Connecticut State Department of Revenue Services

Walk-in services at all DRS branch office locations remain suspended. Email DRS at drs@po.state.ct.us. Email the Priority One Taxpayer Assistance Program: DRSPriorityOne_CollectionsAssist@po.state.ct.us. Please check our Frequently Asked Questions page.

Corporation Tax Forms

Booklet

Name Description Revised Date Due Date
CT-1120 2018 Connecticut Corporation Business Tax Instructions 01/2018 N/A

Business Tax Returns

Name Description Revised Date Due Date
CT-1120 2018 Corporation Business Tax Return 12/2018
CT-1120A Corporation Business Tax Return Apportionment Computation (with instructions) 12/2018
CT-1120 ATT Corporation Business Tax Return Attachment Schedules H, I, and J (with instructions) 12/2018
CT-1120AB Add Back and Exceptions to Add Back of Interest and Intangible Expenses 12/2016
CT-1120K Business Tax Credit Summary 12/2018
CT-1120I Computation of Interest Due on Underpayment of Estimated Tax (with instructions) 12/2018
CT-1120 EXT Application for Extension of Time to File Corporation Business Tax Return (with instructions) 12/2018
CT-1120 ES 2019 Estimated Corporation Business Tax Payment Coupons 12/2018
CT-1120 ES 2018 Estimated Corporation Business Tax Payment Coupons 12/2017
CT-1120X Amended Corporation Business Tax Return 12/2018
CT-1120X Inst. Amended Corporation Business Tax Return Instructions 12/2018 N/A
CT-NAICS NAICS Codes for Principal Business Activity for Connecticut Tax Purposes 05/2004 N/A
CT-1120 CU BOOKLET 2018 Combined Unitary Corporation Business Tax Booklet 12/2018
CT-1120 CU 2018 Combined Unitary Corporation Business Tax Return 12/2018
CT-1120A-CU 2018 Apportionment Computation for Combined Unitary Filers 12/2018
CT-1120CU-NI 2018 Tax on Combined Group Net Income 12/2018
CT-1120CU-MTB 2018 Tax on Combined Group Minimum Tax Base 12/2018
CT-1120CU-MI 2018 Combined Group Member Information 12/2018
CT-1120CU-NCB 2018 Nexus Combined Base Tax Calculation 12/2018

Other Corporation Forms

Name Description Revised Date Due Date
AU-796 Reinstatement Guarantee Declaration for Non-stock Corporations 03/2008 N/A
AU-797 Dissolution Guarantee Declaration for Stock Corporations 04/2008
AU-798 Dissolution Guarantee Declaration for Non-stock Corporations 03/2008
AU-800a Withdrawal Guarantee Declaration for Corporations 03/2008
AU-801 Reinstatement Guarantee Declaration for Stock Corporations 03/2008
CT-1120A-A Corporation Business Tax Return Apportionment Computation-Air Carriers 03/2017
CT-1120 A-BMC Corporation Business Tax Return Apportionment Computation - Motor Bus and Motor Carrier Companies 12/2016
CT-1120 A-BPE Corporation Business Tax Return Apportionment Computation - Broadcasters and Production Entities 12/2016
CT-8822C Corporation Business Tax Change of Address 01/2018
CT-1120 A-CCA Corporation Business Tax Return Apportionment Computation of Income From Credit Card Activities 12/2016
CT-1120 A-FS Corporation Business Tax Return Apportionment Computation of Income from Financial Service Companies Activities 12/2017
CT-1120 A-IRIC Corporation Business Tax Return Apportionment Computation of Income from Services to Regulated Investment Companies 12/2016
CT-1120 A-LP Corporation Business Tax Return Apportionment of Limited Partnership Interests 12/2017
CT-1120 A-SBC Corporation Business Tax Return Apportionment Computation - Securities Brokerage Services 12/2016
CT-1120 PIC Information Return for Passive Investment Companies 12/2018

Credit Forms

Name Description Revised Date Due Date
CT-1120 AT Apprenticeship Training Tax Credit 12/2018
CT-1120 DA Digital Animation Tax Credit 12/2018 N/A
CT-1120 DL Donation of Land Credit 12/2018
CT-1120 EDPC Electronic Data Processing Equipment Property Tax Credit 12/2018
CT-1120 FCIC Fixed Capital Investment Credit 12/2018
CT-1120FP Film Production Tax Credit 12/2018
CT-1120 FPI Film Production Infrastructure Tax Credit 12/2018
CT-1120 GB Green Building Tax Credit 12/2018
CT-1120 HCIC Human Capital Investment Credit 12/2018
CT-1120 HH Historic Homes Rehabilitation Tax Credit 12/2018
CT-1120 HP Historic Preservation Tax Credit 12/2018
CT-1120 HPC Housing Program Contribution Credit 12/2018
CT-1120 HR Historic Rehabilitation Tax Credit 12/2018
CT-1120 HS Historic Structures Rehabilitation Tax Credit 12/2018
CT-IRF Insurance Reinvestment Fund Credit 12/2018
CT-1120 MEC Machinery and Equipment Expenditure Credit 12/2018
CT-1120 PE Pass-Through Entity Tax Credit 12/2018   
CT-1120 RC Research and Experimental Expenditures Credit 12/2018
CT-1120 RDC Research and Development Credit 12/2018
CT-1120SF Service Facility Credit 12/2018
CT-1120 TIC-EZ Manufacturing Facility Credit for Facilities Located in a Targeted Investment Community/Enterprise Zone NOTE: This form replaces Forms CT-1120 CRMC, CT-1120 CRMCEZ, CT-1120 MC and CT-1120 MCEZ 12/2018
CT-UISR Urban and Industrial Site Reinvestment Credit 12/2018
CT-1120 XCH Application for Exchange of Research and Development or Research and Experimental 12/2018
NAA-01 2019 Connecticut Neighborhood Assistance Act (NAA) Program Proposal -Fillable 02/2019
NAA-02 2019 Connecticut Neighborhood Assistance Act Business Application -Fillable 02/2019