Forming an LLC in Connecticut costs $120 to file the Certificate of Organization with the Connecticut Secretary of the State, with online approval through CT business.gov in 2–3 business days. The catch that surprises most new owners: Connecticut is the only U.S. state with a mandatory pass-through entity tax (PTET) on LLCs and partnerships — 6.99% on Connecticut-source LLC profits. While LLC members get a partial offsetting credit on their personal returns, the cash-flow impact is real. The annual report is $80 (due January 1 to March 31), placing Connecticut among the more expensive states ongoing. Connecticut's strengths are insurance (Hartford), bioscience and pharma (Yale-area cluster), and defense manufacturing (Sikorsky, Pratt & Whitney). For founders in those industries, the state's deep talent and capital usually justify the cost; for everyone else, the mandatory PTET makes neighboring states more attractive.
How much does a Connecticut LLC cost?
Budget at least $269 to launch a Connecticut LLC in Year 1 — that covers the $120 state filing fee plus a $149 registered agent service if you choose to use one. The Certificate of Organization goes to the Connecticut Secretary of State and typically clears in 3–5 business days, with no expedite option required for most founders. After formation, Connecticut keeps ongoing costs predictable: a flat $80 annual report is the only recurring state obligation, with no minimum franchise tax or publication requirement (unlike New York, which can add $1,000+ in publication fees, or California's $800 annual minimum). Over five years, expect to spend roughly $589 total — $269 in Year 1 followed by $80 per year. Connecticut's straightforward fee structure makes it one of the more cost-transparent states on the East Coast.
Why form your LLC in Connecticut
Strong insurance, finance, and bioscience clusters. The mandatory PTET makes Connecticut more complex than its neighbors — most solo founders consider whether registering elsewhere makes sense.
- Strong insurance industry cluster centered in Hartford
- Bioscience, pharma, and medical-device cluster (New Haven/Yale)
- Defense and aerospace manufacturing base
- High-income consumer market — Fairfield County is one of the wealthiest in the U.S.
- 2–3 business day online approval
- Strong professional services ecosystem
Best fit for: Insurance (Hartford) · Bioscience · Defense manufacturing
Don’t want to file yourself? Northwest Registered Agent files your Connecticut LLC for $39 + state fee and acts as your registered agent the first year free.
How to form a Connecticut LLC in 7 steps
- 1Search the Connecticut business name database
Use the Connecticut Secretary of the State CONCORD business search to confirm your name is available. The name must include "Limited Liability Company", "L.L.C.", or "LLC". You can reserve a name for $60 (held 120 days) if needed.
- 2Appoint a Connecticut registered agent
Required to have a physical Connecticut street address (no PO boxes). Can be the LLC owner if they're a CT resident, or a commercial registered agent service. The agent receives service of process and state notices.
- 3File the Certificate of Organization
File online through CT business.gov for $120. Standard processing is 2–3 business days. The Certificate includes LLC name, principal office address, mailing address, registered agent, NAICS code, member/manager structure, and email contact.
- 4Draft an Operating Agreement
Not required by Connecticut law but strongly recommended. Defines ownership percentages, profit/loss splits, management authority, and dissolution procedures. Banks routinely ask for it.
- 5Apply for an EIN with the IRS
Free at irs.gov, takes 10 minutes online. Required to open a business bank account, register with the Connecticut Department of Revenue Services (DRS), and file federal taxes.
- 6Register with the Connecticut DRS
Register through myconneCT for sales and use tax (if you sell taxable goods/services), withholding tax (if you have employees), and the mandatory PTET. The PTET registration is critical — it applies even to single-member LLCs treated as partnerships for federal tax purposes.
- 7Calendar the annual report and PTET filings
The Connecticut LLC annual report is due each year between January 1 and March 31, with an $80 fee. The PTET return (Form CT-1065/CT-1120SI) is due by the 15th day of the 3rd month after the close of the LLC's tax year (March 15 for calendar-year LLCs).
File directly with Connecticut Secretary of the State →
Connecticut LLC taxes & compliance
Connecticut is the only state with a mandatory pass-through entity tax. Multi-member LLCs in particular need to plan for the 6.99% PTET, even though members get a partial credit on their personal returns.
Ongoing compliance checklist
- Annual report — $80, due January 1 to March 31
- Mandatory PTET return (Form CT-1065/CT-1120SI) — due 15th day of 3rd month after fiscal year end
- Sales and use tax filings (DRS) — monthly or quarterly based on volume
- Withholding tax filings if you have CT employees
- Federal income tax (Form 1065 multi-member, Schedule C SMLLC)
Registered agent rules
Required — CT physical address.
