Form CT-1120 EXT — Application for Extension of Time to File Connecticut Corporation Business Tax Return

Department of Revenue Services

State of Connecticut
(Rev. 12/25)
1120EXT 1225W 01 9999
2 0 2 5

Enter Income Year Beginning 

M M - D D - Y Y Y Y

Corporation/Designated Taxable Member name

Form CT-1120 EXT
Application for Extension of Time to File

Connecticut Corporation Business Tax Return and Ending 

M M - D D - Y Y Y Y

Connecticut Tax Registration Number
This return MUST be filed electronically!

Number and street PO Box


# Federal Employer ID Number (FEIN)

DO NOT MAIL paper tax return to DRS.
City, town, or post office State  ZIP code
Request for extension to file Form CT‑1120, Corporation Business Tax Return or Form CT‑1120CU, Combined Unitary Corporation Business
Tax Return. Each corporation must submit payment of any tax due or believed to be due with this application for an extension of time to file, whether or not an application for federal extension has been approved. See instructions.
I request an extension of time to November 15, 2026, to file my Connecticut Corporation Business Tax return for calendar year 2025, or until (MM-DD-YYYY) for fiscal year ending (MM-DD-YYYY).
June 30 year end filers may request a seven-month extension. All others may request a six‑month extension.
A federal extension has been requested on federal Form 7004, Application for Automatic Extension of Time to File Certain Business Income

Check (MM-DD-YYYY) and

Tax, Information, and Other Returns, for calendar year 2025 or fiscal year beginning here (MM-DD-YYYY). If a federal extension has not been filed, explain why you are requesting the Connecticut ending extension:

# Are you filing Form CT‑1120CU? Yes No .00

1. Tentative amount of tax due for this income year; minimum tax $250. See instructions … 1. .00
   1. Surtax: See instructions … 2. .00
   2. Total tax: Add Line 1 and Line 2. Include tax credit recapture, if applicable … 3. .00
   3. Multiply Line 3 by 49.99% (0.4999) See instructions … 4. .00
   4. Multiply the number of taxable members included by $250 … 5. .00
   5. Enter the greater of Line 4 or Line 5 … 6. .00
   6. Tax credit limitation: Subtract Line 6 from Line 3 … 7. .00
   7. Tax credits … 8. .00
   8. Balance of tax payable: Subtract Line 8 from Line 3 … 9. .00
   9. PE credit: See instructions … 10.
   10. Balance of tax payable: Subtract Line 10 from Line 9, but not less than zero ("0") … 11. .00 .00
   11. Payment(s) of estimated tax … 12. .00
   12. Overpayment from prior year … 13. .00
   13. Total payments: Add Line 12 and Line 13 … 14. .00
   14. Amount due with this return: Subtract Line 14 from Line 11 …  15.

Declaration: I declare under the penalty of law that I have examined this return and, to the best of my knowledge and belief, it is true, complete, and correct.

I understand the penalty for willfully delivering a false return or document to the Department of Revenue Services (DRS) is a fine of not more than $5,000, imprisonment for not more than five years, or both. The declaration of a paid preparer other than the taxpayer is based on all information of which the preparer has any knowledge.
Corporate officer's name (print) Corporate officer's signature Date (MM-DD-YYYY)
This return MUST be filed
Sign
Here
Title electronically!
Telephone number
May DRS contact the preparer

Yes No
DO NOT MAIL paper tax return to DRS.
Keep a copy of shown below about this return?
Paid preparer's signature
Paid preparer's name (print) this return for your Firm's name and address records.

Date (MM-DD-YYYY) Preparer's SSN or PTIN

Firm's FEIN Telephone number
Visit us at portal.ct.gov/DRS for more information.

