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Connecticut Income Tax Filing

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CT-1040

CT-1040NR/PY

CT-1040 Line Help

Line 9 Connecticut Alternative Minimum Tax, if any - If you do not have a federal alternative minimum tax liability, enter “0.”  If you have a federal alternative minimum tax liability, complete Form CT-6251, and enter the result here.

Line 13 Adjusted Net Connecticut Minimum Tax Credit, if any - Only enter if you had a CT alternative minimum tax liability in a prior year and did not pay CT alternative minimum tax in current year.

Line 15 Individual Use Tax - If you made purchases online or out-of-state and did not pay sales tax, you may owe CT use tax.  See IP 2016(19) for more information.

Line 18 Connecticut tax withheld from W-2/1099s - If you had Connecticut income tax withheld from wages, pension, unemployment, or other distributions, you must complete the Withholding Worksheet to get credit for the tax withheld. (Do not enter forms if there was no Connecticut tax withheld.)

Line 27 Penalty for late filing - If you pay the tax due after the due date, the penalty is 10% of the tax due.  You may prefer to have DRS calculate the penalty and bill you.

Line 28 Interest for late filing - Interest on late payments is 1% of the amount due per month or fraction of a month.  You may prefer to have DRS calculate the penalty and bill you.

Line 29 Interest on underpayment of estimated tax - For information on this, review CT-2210.  You may prefer to have DRS calculate the penalty and bill you.  NOTE:  This form cannot be completed online in the TSC.  If you are filing it on your own you must mail it to the address on the form.                                              

1040 Schedule 1 - Additions to Federal Adjusted Gross Income  For detailed information on the additions to Federal Adjusted Gross Income, go to the CT-1040 instructions booklet using the link at the top of this page.

1040 Schedule 1 - Subtractions from Federal Adjusted Gross Income For detailed information on the additions to Federal Adjusted Gross Income, go to the CT-1040 instructions booklet using the link at the top of this page.                                                        

Line 42 Refunds of state and local income taxes (from your federal Form 1040, Line 10) Enter only if you were required to enter an amount on Line 10 of federal Form 1040.  If you took the sales tax deductions instead of the income tax deduction on last year's federal income tax return (Schedule A), do not enter anything on Line 42.

Line 48 CHET Contributions Enter your contributions to a CHET account(s). The modification cannot exceed $5,000 for each individual taxpayer or $10,000 for taxpayers filing a joint return (including qualifying widow(er) with dependent child). Enter the CHET account number in the space provided.    

1040 Schedule 2 - Credit for Income Taxes Paid to Qualifying Jurisdictions  If you are a resident of Connecticut and if any part of your income was taxed by a qualifying jurisdiction, you may be able to claim a credit against your Connecticut income tax liability for qualifying income tax payments you have made.  You must complete Schedule 2 to claim the credit.  For more information, go to the CT-1040 instructions booklet using the link at the top of this page.    

1040 Schedule 3 - Credit for Property Taxes Paid on Your Primary Residence and/or Motor Vehicle  You may take credit against your Connecticut income tax liability for property tax payments you made on your primary residence or privately owned or leased motor vehicle, or both, to a Connecticut political subdivision. Generally, property tax bills due and paid during the year covered by this return qualify for this credit. This includes any installment payments you made by December 31 of that year that were due in that year and any installments you prepaid during that year that were due in the next year. Supplemental property tax bills that were due during that year or the following year also qualify if paid by December 31. However, the late payment of any property tax bills or the payment of any interest, fees, or charges related to the property tax bill do not qualify for the credit.   

1040 Social Security Benefit Adjustment Worksheet  If you receive Social Security benefits subject to federal income tax, you may reduce or eliminate the amount of your benefits subject to Connecticut income tax. (Parties to a civil union recognized under Connecticut law must recompute their federal adjusted gross income as if their filing status for federal income tax purposes were married filing jointly or married filing separately.)  For more information, go to the CT-1040 instructions booklet using the link at the top of this page.         

1040 Withholding Worksheet  For each federal Form W-2, W-2G, or 1099 where Connecticut income tax was withheld, enter the required information in the boxes provided on the worksheet.  (If Connecticut income tax was not withheld, do not enter information from that form.) 

Select "add W-2/1099-R" if you have more than one W-2/1099-R form with Connecticut tax withheld. Select "delete" to remove an existing W-2/1099-R form that was entered in error. Select "back" to remove all entries and return to page 2 of the CT-1040. After completing all of your W-2/1099 entries, select "next" to accept all values and continue filing.

CT-1040NR/PY Line Help

Residency Status Rules:  Review the information on residency status on page 7 of the CT-1040NR/PY instructions booklet.                                       

Line 6 Income from Connecticut sources For information, see page 8 of the CT-1040NR/PY instructions booklet.

