An Overview of Connecticut State Personal Income Tax Extension Forms

- Updated March 24, 2021 - 8.00 AM by Admin, ExpressExtension

Does Connecticut support tax extension for personal income tax returns?


Yes, Connecticut requires a separate tax extension Form to be filed with the state department apart from the federal tax extension Form 4868.

What Form does the state of Connecticut require to apply for an extension?


Individuals in Connecticut need to file Form CT-1040 EXT to obtain a 6-month extension of time to file their personal income tax return
with the state.

  • Form CT-1040 EXT- Request For Extension Of Time For Filing Individual Tax Returns

Note: If you have a valid Federal tax extension (IRS Form 4868), you do not need to provide a reason for requesting a Connecticut tax extension.

When is the deadline to file Form CT-1040 EXT with the state of Connecticut?


Connecticut State individual tax extension Form CT-1040 EXT must be filed on or before the 15th day of the 4th month after the tax year ends (April 15 for calendar year filers).

How do I pay my balance due along with the extension Form?


If you owe Connecticut state taxes, you must pay your tax due by the regular due date, or you will be charged with penalties and interest.

To avoid payment delays and for proper application of payment, you can use Connecticut Form CT-1040 EXT to submit payments.

You can also pay tax due online or mail your Form using

Mailing Address for filing Extension with the State


Where do I mail the extension Form CT-1040 EXT?

Department of Revenue Services
PO Box 2977
Hartford CT 06104-2977