Connecticut Filing Due Date: Individual income tax returns are due by April 15, in most years — or by the 15^th day of the 4^th month following the end of the taxable year (for fiscal year filers).

Extended Deadline with Connecticut Tax Extension: Connecticut offers a 6-month extension, which moves the filing deadline to October 15 (for calendar year filers).

Connecticut Tax Extension Form: In order to get more time to file, your Connecticut extension request must be submitted by the original due date of your return. To request a Connecticut tax extension, file Form CT-1040 EXT with the Department of Revenue Services. Or, you can request an extension electronically using WebFile through the online Taxpayer Service Center (TSC): www.ct.gov/drs/TSC

Connecticut Extension Payment Requirement: An extension of time to file is not an extension of time to pay your Connecticut income tax. All state tax payments are due by the original deadline of the return. Any tax not paid by the proper due date will be subject to penalties and interest. You can make a Connecticut extension payment with Form CT-1040EXT, or pay electronically using Connecticut’s Taxpayer Service Center (TSC): www.ct.gov/drs/TSC

Connecticut Tax Extension Tip: If you have a valid Federal tax extension (IRS Form 4868) and you owe zero Connecticut income tax, you will automatically receive a Connecticut tax extension. In this case, you do not need to file a separate Connecticut request.

Note that taxpayers who do not have an approved Federal extension and want to obtain a Connecticut-only extension are required to provide “good cause” for their state extension request on Form CT-1040 EXT.