Line 9 Line 6 divided by Line 5 - If Line 6 is equal to or greater than Line 5, enter 1.0000.

Line 11 Credit for income taxes paid to qualifying jurisdictions during resident portion of taxable year - If you paid taxes to another state while living in Connecticut, because, for example, you worked in that state, you may be able to claim a credit for taxes paid to that state.

Line 13 Connecticut Alternative Minimum Tax - If you do not have a federal alternative minimum tax liability, enter “0.”  If you have a federal alternative minimum tax liability, complete Form CT-6251, and enter the result here.

Line 15 Adjusted Net Connecticut Minimum Tax Credit - Only enter if you had a CT alternative minimum tax liability in a prior year and did not pay CT alternative minimum tax in current year.

Line 17 Individual Use Tax - If you made purchases online or out-of-state and did not pay sales tax, you may owe CT use tax.  See IP 2016(19) for more information.

Line 20 Connecticut tax withheld from W-2/1099s - If you had Connecticut income tax withheld from wages, pension, unemployment, or other distributions, you must complete the Withholding Worksheet to get credit for the tax withheld. (Do not enter forms if there was no Connecticut tax withheld.)

Line 29 Penalty for late filing - If you pay the tax due after the due date, the penalty is 10% of the tax due.  You may prefer to have DRS calculate the penalty and bill you.

Line 30 Interest for late filing - Interest on late payments is 1% of the amount due per month or fraction of a month.  You may prefer to have DRS calculate the penalty and bill you.

Line 31 Interest on underpayment of estimated tax - For information on this, review CT-2210.  You may prefer to have DRS calculate the penalty and bill you.                                           

1040NR/PY Schedule 1 Additions to Federal Adjusted Gross Income  For detailed information on the additions to Federal Adjusted Gross Income, go to the CT-1040NR/PY instructions booklet using the link at the top of this page.    

1040NR/PY Schedule 1 Subtractions from Federal Adjusted Gross Income For detailed information on the additions to Federal Adjusted Gross Income, go to the CT-1040NR/PY instructions booklet using the link at the top of this page.                              

Line 45 Refunds of state and local income taxes (from your federal Form 1040, Line 10) - Enter only if you were required to enter an amount on Line 10 of federal Form 1040.  If you took the sales tax deductions instead of the income tax deduction on last year's federal income tax return (Schedule A), do not enter anything on Line 45.

Line 50 Enter your contributions to CHET accounts. The modification cannot exceed $5,000 for each individual taxpayer or $10,000 for taxpayers filing a joint return (including qualifying widow(er) with dependent child). Enter the CHET account number in the space provided.           

1040NR/PY Schedule 2 - Credit for Income Taxes Paid to Qualifying Jurisdictions

If you are a part-year resident of Connecticut and if any part of your income earned during the residency portion of your taxable year was taxed by a qualifying jurisdiction, you may be able to claim a credit against your Connecticut income tax liability for qualifying income tax payments you have made.

Nonresidents may not claim a credit for income taxes paid to other jurisdictions.

1040NR/PY Social Security Benefit Adjustment Worksheet

If you receive Social Security benefits subject to federal income tax, you may reduce or eliminate the amount of your benefits subject to Connecticut income tax. (Parties to a civil union recognized under Connecticut law must recompute their federal adjusted gross income as if their filing status for federal income tax purposes were married filing jointly or married filing separately.)  For more information, go to the CT-1040NR/PY instructions booklet using the link at the top of this page.           

1040NR/PY Withholding Worksheet

For each federal Form W-2, W-2G, or 1099 where Connecticut income tax was withheld, enter the required information in the boxes provided on the worksheet.  (If Connecticut income tax was not withheld, do not enter information from that form.)

Select "add W-2/1099-R" if you have more than one W-2/1099-R form with Connecticut tax withheld. Select "delete" to remove an existing W-2/1099-R form that was entered in error. Select "back" to remove all entries and return to page 2 of the CT-1040NR/PY. After completing all of your W-2/1099 entries, select "next" to accept all values and continue filing.                          

1040NR/PY Schedule CT-1040AW

Part-Year Residents Only:  You must first complete Schedule CT-1040AW to determine your income from Connecticut sources. Add the amounts in Columns B and D for each line and transfer the total to the corresponding line of Schedule CT-SI.      

1040NR/PY Schedule CT-SI

Nonresidents: Report in Schedule CT-SI, Part 1, all items of income you received from Connecticut sources with modifications as described in the CT-1040NR/PY instructions booklet using the link at the top of this page. Report in Schedule CT-SI, Part 2, adjustments directly related to the income items in Part 1.

Part-Year Residents: The information on this schedule is your Connecticut source income based on the figures you entered on the Schedule CT-1040AW.