Highway Use Fee - Registration is now open for certain carriers to register for the new Connecticut Highway Use Fee - Click here for more information.

IMPORTANT INFORMATION - the following tax types are now available in myconneCT: Individual Income Tax, Attorney Occupational Tax, Unified Gift and Estate Tax, Controlling Interest Transfer Tax, and Alcoholic Beverage Tax. - Click here for the latest information.

Registering and Reporting Requirements - Nexus

Corporation Business Tax

Who Must Register?

Every corporation (or association taxable as a corporation) that carries on business or has the right to carry on business in Connecticut must register with the Department of Revenue Services.

Responsibilities Once You Register


Who Must File Form CT-1120?
Form CT-1120, Connecticut Corporation Business Tax Return, must be filed by every corporation (or association taxable as a corporation) that carries on business or has the right to carry on business in Connecticut. Any corporation dissolved or withdrawn from Connecticut during its fiscal year is subject to the corporation business tax up to the date of dissolution or withdrawal.

Filing Form CT-1120

When to File Form CT-1120

Every corporation must file a return on or before the fifteenth day of the month following the due date of the company's corresponding federal income tax return for the income year (May 15 for calendar year taxpayers). Corporations with a tax year ending June 30 must file a return on or before October 15. The return will be considered timely if the date shown by the U.S. Postal Service cancellation mark is on or before the due date of the return. If the return is filed late, the corporation will be subject to penalties and interest.

Sales and Use Tax

General Information on Who Must Register

The sales and use tax applies to the retail sales of most goods, the lease or rental of goods and sales of certain services. The sales tax is assessed on the total amount you charge for goods and services. The use tax is assessed on the purchase price charged for goods and services when the seller of those goods or services does not collect sales tax from the purchaser.

If you are engaged in selling goods or services in this state you must obtain a Sales and Use Tax Permit before you begin your business. If your business is located outside of Connecticut, see Sales and Use Tax - Nexus.

Every person desiring to engage in or conduct business as a seller within this state must register by completing REG-1, Business Taxes Registration Application.

This registration requirement applies to manufacturers, wholesalers and retailers of goods.

Any business that sells a taxable service in Connecticut must obtain a Sales and Use Tax Permit. You must register whether the business is organized as a sole proprietorship, partnership, corporation, limited liability partnership, or limited liability company, regardless of the amount of tax collected or goods and services sold.

If you are purchasing an existing business, you may not use the prior owner's Sales and Use Tax Permit. You must register to obtain your own permit. You should also be aware that a purchaser of an existing business can be held liable as a successor for any unpaid tax liabilities of the previous owner. Review IP 2018(10), Successor Liability and Request for Tax Clearance.

Responsibilities Once You Register

DRS issues a Sales and Use Tax Permit to a business that registers for sales and use tax in Connecticut. A permit is required for each location where a business operates and must be displayed at each business location. The permit expires every two years and will be automatically renewed on the anniversary date of its issuance, provided there are no delinquencies on the account. There is no renewal fee. A new permit is issued when the renewal notification is returned.

If a Sales and Use Tax Permit is lost or destroyed, you may obtain a new permit by writing to the E-Services/Reg Apps with a request for a copy of your permit. To change a name or address on a permit, write to the Registration Section or show the change on the front of the sales and use tax return. The mailing address for correspondence is:

Department of Revenue Services
E-Services/Reg Apps
450 Columbus Blvd., Ste 1
Hartford CT 06106-5032

In general, when you register, you will be set up to file sales and use tax returns on a monthly basis. Form OS-114 is due on or before the last day of the month following the end of the filing period.  Remember: even if you did not make any sales for the period, you must file the return.

For quarterly filers, the reporting periods and due dates of the return are:

Reporting Periods

Due Dates

January 1 - March 31 April 30
April 1 - June 30  July 31
July 1 - September 30  October 31
October 1 - December 31 January 31

If your sales tax liability is less than $1,000 for the calendar year, the DRS will notify you in writing that you are being changed to annual filing status.  The due date for annual filers is January 31 for the previous calendar year's sales.

If your sales tax liability is more than $4,000 for the calendar year, the DRS will notify you in writing that you are being changed to monthly filing status.  The due date for monthly returns is the last day of the following month.  For example, the return for March will be due on or before the last day of April.

If the due date falls on a Saturday, Sunday or Legal Holiday, the return is due on the next business day.  

All taxpayers (except annual filers) must file electronically and make a tax payment by electronic funds transfer.  Use the TSC, our simple, secure and free, Internet filing system to file returns for sales tax, withholding tax and room occupancy tax returns.  Visit our TSC webpage for more information.

