Form CT-8379 at a glance
What it is: Form CT-8379, Nonobligated Spouse Claim, is a form of the Department of Revenue Services, State of Connecticut.
Who signs: Signature: The nonobligated spouse must sign this form.
Use Form CT-8379, Nonobligated Spouse Claim, if you are a nonobligated spouse and all or part of your overpayment was (or is expected to be) applied against your spouse's past due State of Connecticut debt (such as child support, student loan, or any debt to any Connecticut state agency); or your spouse's tax debt owed to another state or the IRS; and you want your share of the joint overpayment refunded to you.
You may file this form if the filing status claimed on your 2025 Connecticut income tax return is married filing jointly and you meet all of the requirements under Am I a Nonobligated Spouse? on the back of this form.
You are a nonobligated spouse, if you meet all of the following requirements:
You filed a joint Connecticut income tax return reporting an overpayment of income tax, all or part of which was or is expected to be applied against past-due child support, a debt to any Connecticut state agency, or a tax debt owed to another state or the IRS by your spouse (the obligated spouse);
You received income (such as wages, interest, etc.) reported on the joint return; and you made Connecticut income tax payments (such as withholding, estimated tax payments, or payments with an extension) reported on the joint return or qualify for the Connecticut earned income tax credit or have a pass-through entity tax credit.
What to bring and attach to Form CT-8379
Attach copies of ALL Forms W-2, 1099 and Schedules CT K-1 to support income, withholding and any pass-through entity tax credit claimed on Form CT-8379.
A filled-in Form CT-8379 example: a nonobligated spouse claims her share of a refund
How to fill out Form CT-8379, box by box
Taxpayer Information as Shown on Joint Connecticut Income Tax Return
Taxpayer Information: Enter the taxpayer information exactly as it appears on your Connecticut income tax return. The name and Social Security Number (SSN) entered first on the joint tax return must also be entered first on Form CT-8379.
Nonobligated spouse: Yes or No.
Line a, Connecticut adjusted gross income
Connecticut adjusted gross income: Enter the joint amount as reported on your joint Connecticut income tax return (Form CT-1040, Line 5; Form CT-1040NR/PY, Line 5; or Form CT-1040X, Column C, Line 5). Then separately allocate the individual incomes according to which spouse earned the income. The sum of these must equal the amount reported as joint income.
Line b, Total tax
Total tax: Enter the joint Connecticut tax liability as reported on your joint Connecticut income tax return (Form CT-1040, Line 16; Form CT-1040NR/PY, Line 18; or Form CT-1040X, Column C, Line 20).
Line c, Connecticut income tax withheld
Connecticut income tax withheld: Enter the joint Connecticut withholding as reported on your joint Connecticut income tax return (Form CT-1040, Line 18; Form CT-1040NR/PY, Line 20; or Form CT-1040X, Column C, Line 21). List each spouse's share separately as shown on your individual withholding forms (such as W-2s or 1099s). Attach ALL Forms W-2/1099.
Payments and credits, lines d to g
Separate estimated Connecticut income tax payments or payments made with extension request: Enter any separately paid estimated Connecticut income tax payments or payments paid with request for extension, in the appropriate spaces.
Joint estimated Connecticut income tax payments or payments made with extension requests: Enter the total amount of any joint estimated Connecticut income tax payments or payments made with request for extension. Include overpayments applied from the previous year if filing jointly with the same spouse.
Connecticut earned income tax credit: Enter the amount reported on your joint Connecticut income tax return (Form CT-1040, Line 20a.; Form CT-1040X, Column C, Line 22a).
Pass-through entity tax credit: Enter the amount reported on your joint Connecticut income tax return (Form CT-1040, Line 20c.; Form CT-1040NR/PY, Line 22b.; Form CT-1040X, Column C, Line 22c). List each spouse's share of pass-through entity tax credit separately. Attach ALL Schedules CT K-1.
Line h, Joint amount overpaid
Joint amount overpaid: Enter the joint amount overpaid as reported on your joint Connecticut income tax return (Form CT-1040, Line 22; Form CT-1040NR/PY, Line 24; or Form CT-1040X, Column C, Line 27).
Nonobligated Spouse Refund: DRS will calculate the amount of the nonobligated spouse's refund. The nonobligated spouse's share of the joint Connecticut tax overpayment cannot exceed the joint overpayment.
Nonresidents and Part-Year Residents only
Nonresidents and Part-Year Residents only: Complete the Connecticut-Sourced Income chart. Enter the joint amount of your Connecticut-sourced income as reported on your Form CT-1040NR/PY, Line 6, or Form CT-1040X, Column C, Line 6. Separately allocate the Connecticut-sourced income between the two spouses. The sum of these must equal the amount reported as joint Connecticut-sourced income.
Sign Here, nonobligated spouse
Signature: The nonobligated spouse must sign this form.
Declaration: "I declare under penalty of law that I have examined this return (including any accompanying schedules and statements) and, to the best of my knowledge and belief, it is true, complete, and correct. I understand the penalty for willfully delivering a false return or document to DRS is a fine of not more than $5,000, imprisonment for not more than five years, or both" (checked November 7, 2026).
Others Who May Sign for the Nonobligated Spouse: Anyone with a signed LGL-001, Power of Attorney, may sign on behalf of the nonobligated spouse. Attach a copy of the LGL-001.
Paid preparer
Paid Preparer's Signature: Anyone you pay to prepare your return must sign and date it. Paid preparers must also enter their Personal Tax Identification Number (PTIN), and their firm's Federal Employer Identification Number (FEIN) in the spaces provided.
More rules for Form CT-8379
Keep a copy for your records.
Electronic filers and offset refunds
Paper filers
Paper filers: Check the box for Form CT-8379 on the front of your Connecticut income tax return.
You are filing electronically
Electronic filers: If you are filing electronically, select the indicator for Form CT-8379 on your Connecticut income tax return. Complete Form CT-8379 and upload as an attachment.
You previously filed your 2025 Connecticut income tax return and your refund was offset
If you previously filed your 2025 Connecticut income tax return and your refund was offset, do not file Form CT-1040X. Mail Form CT-8379 separately to: Department of Revenue Services PO Box 5035 Hartford CT 06102-5035
Before you go
Place this form on top of your completed Connecticut income tax return and check the box for Form CT-8379 on the front of your return. Complete in blue or black ink only. Please note that each form is year specific. To prevent any delay in processing your return, the correct year's form must be submitted to the Department of Revenue Services (DRS).
Common questions about Form CT-8379
Where do I file it?
File Form CT-8379 with Form CT-1040, Connecticut Resident Income Tax Return, Form CT-1040NR/PY, Connecticut Nonresident or Part-Year Resident Income Tax Return, or Form CT-1040X, Amended Income Tax Return for Individuals.
When is this form not the right one?
Do not use this form if you are requesting relief from a joint Connecticut income tax liability you believe should be paid only by your spouse (or former spouse). See Form CT-8857, Request for Innocent Spouse Relief (And Separation of Liability and Equitable Relief). Do not use this form to claim your share of a Connecticut income tax refund that was applied against your spouse's federal income tax liability. For information about IRS offsets, contact the IRS at the telephone number listed on the Notice of Refund Offset issued to you.
Sources
[1] Form CT-8379 (Rev. 12/25), Nonobligated Spouse Claim, Department of Revenue Services, State of Connecticut (the Official source link on this page).