payment is penalized like a late return.
- **Counting only taxable sales toward nexus.** Exempt sales count toward the $100,000 threshold.
- **Waiting for a paper form.** The Department stopped distributing paper forms in 2010.

## If you receive a sales tax notice

A missed or late return often leads to a letter. Our [Kansas sales tax notices guide](/notice-hub/usa/kansas) explains what notices from the Kansas 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 Oklahoma sales tax online](/blog/how-to-file-oklahoma-sales-tax-online)
- [How to file Colorado sales tax online](/blog/how-to-file-colorado-sales-tax-online)
- [How to file Minnesota sales tax online](/blog/how-to-file-minnesota-sales-tax-online)

## Let Kintsugi file for you

If you sell in Kansas and other states, [Kintsugi's sales tax filing software](/product/sales-tax-filing-software) prepares and files returns on each state's assigned schedule and remits payment. Monitoring across every US state is free, so you know when you cross a threshold. Filing starts at $75 per filing, 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

### Can I file Kansas sales tax online for free?

Yes. The Department describes the Customer Service Center as free. A convenience fee applies only to credit card payments made through third-party vendors.

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

Retailers' Sales Tax Return, Form ST-36, filed electronically. Out-of-state remote sellers report Kansas tax on a Retailers' Compensating Use Tax return.

### When is Kansas sales tax due?

The 25th of the month after the reporting period. Monthly returns are due the 25th of the following month, quarterly returns on April 25, July 25, October 25, and January 25, and annual returns on January 25.

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

Yes. Kansas requires an electronic return for each reporting period even when no sales or taxable purchases were made. Enter 0 for gross sales.

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

More than $100,000 in cumulative gross receipts from sales to Kansas customers in the current or immediately preceding calendar year, counting taxable and exempt sales.

### What if I miss the deadline?

File and pay as soon as possible. The penalty is 1% per month up to 24%, plus interest, and you can request a penalty waiver if the delay was beyond your control.

## Sources

Checked September 29, 2026.

- Kansas Department of Revenue, [Filing requirements for retailers' sales, compensating use, and withholding tax](https://www.ksrevenue.gov/efilingmandate.html)
- Kansas Department of Revenue, [Pub. KS-1510, Sales Tax and Compensating Use Tax](https://www.ksrevenue.gov/pdf/pub1510.pdf)
- Kansas Department of Revenue, [Pub. KS-1515, Tax Calendar of Due Dates](https://www.ksrevenue.gov/pub1515.html)
- Kansas Department of Revenue, [Penalty and interest](https://www.ksrevenue.gov/pandi.html)
- Kansas Department of Revenue, [Electronic funds transfer information](https://www.ksrevenue.gov/eserveft.html)
- Kansas Department of Revenue, [Notice 21-17, Remote sellers](https://www.ksrevenue.gov/taxnotices/notice21-17.pdf)
- Kansas Department of Revenue, [Information for marketplace facilitators and remote sellers](https://www.ksrevenue.gov/taxmarketplace.html)
- Kansas Department of Revenue, [Destination-based sourcing rules](https://www.ksrevenue.gov/sourcingrules.html)