Connecticut state income tax — guide for immigrants with ITIN

Connecticut state income tax — ITIN filer guide

Connecticut uses a graduated income tax from 2% to 6.99% (tax year 2026), administered by the Connecticut Department of Revenue Services. This guide covers who must file, how filing with an ITIN works, whether the state EITC applies to you, and when refunds arrive.

Connecticut refund timing

• E-filed returns: clean e-filed refunds issued within days (DRS has cited ~4 business days); allow longer if review is needed
• Paper returns: 10-12 weeks
• Check your Connecticut refund status

State tax agency

• Connecticut Department of Revenue Services — portal.ct.gov/drs
• Phone: 860-297-5962
• Free filing option: myconneCT — DRS's free state e-file for most residents

Facts verified 2026-06-11 against official state sources (primary source). Figures refresh with every dataset review.

Filing with an ITIN

Your ITIN is fully accepted on the Connecticut state return — states accept the IRS-issued taxpayer number, the same one you use federally. The flow is always the same:

1. Complete your federal return first (Form 1040 + ITIN)
2. Transfer your federal figures to Form CT-1040
3. Apply state-specific deductions and credits
4. E-file — myconneCT — DRS’s free state e-file for most residents
5. Or visit a VITA site for free in-person preparation

Connecticut Form CT-1040 vs. federal Form 1040 — what’s the difference?

The federal Form 1040 and Connecticut’s Form CT-1040 are two separate returns filed with two different agencies, and most ITIN filers who live in Connecticut have to file both:

• Form 1040 is your federal return — it goes to the IRS and is where your ITIN is used.
• Form CT-1040, the Connecticut Resident Income Tax Return, goes to the Connecticut Department of Revenue Services (DRS) — not the IRS — and computes your Connecticut state tax.

They are linked, not duplicated. The CT-1040 begins with the federal adjusted gross income (AGI) you already figured on your Form 1040 — you carry that number onto the state return, and Connecticut then applies its own additions and subtractions, its graduated 2%-6.99% rates, and its own credits (like the property tax credit below). That’s why you always complete the federal 1040 first: the state return reuses its bottom-line income figure.

If there’s one number to track between the two, it’s your federal AGI — get the federal 1040 right and the CT-1040 mostly follows from it.

How Connecticut’s seven brackets actually work

Connecticut’s 2026 rate schedule runs 2%, 4.5%, 5.5%, 6%, 6.5%, 6.9%, and 6.99% (per the DRS rate schedule — some summaries count six brackets, but the DRS table is authoritative). Two CT-specific mechanics catch filers by surprise:

• The benefit of the lower brackets phases out as income rises. Connecticut’s “tax benefit recapture” claws back the lower-bracket savings for higher earners, so a high earner effectively pays their top rate on ALL taxable income, not just the top slice. Most ITIN filers earning typical wages are unaffected; it matters above roughly six-figure incomes.
• The personal exemption also phases out, which creates short income ranges where each extra dollar is taxed at a noticeably higher effective rate than the bracket table suggests.

The practical takeaway: don’t estimate your CT tax by multiplying income by one bracket rate. Use the DRS tax tables in the CT-1040 instructions, or let software or a VITA preparer compute it.

If you moved into or out of Connecticut mid-year

Part-year residents file Form CT-1040NR/PY instead of the CT-1040, splitting income between Connecticut and the other state by residency period. Wages earned while living in Connecticut are CT-taxable even if the employer sits elsewhere. If you live in CT and commute to New York, both states will want a return — CT gives a credit for income tax properly paid to NY on the same wages, claimed on Schedule 2 of the CT-1040.

Connecticut state EITC — do ITIN filers qualify?

The federal EITC requires valid SSNs for you, your spouse, and qualifying children — ITIN filers can never claim it. What varies is the STATE credit:

As of the 2025 tax year, Connecticut has no general state child tax credit.

See how all 52 jurisdictions compare on the state tax hub and which tax credits ITIN filers can claim.

The Connecticut property tax credit — up to $300 (and ITIN filers can claim it)

Connecticut’s most ITIN-relevant state credit is the property tax credit of up to $300 against your Connecticut income tax — for property tax you paid during 2025 to a Connecticut political subdivision (your city or town) on a primary residence, a privately owned or leased motor vehicle, or both (tax year 2025, returns filed in 2026). You claim it on Schedule 3 of Form CT-1040, and the schedule must be attached to the return — if it isn’t, the credit is disallowed.

You get the full credit if your Connecticut AGI is at or below these limits: Single $49,500 · married filing jointly / qualifying surviving spouse $70,500 · married filing separately $35,250 · head of household $54,500. Above those amounts, the credit phases out per the Property Tax Credit Table in the CT-1040 instructions.

Why this matters for ITIN filers: the credit’s rules contain no SSN requirement — unlike the EITC, it attaches to tax you paid as a Connecticut resident, so ITIN filers who own a home or a registered car can claim it. And because Connecticut towns tax motor vehicles, even renters with a registered car can have qualifying property tax — you don’t need to own a home to claim this credit.

Related procedural information

• What is an ITIN? Apply for one
• Filing federal taxes with ITIN
• IRS notice codes — CP14, CP2000, and more
• ITIN-friendly banks comparison
• Free VITA tax help by state
• Tax software comparison
• State tax agency directory — all 52 jurisdictions

Last verified: 2026-06-15. Primary source: Connecticut Department of Revenue Services.

General procedural information for educational purposes. Not legal or tax advice. State tax rates change frequently — verify current figures with the state agency before filing. For case-specific guidance, consult a tax professional, enrolled agent, or CPA.