NEW Highway Use Fee - Registration is now open for certain carriers to register for the new Connecticut Highway Use Fee - Click here for more information.


IMPORTANT INFORMATION - the following tax types are now available in myconneCT: Individual Income Tax, Attorney Occupational Tax, Unified Gift and Estate Tax, Controlling Interest Transfer Tax, and Alcoholic Beverage Tax. - Click here for the latest information.

1040X help text

CT-1040X Line Help

Line 6  Income from Connecticut sources - [Refer to your previous-filled Form CT-1040NR/PY].  

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

Line 13 If you do not have a federal alternative minimum tax liability, enter “0.”  If you have a federal alternative minimum tax liability, complete a corrected Form CT-6251, write the word "amended" across the top, [enter the result here] and attach it to Form CT-1040X.

Line 15 Credit for property tax paid on your primary residence or motor vehicle, or both. - Only for certain full-year residents who paid property tax to a Connecticut municipality.

Line 17 If changes are being made to your allowable credits, you must complete a corrected Schedule CT-IT Credit, Income Tax Credit Summary. Write the word “Amended” across the top and attach it to Form CT-1040X. You must also attach a corrected Form CT-8801, Credit for Prior Year Connecticut Minimum Tax for Individuals, Trusts, and Estates if the prior year alternative minimum tax credit is being changed. If you are filing a corrected Form CT-8801, write the word “Amended” across the top and attach it to Form CT-1040X

Line 19 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 2019(3) for more information.

Line 21 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 schedule to get credit for the tax withheld. (Only enter information from forms W-2 and 1099 if Connecticut income tax was withheld.)

Line 29 Interest - 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 interest and bill you; if so, leave this amount blank.

1040X Schedule 1 Additions to Federal Adjusted Gross Income

For detailed information on the additions to Federal Adjusted Gross Income, go to the instructions booklet using the link.    

1040X Schedule 1 Subtractions from Federal Adjusted Gross Income        

1040X Schedule 2 - Credit for Income Taxes Paid to Qualifying Jurisdictions

1040X Schedule 3 - Credit for Property Taxes Paid on Your Primary Residence and/or Motor Vehicle  Only for full-year residents who paid property tax to a Connecticut municipality.

You may qualify to take a 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 if you are 65 or older or claim one or more dependents. 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.             

1040X 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. For more information, go to the CT-1040 instructions booklet using the link at the top of this page.    

1040X 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.  (Only enter information from forms W-2 and 1099 if Connecticut income tax was withheld.) 

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

1040X Schedule CT-1040AW

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

1040X 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-sourced income based on the figures you entered on the Schedule CT-1040AW.