# How to File Connecticut Sales Tax Online in 2026

Canonical: https://trykintsugi.com/blog/how-to-file-connecticut-sales-tax-online
Published: 2026-08-27

How to file Connecticut sales tax in myconneCT: Form OS-114, due dates, zero returns, payment options, penalties, and interest.

Connecticut sales tax is filed online through **myconneCT**, the Department of Revenue Services (DRS) portal, on the **Connecticut Sales and Use Tax Return (Form OS-114)**. The return is due on or before the last day of the month following the end of your filing period, and DRS says you must file even if you made no sales or owe no tax. Form OS-114 must be filed and paid electronically.

This guide covers who files and how often, how to file in myconneCT, how Connecticut's single statewide rate and special rates work, 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 [Connecticut Department of Revenue Services](https://portal.ct.gov/drs/sales-tax/tax-information) before you file.

## Connecticut sales tax filing at a glance

- **Who administers it:** Connecticut Department of Revenue Services (DRS).
- **Online portal:** [myconneCT](https://portal.ct.gov/drs/myconnect/myconnect). Filing is free, and you can make a payment at the same time you file.
- **Return:** Form OS-114, Connecticut Sales and Use Tax Return. It reports both sales tax and business use tax.
- **Filing frequency:** Monthly, quarterly, or annual, as assigned by DRS.
- **Due dates:** On or before the last day of the month following the end of the filing period.
- **Zero returns:** Required. Businesses report all sales activity even if no sales were made or no tax is due.
- **Payment:** ACH debit, ACH credit, or credit or debit card (a convenience fee applies to cards).
- **Economic nexus:** For out-of-state sellers, 200 or more retail sales into Connecticut and at least $100,000 in gross receipts from sales into Connecticut.

## Who has to file, and how often

You must register with DRS for sales and use tax if you intend to sell, rent, or lease goods, sell a taxable service, or operate a hotel, motel, lodging house, or bed and breakfast in Connecticut. The Department says the permit requirement applies regardless of the number of sales or the amount of tax collected, with an exception for casual or isolated sales. Registration carries a $100 fee. Our [Connecticut sales tax guide](/sales-tax-guides/usa/connecticut) covers registration and nexus in more detail. For product-level examples, see our posts on [Connecticut retail sales tax](/blog/ct-retail-tax) and [Connecticut sales tax on clothing](/blog/ct-sales-tax-on-clothing-under-50).

For out-of-state sellers, the Department's registration page says you must register and obtain a Connecticut Sales and Use Tax Permit if you make retail sales to a destination in Connecticut and, during the 12-month period ending on September 30 immediately before the period for which liability is determined, you make 200 or more retail sales into Connecticut and have at least $100,000 in gross receipts from those sales. Marketplace facilitators and marketplace sellers have their own rules in the Department's guidance (OCG-8), so check it if you sell through marketplaces as well as your own site.

The Department assigns your filing frequency, and Form OS-114 covers a monthly, quarterly, or annual period. The Department's current instructions say the return is due on or before the last day of the month following the end of the filing period, which gives these dates:

| Frequency | Due date |
| --- | --- |
| Monthly | Last day of the following month |
| Quarterly | April 30, July 31, October 31, and January 31 |
| Annual | Last day of the month after the period ends |

The current pages we checked do not publish dollar cutoffs for each frequency, so confirm your assigned frequency and periods in myconneCT or with the Department. The current Form OS-114 instructions say annual filers must file and pay electronically for periods beginning on or after January 1, 2022.

## Before you start: get into myconneCT

You need a Connecticut Tax Registration Number and a Sales and Use Tax Permit before you can file; our [sales tax permit](/blog/sales-tax-permit) overview explains the general process. New businesses can register through myconneCT. To file, create a myconneCT username and password. The Department notes that credentials for its Taxpayer Service Center cannot be used to sign in to myconneCT, so you must create and use myconneCT credentials.

Before filing, gather your gross receipts for the period, your exempt sales itemized by deduction line, and records supporting each deduction. The Department may require certificates from purchasers to support exempt sales, so keep your resale paperwork organized; our [Connecticut resale certificate](/resale-certificates/connecticut) guide covers what to collect from buyers. If you buy goods or taxable services for use in Connecticut without paying Connecticut tax, you report business use tax on the same return.

