Connecticut State Income Tax for LLCs — Rates & Filing
Connecticut's income tax ranges from 3% to 6.99% for individuals (Connecticut law), applying to LLC members' pass-through income. Connecticut also imposes a 3% income tax surcharge on high earners (Connecticut law), effectively raising the top rate. The state's pass-through entity tax (PET) option under Connecticut law makes Connecticut unique — it pioneered the SALT cap workaround in 2018. File and pay through myconneCT (portal.ct.gov/drs). For the full tax picture, see our tax guide. For formation, see our LLC guide.
Connecticut Income Tax Rates (2025)
| Taxable Income (Single) | Rate |
|---|---|
| $0 - $10,000 | 3.0% |
| $10,000 - $50,000 | 5.0% |
| $50,000 - $100,000 | 5.5% |
| $100,000 - $200,000 | 6.0% |
| $200,000 - $250,000 | 6.5% |
| Over $250,000 | 6.99% |
Plus: 3% surcharge on CT AGI over $200,000 (single) / $400,000 (joint) — capped so that total tax doesn't exceed 6.99% of entire CT AGI plus the surcharge on the excess.
How LLC Income Is Taxed
- Single-member LLC: Schedule C income flows to CT Form CT-1040
- Multi-member LLC: Each member's K-1 share reported on their CT-1040
- Non-resident members: Owe CT tax on CT-sourced income, file CT-1040NR/PY
Pass-Through Entity Tax (PET) — The Connecticut Advantage
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Get StartedConnecticut pioneered this in 2018, and it's now considered essential for qualifying LLCs:
- LLC elects to pay CT income tax at entity level (6.99% flat)
- Members receive dollar-for-dollar credit against their personal CT tax
- Entity-level payment is fully deductible on the federal return
- Bypasses the $10,000 SALT deduction cap entirely
- Must file CT Form CT-1065/CT-1120SI by March 15
Example — member with $300K Connecticut income:
| Without PET | With PET | |
|---|---|---|
| CT tax owed | ~$19,000 | ~$21,000 (entity pays at 6.99%) |
| SALT deduction (federal) | Capped at $10,000 | Full ~$21,000 (business expense) |
| Federal tax savings | $2,200 (at 22% on $10K) | $4,620 (at 22% on $21K) |
| Net benefit of PET | — | ~$2,400 (more at higher brackets) |
At higher incomes and the 37% federal bracket, savings are significantly larger.
Filing Requirements
All filed through myconneCT (portal.ct.gov/drs) — Connecticut Department of Revenue Services' online filing system:
| Filing | Due Date | Form | Portal |
|---|---|---|---|
| CT personal income tax | April 15 | CT-1040 | myconneCT |
| PET return (entity level) | March 15 | CT-1065/CT-1120SI | myconneCT |
| Estimated payments (personal) | Quarterly (Apr 15/Jun 15/Sep 15/Jan 15) | CT-1040ES | myconneCT |
| PET estimated payments | Per DRS schedule (quarterly) | CT-1065/CT-1120SI ES | myconneCT |
Connecticut quirk: The PET estimated payments are due quarterly and must equal 90% of the current year's expected liability OR 100% of the prior year's liability to avoid underpayment penalties under Connecticut law.
FAQ
Is the PET mandatory?
No — it's an election. But for multi-member LLCs with higher-income members, it's almost always beneficial. Single-member LLCs are also eligible for the PET (Connecticut expanded eligibility).
Does Connecticut tax retirement income from my LLC?
If you receive retirement distributions from a qualified plan funded by LLC income, Connecticut provides partial exemptions for Social Security and certain pension income. Active LLC business income is fully taxed.
How does CT compare to neighboring states?
New York: 4%-10.9% (higher top rate). Massachusetts: 5% flat (lower for some). Rhode Island: 3.75%-5.99%. Connecticut's 6.99% top rate is moderate for the Northeast, and the PET option effectively reduces the federal cost of paying it.