Schedule CT-1040WH: Connecticut Income Tax Withholding Supplemental Schedule (2025)
Connecticut · Connecticut DRS · Used for tax years 2025
Schedule CT-1040WH is a supplemental schedule for reporting 2025 Connecticut income tax withholding from Forms W-2, 1099, and Schedules CT K-1. It lists payer or employer identification numbers, applicable Connecticut income amounts, and Connecticut tax withheld, and is attached
Who files this form
Complete the 2025 Schedule CT-1040WH only if you have more than five Forms W-2, 1099, or Schedules CT K-1. Report only forms showing Connecticut income tax withheld.
If you file a joint return, include your spouse’s forms when counting the forms reported on this schedule.
What you'll need
Have your 2025 forms showing Connecticut income tax withholding, including your spouse’s forms if filing jointly. The schedule gives entry instructions for Forms W-2, W-2G, 1099-MISC, 1099-NEC, 1099-R, and Schedule CT K-1.
You will need:
- Your name and Social Security number, plus your spouse’s if filing jointly.
- The employer’s, payer’s, or pass-through entity’s nine-digit federal identification number.
- The Connecticut income and withholding amounts from the forms you report.
- Form CT-1040, CT-1040NR/PY, or CT-1040X, to which you will attach this schedule.
How to file
Complete the schedule in blue or black ink.
- On Line 1, enter the number of 2025 Forms W-2, 1099, and Schedules CT K-1 showing Connecticut withholding that you report on this schedule. Include your spouse’s forms if filing jointly.
- On Line 2, enter the federal identification number in Column A, Connecticut income in Column B, and Connecticut withholding in Column C, using the applicable boxes listed on the schedule. For Schedule CT K-1, leave Column B blank, enter the amount from Part 3, Line 1 in Column C, and check the box to its left.
- Add Column C and enter the total on Line 3. Also enter it on Form CT-1040, Line 18f; Form CT-1040NR/PY, Line 20f; or Form CT-1040X, Line 70f, as applicable.
- Attach the 2025 schedule to the back of your return and submit it to the Connecticut Department of Revenue Services (DRS). Do not use staples.
If you have additional Forms W-2, W-2G, 1099, or Schedules CT K-1, create an identical schedule and attach it to the back of your Connecticut income tax return.
Common mistakes
- Using the wrong year’s schedule. The form warns that the correct year’s form must be attached to avoid processing delays.
- Reporting PE tax credits on this schedule. The instructions say not to do this.
- Including federal withholding or another state’s withholding in Column C. Enter only Connecticut amounts.
- Reporting forms that do not show Connecticut income tax withheld.
- Entering an amount in Column B for Schedule CT K-1 or forgetting to check its box to the left of Column C.
- Using ink other than blue or black, or stapling the schedule to the return.
Questions people ask
Do I include my spouse’s forms on a joint return?
Yes. Include your spouse’s Forms W-2, 1099, and Schedules CT K-1 when counting the forms showing Connecticut withholding reported on this schedule.
Which W-2 boxes do I use?
Enter the employer’s nine-digit EIN from Box b in Column A, Connecticut wages and tips from Box 16 in Column B, and Connecticut income tax withheld from Box 17 in Column C.
How do I report Schedule CT K-1?
Enter the pass-through entity’s nine-digit federal EIN in Column A. Leave Column B blank. In Column C, enter the Connecticut income tax paid on your behalf from Part 3, Line 1, and check the box to the left. Do not use this schedule to report PE tax credits.
What if I need more space?
Create an identical schedule for additional Forms W-2, W-2G, 1099, or Schedules CT K-1 and attach it to the back of your Connecticut income tax return. Do not use staples.
Where does the withholding total go on my return?
Enter the Line 3 total on Form CT-1040, Line 18f; Form CT-1040NR/PY, Line 20f; or Form CT-1040X, Line 70f, depending on which return you file.