Department of Revenue Services

Form CT-1120 EXT Instructions

State of Connecticut

Use Form CT‑1120 EXT, Application for Extension of Time to File Connecticut Corporation Business Tax Return, to request a six‑month extension (seven-month extension for corporations with a June  30 fiscal year end) to file Form CT‑1120, Corporation Business Tax Return, or Form CT‑1120CU, Combined Unitary Corporation Business Tax Return. It is not necessary to include a reason for the Connecticut extension request if an extension on federal Form 7004, Application for

# Automatic Extension of Time to File Certain Business Income

Tax, Information, and Other Returns, was filed with the Internal Revenue Service.
If federal Form 7004 was not filed, the corporation may apply for an extension to file the Connecticut Corporation Business Tax return if there is reasonable cause for the request.
To get a Connecticut filing extension, the corporation
MUST:

• Complete Form CT‑1120 EXT in its entirety;
• File it on or before the fifteenth day of the month following the due date of the corporation's corresponding federal income tax return for the income year (May 15 for calendar year taxpayers); and
• Pay the amount shown on Line 15.

Form CT‑1120 EXT extends only the time to file the Connecticut Corporation Business Tax return. Form CT‑1120 EXT does not extend the time to pay the amount of tax due.

# When to File Form CT-1120 EXT

Form CT‑1120 EXT is due on or before the fifteenth day of the month following the due date of the corporation's corresponding federal income tax return for the income year (May 15 for calendar year taxpayers).
If the due date falls on a Saturday, Sunday, or legal holiday, the return is considered timely if filed on the next business day.

# Electronic Filing and Payment Requirements

Form CT‑1120 and Form CT‑1120CU must be filed and paid electronically, and all corporations must file and pay their estimated taxes (Forms CT‑1120 ESA, ESB, ESC and ESD) and extension requests (Form CT‑1120 EXT) electronically.
To request a waiver from the electronic filing requirement visit portal.ct.gov/DRS and complete Form DRS‑EWVR, Electronic Filing and Payment Waiver Request.
The following graduated penalty amounts will apply if you fail to remit payments electronically:

• First offense - 10% penalty on the amount of the tax payment, but not more than $2,500;
• Second offense - 10% penalty, but not more than $10,000; and
• Third and subsequent offenses - 10% penalty.

When initiating a payment through your financial institution's online banking system you must verify that your financial institution is sending an EFT, not a check.

Form CT-1120 EXT Instructions (Rev. 12/25)

# Filing and Paying Electronically

File and pay Form CT-1120  EXT electronically using myconneCT. DRS myconneCT allows taxpayers to electronically file, pay and manage state tax responsibilities.
If you file Form CT-1120  EXT using myconneCT at portal.ct.gov/DRS-myconneCT, you must make an electronic payment at that time. After logging into myconneCT, find your tax account on the Summary screen, select the File an Extension link, choose your payment method, and file Form CT-1120 EXT.

• Pay by Direct Payment: Using this option authorizes DRS to electronically withdraw a payment from your bank account (checking or savings) on a date you select up to the due date.
• Pay by Credit Card or Debit Card: You may elect to pay your tax liability using a credit card (American Express®, Discover®, MasterCard®, VISA®) or comparable debit card.

A convenience fee will be charged by the credit card service provider. You will be informed of the amount of the fee and may elect to cancel the transaction. Your payment will be effective on the date that you make the charge.
At the end of the transaction, you will receive a confirmation number for your records. Tax not paid on or before the due date will be subject to penalty and interest.

# Filing and Paying by Mail

If you file by mail, complete this return in blue or black ink only. Do not use staples.
Please note that each form is year specific. To prevent any delay in processing your return, the correct year's form must be submitted to the Department of Revenue Services (DRS).
If you have received a waiver from the electronic payment requirement, make your check payable to Commissioner of Revenue Services. To ensure payment is applied to your account, write "2025 Form CT‑1120  EXT" and the corporation's Connecticut Tax Registration Number on the front of the check. Be sure to sign your check and paper clip it to the front of your return. Do not send cash. DRS may submit your check to your bank electronically.
Mail paper return with payment to:

Department of Revenue Services

State of Connecticut
PO Box 2974

Hartford CT 06104-2974.
Mail paper return without payment to:

Department of Revenue Services

State of Connecticut
PO Box 150406

Hartford CT 06115-0406.

