Connecticut Income Taxes

efile Connecticut tax return
"The Constitution State"

Connecticut individual income IRS tax deadlines postponed to June 17, 2024, for:

  • Individual federal income tax returns incl. payments normally due on April 15, 2024
  • Tax year 2023 contributions to IRAs and HSA accounts for eligible taxpayers normally due on 4/15/2024
  • Tax year 2024 Quarterly estimated income tax payments normally due on Jan. 16 and April 15, 2024.

Prepare and e-file your current year Connecticut state tax return - resident, nonresident, or part-year resident returns - together with your IRS return now via

  • State return only regulations: Per IRS and Connecticut state tax agency regulations - not - you can NOT just prepare and e-file a state return (with the exception of California) without also e-filing the IRS return on the same platform. If you have filed your federal return already, you can prepare a Connecticut state return on and then download, print, sign, and mail it in. See instructions on how to ONLY prepare and not also e-file Connecticut and/or other state tax returns.
  • Get your CT taxed filed online with your IRS return on

CT Tax Help and Resources

Connecticut State Income Tax Rate: 6.99%
Estimate your CT Income Taxes now
Compare other state income tax rates.
Prepare only a CT state return without an IRS return.
See step-by-step instructions on how to only prepare and download - not e-file - state returns on
Where Is Your Connecticut Tax Refund Money?
Step 1: Sign into your account and check acceptance by the tax agency.
Step 2: Check your Connecticut Tax Refund Status.
Where Is Your IRS Refund?
Step 1: Sign into your account and check acceptance by the IRS.
Step 2: Check your IRS tax refund status.
Connecticut Income Tax Extension
Connecticut Income Tax Amendment
How to Correct a Rejected Tax Return
If your CT tax return was rejected by the CT tax agency - not - see instructions on how to correct a rejected Connecticut tax return.
How to Pay Income Taxes
Step 1: See options on how to best pay your CT income taxes.
Step 2: Learn your IRS payment options.
Connecticut, IRS Late Filing, Tax Payment Penalties
1. Outstanding Tax Balance after Original Deadline: 10% penalty and 1% interest rate for each month or fraction of a month until payment is made.
4. IRS Penalties: Calculate and estimate your potential IRS income tax return penalties.
CT Tax Return Mailing Addresses
Find various Connecticut Mailing Addresses for tax returns, tax amendments, and tax payments.
Connecticut Income Tax Brackets
Connecticut Income Tax Forms
Connecticut Unemployment Benefits
Unemployment benefits are taxed to the same extent as federal law in Connecticut.

Start Federal and Connecticut Tax Returns

e-File These Connecticut State Tax Forms

Prepare and e-File these state forms for the Current Tax Year in conjunction with your Federal and State Income Tax Return. As you proceed through the tax interview on, the application will select the correct state forms for you. You can also select tax forms individually. All these forms will then be e-filed by you to the State Tax Agency. Instructions on how to only prepare a state income tax return.

CT Tax Form Current Tax Year
CT-1040ES - Connecticut Estimated Connecticut Income Tax Payment Coupon for Individuals
CT-1040 EXT - Application for Extension of Time to File Connecticut Income Tax Return for Individuals
CT-1040NR/PY - Connecticut Non-Resident and Part Year Resident
CT-1040V - 2020 Connecticut Electronic Filing Payment Voucher
CT-1040X - Amended Connecticut Income Tax Return for Individuals
CT-2210 - Underpayment of Estimated Income Tax by Individuals, Trusts, and Estates
CT-6251 - Connecticut Alternative Minimum Tax Return - Individuals
CT-8822 - Change of Address
CT-8857 - CT Request for Innocent Spouse Relief
Form CT-1040 - Connecticut Resident Income Tax Return
Form OP-186 - Connecticut Individual Use Tax Return
Schedule CT-EITC - Connecticut Earned Income
Supplemental Schedule CT-1040WH - Connecticut Income Tax Withholding

Due to IRS and state tax agency tax data sharing and validation requirements, you can only e-file a state income tax return while also e-filing a federal income tax return. This is not an created policy, but all online tax web sites have to adhere to this IRS/state issued tax data sharing policy. You can however prepare all 44 state income tax returns on if you have already e-filed or filed your IRS return. See instructions on how you can ONLY prepare and file state income tax return(s). Only on can you prepare, file or e-file unlimited state tax returns for one low price and not pay for each state return like you would do on H&R Block® vs. TurboTax®. Dare to Compare Now.