## Step-by-step: filing Form OS-114 in myconneCT

1. **Log in to myconneCT** and select the option to file a return for your sales and use tax account.
2. **Confirm the period.** Check that the Tax Registration Number, Federal Employer Identification Number, and period end date are correct.
3. **Enter gross receipts.** Report total gross receipts from sales of tangible personal property (Line 1), leasing and renting of tangible personal property (Line 2), and taxable services (Line 3), in the rate column that applies. Include tax-exempt sales in gross receipts and exclude the sales tax you collected.
4. **Enter use tax purchases if any.** Report gross purchases, leases, and services subject to business use tax on Lines 4 through 6.
5. **Itemize deductions.** Nontaxable sales must be itemized on the deduction lines, such as sales for resale or sales through a registered marketplace facilitator. Personal or business expenses are not deductions.
6. **Round to whole dollars.** The instructions say to round cents to the nearest whole dollar.
7. **Review the calculated tax, then pay.** After you complete the return, the system takes you to the payment page, where you can authorize DRS to withdraw payment from your bank account or pay by card on any date up to the due date. You receive a confirmation number, and you can print a copy for your records.

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## Rate pitfalls: one statewide rate, several special rates

Connecticut has no local sales taxes, so one statewide system applies, but not every sale uses the same rate. The Department lists a 6.35% general rate on most goods (including digital goods) and taxable services, with other rates for particular items:

| Rate | Applies to |
| --- | --- |
| 1% | Computer and data processing services, and canned software electronically accessed or transferred for business use |
| 2.99% | Vessels, motors for vessels, trailers for transporting a vessel, and dyed diesel fuel sold by a marine dock for marine purposes |
| 4.5% | Motor vehicle sales to certain nonresident active-duty military members |
| 7.35% | Meals and certain beverages |
| 7.75% | Most motor vehicles over $50,000, jewelry over $5,000, and clothing, footwear, handbags, luggage, umbrellas, wallets, or watches over $1,000 |
| 9.35% | Passenger motor vehicle rentals of 30 consecutive calendar days or less |

Form OS-114 has a separate column for each rate group, so a sale in the wrong column produces the wrong tax. Our [Connecticut sales tax calculator](/us-sales-tax-calculator/connecticut) shows current rates.

## Due dates and the weekend rule

Form OS-114 is due on or before the last day of the month following the end of the filing period. You can see Connecticut alongside other states on our [Connecticut sales tax due dates](/sales-tax-due-dates#connecticut) page. Using the Department's quarterly pattern for new businesses:

| Period | Due date |
| --- | --- |
| Monthly | Last day of the following month (a March return is due April 30) |
| Quarter 1 (January to March) | April 30 |
| Quarter 2 (April to June) | July 31 |
| Quarter 3 (July to September) | October 31 |
| Quarter 4 (October to December) | January 31 |

DRS's electronic filing page says payments must be initiated on or before the due date and that, if the due date falls on a weekend or holiday, the next business day applies. If you mail a paper return under a waiver, it must be postmarked on or before the due date.

## Filing a zero return

You must file even if you had no activity. The Form OS-114 instructions say businesses must file to report all sales activity in Connecticut, even if no sales were made or no tax is due, and the Department's electronic filing page says you must file a return even if no tax is due. The Department's older guide for new businesses (Informational Publication 2002(26)) also says it may impose a $50 penalty for failing to file a required return even when no tax is due. The Department's pages we reviewed do not describe how to complete a zero return line by line, so follow the prompts in myconneCT or contact DRS if you are unsure.

## Amending a return

If you make a mistake or leave something off your return, the Department says you must correct it by filing an amended return. On Form OS-114, you check the Amended Return box and provide the correct figures for the reporting period. If you paid any tax with the original return, enter that amount on Line 11, without penalty or interest. Amended returns can be filed electronically in myconneCT.

An amended return claiming a refund of tax already paid must be filed within three years of the original due date and must include an explanation of the claim. If you are claiming a refund of tax that you collected from customers, you must refund or credit that tax to the customers. Interest on a late or amended return runs at 1% per month or fraction of a month from the original due date until payment.

## Payment methods

- **ACH debit (recommended):** You authorize DRS to withdraw funds from your bank account by entering your banking information and choosing a payment date in myconneCT.
- **ACH credit:** You initiate the payment through your bank in the ACH CCD+TXP format. To get detailed instructions, complete Form EFT-1, Authorization Agreement for Electronic Funds Transfer.
- **Credit or debit card:** Available in myconneCT. The card processor charges a convenience fee, generally 2.35% of the payment with a minimum charge of $3.95, and the system shows the amount before you confirm.

DRS generally requires you to pay electronically when you file electronically. Only taxpayers who receive a waiver may file a paper return and pay by check; the request for a one-year waiver is Form DRS-EWVR. If you do not remit payment electronically when required, a graduated penalty applies: 10% of the required payment, capped at $2,500 for a first offense and $10,000 for a second offense, with no cap on third and later offenses.