# Interest and Penalty

Interest is assessed at 1% per month or fraction of a month on any underpayment of tax computed from the due date of the return. The penalty for underpayment of tax is 10% of the tax due or $50, whichever is greater. If no tax is due, the Commissioner of Revenue Services may impose a $50 penalty for the late filing of any return or report that is required by law to be filed.
If a request for a filing extension has been granted, a corporation may avoid a penalty for failure to pay the full amount due by the original due date if it pays:

• At least 90% of the tax shown to be due on the return on or before the original due date of the return; and
• The balance due with the filing of Form CT‑1120, or Form CT‑1120CU on or before the extended due date.

# Credit Against Estimated Payments

An overpayment of tax liability for 2025 will be applied against the first installment of estimated tax due in 2026 if the taxpayer timely files a completed Form CT-1120 or Form CT-1120CU and elects to apply an overpayment from 2025 against its 2026 estimated tax.

# Tax Credit Recapture

If the corporation is subject to recapture of tax credits, include the tax credit recapture amount in the total tax for the current income year.
Surtax
Companies whose gross income equals or exceeds $100 million or who file as part of a combined unitary return must pay a surtax of 10% of the tax without regard to credits and tax credit recapture. The surtax does not apply to the minimum tax of $250.

Special Instructions - Combined Unitary Tentative

Corporation Business Tax Return

# The Designated Taxable Member should file one Form

CT‑1120 EXT on behalf of all members of the combined unitary group included in Form CT‑1120CU.
All payments should be made under the Designated Taxable Member's Connecticut Tax Registration Number.
For groups filing their first Form CT‑1120CU in 2025, the group will select a Designated Taxable Member when it files its Form CT‑1120CU. If the parent company does not have nexus in Connecticut, any other member with nexus may be selected as the Designated Taxable Member. If a payment is made by a member other than the Designated Taxable Member, it will be treated as made by the Designated Taxable Member when the combined unitary return is filed. Any extension of time to file approved for any member of the group will be a valid extension of time to file for all members of the group.
Signature
An officer of the corporation must sign this form.

Form CT-1120 EXT Instructions (Rev. 12/25)

Paid Preparer Signature
A paid preparer must sign and date Form CT‑1120 EXT.
Paid preparers must also enter their Social Security Number
(SSN) or Preparer Tax Identification Number (PTIN) and their firm's FEIN in the spaces provided.

Others Who May Sign
Anyone (including attorneys, accountants, and enrolled agents) with a signed Power of Attorney may sign for the corporation in place of a corporate officer.

# Line Instructions

Line 1 - Enter the tax due for the current income year without regard to surtax or recapture. Combined unitary filers aggregate each taxable member's tax and enter the total.
Line 2 - Enter the surtax amount due.
Form CT-1120 filers: If Line 1 is $250, enter zero ("0").
Otherwise, if gross income (from federal Form 1120, Line 11, amount in box at the top of Form CT‑1120) is $100 million or more, multiply Line 1 by 10% and enter the result.
Form CT‑1120CU filers: Each taxable member included in Form CT‑1120CU computes its surtax on a separate company basis. For any taxable member whose tax exceeds $250, multiply the tax by 10% and enter the total of the surtax amounts.
Line 3 - Add Line 1 and Line 2. Include tax credit recapture, if applicable.
Line 4 - Multiply Line 3 by 49.99% (0.4999).
The amount of tax credits allowable against the Corporation Business Tax for any income year generally may not exceed 50.01% of the tax due prior to the application of the tax credits. Certain tax credits that remain after the application of the 50.01% limitation may be further used, complete Form CT-1120K in determination of allowable tax credits.
Each taxable member included in Form CT-1120CU applies tax credits on a separate company basis, which are then aggregated and applied against the combined unitary tax liability.
See Special Notice 2016(1), Combined Unitary Legislation, for more information on tax credit usage by members of a unitary group.
Line 5 - Form CT‑1120 filers, enter $250. Form CT‑1120CU filers, multiply the number of taxable members included in the return by $250 and enter the result.
Line 10 - Enter the amount of Pass-Through Entity (PE) tax credit that will be reported on Form CT‑1120, Schedule C, Line 7. Combined Unitary filers should enter the amount of PE credit the group expects to enter on Form CT‑1120CU, Part III, Line 4. Do not exceed the balance of tax payable reported on Line 9.