DRS myconneCT will replace the Taxpayer Service Center (TSC) as part of a multi-year, multi-phase project. Each year, additional tax types will be transitioned out of the TSC and into myconneCT. Using myconneCT, taxpayers will be able to file taxes, make payments, view filing history, and communicate with the agency simply and more efficiently on virtually any mobile device, including laptops, tablets, and smartphones, 24 hours a day, 7 days a week. For updated information as to the progress of this project and the transition schedule for specific taxes, please visit the DRS website at portal.ct.gov/DRS-myconneCT

Annual filers will receive Form OS-114, Connecticut Sales and Use Tax Return, by mail at the end of each filing period.  Annual filers are required to file a timely return even if you do not receive one in the mail. Form OS-114 can also be found on the DRS website by selecting the Forms link and then selecting Sales Tax.  Annual filers can also file their Sales and Use Tax return on the TSC.

Filing Form OS-114, Sales and Use Tax Return

To be timely, a return must be filed on or before the due date for filing the return (if the return is mailed, the U.S. Postal Service cancellation mark must show a date that is on or before the due date of the return). The due date for returns is the last day of the month following the end of the reporting period. If the last day of the month is a Saturday, Sunday, or legal holiday, the return is due on the next business day.

Reporting Requirements

If you file your return late and a payment of tax is due, you will be subject to additional charges for penalty and interest. The penalty is 15% of the tax due or $50, whichever is greater. Interest is computed at the rate of 1% per month or fraction of a month.

A sales and use tax return must be properly completed and include every sale of goods or services, every lease or rental of goods, and every purchase subject to use tax made during the filing period. The business must report the deductible items on the return which includes nontaxable sales and tax exempt sales. You must file a return even if you made no sales or purchases subject to use tax during the reporting period and no taxes are due. If no sales were made and no purchases were made that are subject to use tax, you should enter zero sales and zero taxes due.

Withholding Tax for Connecticut

Who Must Register?

Anyone who maintains an office or transacts business in Connecticut and who is considered an employer for federal withholding purposes must withhold Connecticut income tax, whether or not the payroll department is located in Connecticut. Special rules apply to payers of nonpayroll amounts and payers of compensation to professional athletes and entertainers. Visit our Employer's Page for more information.

Responsibilities Once You Register

Employers are required to file all withholding forms and remit all withholding payments electronically.

Remit the Connecticut income tax withholding to DRS according to your remitter classification.  Remitter classifications are quarterly, monthly or weekly. Most new employers will be classified as quarterly remitters. DRS will notify you by mail of your new payment frequency if the prior classification has changed.

On or before April 30, July 31, October 31, and January 31

  • File Form CT-941, Connecticut Quarterly Reconciliation or Withholding, (even if no tax is due).

By January 31

  • Provide a federal Form W-2, Wage and Tax Statement to each employee to whom Connecticut wages were paid during the preceding calendar year. 

  • File Form CT-W3, Connecticut Annual Reconciliation of Withholding, together with every "state copy" of federal Form W-2 reporting Connecticut wages paid to employees during the prior calendar year.

If the due date falls on a Saturday, Sunday or legal holiday, the next business day will be the due date.

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How To Register

To register a business, complete REG-1, Business Taxes Registration Application. Form REG-1 is also used to register for most other state business taxes administered by the Department of Revenue Services. In completing Form REG-1 you must furnish a general description of your business activities. If your business is a sole proprietorship you must furnish your Social Security Number. If it is a partnership, corporation, limited liability company or limited liability partnership, you must furnish the company's Federal Employer Identification Number (FEIN) and the Social Security Numbers, names and addresses of the partners or officers.  If there are more than three partners or officers, attach a list of the remaining names and Social Security Numbers to Form REG-1.

Use Form REG-1 to register for Admissions and Dues Tax, Business Entity Tax, Business Use Tax, Cigarette Tax (over the counter retail sales), Corporation Business Tax, Dry Cleaning Surcharge, Income Tax Withholding, Motor Vehicle Rental Surcharge, Room Occupancy Tax, Tourism Account Surcharge on the Rental/Leasing of Passenger Motor Vehicles, Unrelated Business Income Tax, Utility Companies Tax, as well as for the Sales and Use Tax.

You may register either online, by mail or in person at the Department's Hartford office. If you apply in person, you will be issued a temporary seller's permit and assigned a Connecticut Tax Registration Number that same day. Once you have the temporary seller's permit you may begin making sales. You will be mailed your permanent Sales and Use Tax Permit which will be valid for two years. You may apply in person at the main office in Hartford. If you register by mail, it will take approximately two to three weeks to receive the permit.

REMEMBER: No sales may be made until the Sales and Use Tax Permit (or the temporary seller's permit) is issued.

There is a $100 fee (an additional $50 if the retail sale of cigarettes is involved) to register for a Sales and Use Tax Permit, payable at the time of registration. If you register at our Hartford  office, payment must be made by cash, check or money order. You must bring a photo identification, such as a driver's license with you. The application must be signed by the individual owner, partner, officer of the corporation or another person who has authorization to sign by a Power of Attorney granted by the owner, partner or officer of the corporation.

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