Connecticut State Tax Forms

Connecticut residents and individuals with Connecticut-sourced income must file their state income tax returns using forms provided by the Connecticut Department of Revenue Services (DRS).

The state strongly encourages, and in many cases expects, taxpayers to file electronically through its secure online system, myconneCT, which streamlines filing, payment, and communication with the DRS.

Primary Individual Income Tax Forms

Form CT-1040 — Connecticut Resident Income Tax Return
This is the standard income tax return for individuals who were full-year Connecticut residents during the tax year. You must file this form if you meet Connecticut’s filing requirements, such as having Connecticut income tax withheld, making estimated tax payments, or exceeding the state’s gross income thresholds.

Form CT-1040NR/PY — Connecticut Nonresident and Part-Year Resident Income Tax Return
This form is used by individuals who were nonresidents or part-year residents of Connecticut and earned income from Connecticut sources. It ensures that only income attributable to Connecticut is taxed while accounting for residency changes during the year.

Common Associated Forms and Schedules

Depending on your tax situation, you may need to include additional forms or schedules with your return:

• Form CT-1040ES — Estimated Income Tax Payment Voucher
  Used to make quarterly estimated tax payments if you expect to owe more than $1,000 in Connecticut tax and do not have sufficient withholding.
• Form CT-1040X — Amended Connecticut Income Tax Return
  Filed to correct errors or make changes to a previously submitted Connecticut income tax return.
• Form CT-1040 EXT — Application for Extension of Time to File
  Grants additional time to file your return, but does not extend the time to pay any tax owed.
• Form CT-2210 — Underpayment of Estimated Income Tax
  Used to calculate interest due if you did not make sufficient estimated tax payments throughout the year.
• Supplemental Schedule CT-1040WH — Connecticut Withholding Schedule
  Required if you have more than five federal Forms W-2 or 1099 showing Connecticut income tax withheld.
• Schedule CT-EITC — Connecticut Earned Income Tax Credit
  Used to claim the state Earned Income Tax Credit, which is available to eligible low- and moderate-income workers.
• Schedule CT-CHET — CHET 529 College Savings Plan Contributions
  Used to report contributions to the Connecticut Higher Education Trust (CHET) 529 plan, which may qualify for a state income tax deduction.

Where to Find Forms and How to File

All Connecticut tax forms, schedules, and instructions are available directly from the Connecticut Department of Revenue Services (DRS) website.

Benefits of Filing Electronically

• Faster processing and quicker refunds
• Built-in error checks that reduce mistakes
• Secure submission of returns and payments
• Ability to track return status and correspondence
• Easy access to prior filings and payment history

Electronic filing is the most efficient, accurate, and secure way to meet your Connecticut tax obligations and is the preferred method for both residents and nonresidents.