## Penalties and interest

The current Form OS-114 instructions list a penalty for nonpayment or late payment of tax of 15% of the tax due or $50, whichever is greater. DRS's electronic filing page describes late payment penalties as generally 10% or 15% depending on tax type, so confirm the amount that applies to your account. Interest on a late or amended return is 1% per month or fraction of a month from the due date until the date of payment.

If you believe the penalty should be waived because the failure to pay on time was due to reasonable cause and was not intentional or due to neglect, you can request a waiver on Form DRS-PW, through myconneCT for available taxes, by fax, or by mail. You must pay all tax and interest due before the Department will consider the request, and interest cannot be waived. The form must be filed no later than one year from the date the first notice of the penalty was sent or, if the penalty was reported on a return, one year from the date the return was filed.

## Common mistakes to avoid

- **Skipping zero returns.** A return is required for each period, even with no sales.
- **Using the general rate for everything.** Meals, luxury items, and some software have different rates and belong in different columns.
- **Including sales tax in gross receipts.** The instructions say to exclude sales and use taxes from the receipts you report.
- **Missing the electronic payment requirement.** Filing electronically generally means paying electronically, and failing to do so carries its own penalty.
- **Forgetting business use tax.** Purchases for use in Connecticut on which you did not pay Connecticut tax are reported on the same return.
- **Treating an old frequency as current.** Confirm your assigned periods in myconneCT rather than relying on older publications.

## If you receive a sales tax notice

A missed or late return often leads to a letter. Our [Connecticut sales tax notices guide](/notice-hub/usa/connecticut) explains what notices from the Connecticut Department of Revenue Services 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 New Jersey sales tax online](/blog/how-to-file-new-jersey-sales-tax-online)
- [How to file New York sales tax online](/blog/how-to-file-new-york-sales-tax-online)
- [How to file Massachusetts sales tax online](/blog/how-to-file-massachusetts-sales-tax-online)

## Let Kintsugi file for you

If you sell in Connecticut 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 Connecticut sales tax online for free?

Yes. Filing in myconneCT is free, and you can pay at the same time. A convenience fee applies only to credit or debit card payments.

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

Form OS-114, Connecticut Sales and Use Tax Return, filed electronically in myconneCT. It reports both sales tax and business use tax.

### When is Connecticut sales tax due?

On or before the last day of the month following the end of the filing period. For quarterly filers, that pattern gives April 30, July 31, October 31, and January 31. Confirm your assigned frequency with DRS.

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

Yes. The Department says businesses must file Form OS-114 to report all sales activity even if no sales were made or no tax is due.

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

For out-of-state sellers, 200 or more retail sales into Connecticut and at least $100,000 in gross receipts from sales into Connecticut, measured over the 12-month period ending on September 30 before the period for which liability is determined.

### What if I miss the deadline?

File and pay as soon as possible. The Form OS-114 instructions list a late payment penalty of 15% of the tax due or $50, whichever is greater, plus interest of 1% per month or fraction of a month. You can request a penalty waiver, but interest cannot be waived.

## Sources

Checked September 29, 2026.

- Connecticut Department of Revenue Services, [Sales and Use Tax Information](https://portal.ct.gov/drs/sales-tax/tax-information)
- Connecticut Department of Revenue Services, [Form O-88, Instructions for Form OS-114](https://portal.ct.gov/-/media/drs/forms/2026/sut/o-88_0726.pdf)
- Connecticut Department of Revenue Services, [Sales and Use Tax Returns (forms)](https://portal.ct.gov/DRS/DRS-Forms/Sales-Tax-Forms/SUT-Returns)
- Connecticut Department of Revenue Services, [myconneCT](https://portal.ct.gov/drs/myconnect/myconnect)
- Connecticut Department of Revenue Services, [Filing and Paying Connecticut Taxes Electronically](https://portal.ct.gov/drs/myconnect/filing-and-paying)
- Connecticut Department of Revenue Services, [Registering Your Business with DRS](https://portal.ct.gov/drs/businesses/new-business-resource-center/registering-with-drs)
- Connecticut Department of Revenue Services, [Other Helpful Sales and Use Tax Information](https://portal.ct.gov/drs/sales-tax/other-helpful-information)
- Connecticut Department of Revenue Services, [IP 2002(26), Q & A on Sales and Use Tax for New Businesses](https://portal.ct.gov/drs/publications/informational-publications/2002/ip-200226-q--a-on-sales-and-use-tax-for-a-new-businesses)
- Connecticut Department of Revenue Services, [Penalty waiver request, offer in compromise or protest](https://portal.ct.gov/drs/myconnect/penalty-waiver-request-and-offer-of-compromise)
- Connecticut Department of Revenue Services, [Form DRS-PW, Request for Waiver of Civil Penalty](https://portal.ct.gov/-/media/drs/forms/2021/misc/drs-pw_0921.pdf)