Connecticut Tax

Complete resource guide to Connecticut Taxes.

Connecticut Taxes
Connecticut Personal Income Tax CT DRS
Tax Assistance 860-297-5962
Tax Assistance (Inside CT) 800-382-9463
Forms and Instructions Forms
Residents Tax Forms CT-1040
Party Year and Nonresidents Tax Forms CT-1040NR/PY
IRS Tax Refund Check IRS Tax Refund Status
CT Tax Refund Check CT Tax Refund Status
CT Tax Refund Assistance 860-297-5962
CT Unemployment CT Unemployment
CT Income Tax Due Date April 15
CT Income Tax Extension Form 1040EXT or IRS Form 4868
Connecticut Business Taxes
CT Dept of Revenue – Sales Tax CT Sales Tax
CT Withholding Tax CT Withholding Taxes
CT Dept of Labor CT Unemployment Insurance Tax

Connecticut Tax Filing Requirements

  • Had Connecticut income tax withheld
  • Made estimated tax payments
  • Meet the gross income test
  • Are claiming the Connecticut Earned Income Tax Credit.
Connecticut Tax Filing Required if Gross Income Exceeds
Single $15000
Married Filing Jointly $24000
Married Filing Separately $12000
Head of House $19000
Qualifying Widower $24000

Connecticut State income tax ranges from 3% to 6.99% for the current tax year.

Connecticut Income Tax Forms

  • Form CT-1040,Connecticut Resident Income Tax Return.
  • Schedule CT-EITC, Connecticut Earned Income Tax Credit.
  • Form CT-1040NR/PY, Connecticut Nonresident and Part-Year Resident Income Tax Return.
  • Schedule CT-SI, Nonresident or Part-Year Resident Schedule of Income From Connecticut Sources.
  • Schedule CT-1040AW, Part-Year Resident Income Allocation.
  • Schedule CT-1040BA, Nonresident Business Apportionment Schedule.

Connecticut Income Tax Brackets

CT Tax Bracket Single/MFS Head of House MFJ
3% 0-10000 0-16000 0-20000
5% 10001-50000 16001-80000 20001-100000
5.5% 50001-100000 80001-160000 100001-200000
6% 100001-200000 160001-320000 200001-400000
6.5% 200001-250000 320001-400000 400001-500000
6.9% 250001-500000 400001-800000 500001-1000000
6.99% 500001 and over 800000 and over 1000000 and over

Connecticut Income Tax Extension:

Connecticut allows an automatic extension to October 15 if no additional tax is due and if a federal extension request is filed. If additional tax is due, file Form CT-1040 EXT, Application for Extension of Time to File Connecticut Income Tax Return for Individuals, to request an extension to October 15.

Extension mailing addresses:
Form CT-1040 EXT (No Payment)
Department of Revenue Services, P.O. Box 2976, Hartford, CT 06104-2976

Form CT-1040 EXT (With Payment) 
Department of Revenue Services, P.O. Box 2977, Hartford, CT 06104-2977 

Tax Forms and Payment Mailing Address

Tax forms with payment
Department of Revenue Services
P.O. Box 2977
Hartford, CT 06104-2977

Tax forms without payment
Department of Revenue Services
P.O. Box 2976
Hartford, CT 06104-2976

Form CT-1040V Payment Voucher
Department of Revenue Services
e-File payment voucher 
P.O. Box 2921
Hartford, CT 06104-2921

Connecticut Estimated Tax Information

An underpayment penalty may apply if the balance due is $1,000 or more. The required annual payment is the lesser of:

  • 90% of the income tax shown on the current CT tax return, or
  • 100% of the income tax shown on the previous CT tax return, assuming that return covered a 12-month period.
CT Estimated Payment Period Due Date
1st Quarter (January – March) April 15
2nd Quarter (April – June) June 15
3rd Quarter (July – September) September 15
4th Quarter (October – December) January 15

Connecticut Estimated Tax Payment Mailing Address:

Form CT-1040ES
Department of Revenue Services
P.O. Box 2932
Hartford, CT 06104-2932
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