Hidden costs new Connecticut LLC owners forget
- Mandatory Pass-Through Entity Tax (PTET): 6.99% on CT-source LLC profits
- Annual report fee: $80, due January 1 to March 31 each year
- Top personal income tax rate of 6.99%
- Combined sales tax: 6.35% state (no local add-ons, but luxury rate of 7.75%)
- Foreign LLC qualification: $120
- Property taxes among the highest in the U.S.
Should you use a formation service in Connecticut?
You can absolutely file directly with the Connecticut Secretary of the State for the $120 state fee. The reasons most Connecticut owners use a service anyway are (1) registered-agent privacy — keeping their home address off public filings — and (2) calendar reminders for ongoing compliance.
Have Northwest form your Connecticut LLC for $39 + state fee
Free registered agent for the first year. Real human support. Privacy-by-default — your home address stays off public filings.
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See the real 5-year cost of a Connecticut LLC
Filing fee · registered agent · annual report · franchise tax — all calculated, year by year.
Open cost calculator for Connecticut →Connecticut's pass-through entity tax: the SALT workaround LLC owners actually use
Connecticut was among the first states to enact a Pass-Through Entity Tax (PTET), and for multi-member LLCs it changes the tax math significantly. Since the 2017 federal tax law capped the state and local tax (SALT) deduction at $10,000, Connecticut LLC members in higher income brackets were losing thousands in federal deductions. The PTET election lets the LLC itself pay Connecticut income tax at 6.99% on behalf of members, then claim that payment as a full federal business deduction — bypassing the SALT cap entirely. Members receive a Connecticut credit to avoid double taxation. This is not automatic: the LLC must affirmatively elect it each year before the return deadline. Separately, Connecticut repealed its $250 biennial Business Entity Tax in 2018, so ignore any outdated source that still lists it. The annual report fee is a flat $80 due March 31 — no graduated fee based on capital like some neighboring states. Connecticut also has no newspaper publication requirement, making it far cheaper than New York for businesses operating near the state line who might consider either jurisdiction.
Year 1: $120 (state filing fee) + $149 (registered agent) + $80 (first annual report, due March 31 of the following year) = $349 total first-year cost. By Year 5: add four more annual report cycles at $80 each and four additional registered agent years at $149 each — approximately $1,513 cumulative over five years, before any optional PTET election or professional fees.
Many Connecticut LLC owners miss the March 31 annual report deadline because they assume it follows their LLC's formation anniversary, as it does in many other states. Connecticut uses a fixed calendar deadline — March 31 every year — regardless of when you formed your LLC. Missing it triggers a $50 late fee and can eventually lead to administrative dissolution, voiding liability protection retroactively.
Connecticut LLC: frequently asked questions
How much does it cost to form an LLC in Connecticut?
The Connecticut Secretary of the State charges $120 to file the Certificate of Organization. The annual report is $80, due between January 1 and March 31 each year. Realistic year-one cost: $120. Ongoing yearly cost: $80 plus the mandatory 6.99% PTET on LLC profits — that PTET is what makes Connecticut more expensive than its surface-level fees suggest.
How long does it take to form an LLC in Connecticut?
Online filings through CT business.gov approve in 2–3 business days. There is no formal expedited tier. Mail filings can take 7–10 business days.
What is the Connecticut LLC PTET (Pass-Through Entity Tax)?
Connecticut is the only U.S. state with a mandatory pass-through entity tax. LLCs taxed as partnerships (and S-corps) owe 6.99% on Connecticut-source income at the entity level. LLC members receive a partial offsetting credit on their personal Connecticut income tax returns, but the entity itself pays the tax up front. This applies to virtually every Connecticut LLC except single-member LLCs that are disregarded entities for federal tax (those pay through the owner's personal return only).
Does Connecticut have an LLC annual report?
Yes. The Connecticut LLC annual report is due each year between January 1 and March 31, with an $80 filing fee. File online through CT business.gov. Late filings result in administrative dissolution if not cured.
Can a single-member LLC avoid the Connecticut PTET?
A single-member LLC that's a "disregarded entity" for federal tax (the default for most SMLLCs) is not subject to the PTET because it's not treated as a partnership or S-corp. The owner reports income on their personal CT return. SMLLCs that elect S-corp taxation, however, are subject to the PTET.
Can a non-resident form an LLC in Connecticut?
Yes. Connecticut has no residency requirement for LLC members or managers. You only need a Connecticut-based registered agent. Out-of-state owners commonly use a commercial registered agent service.
Is Connecticut a good state to form an LLC?
For Connecticut residents and businesses tied to the insurance, biotech, defense, or finance clusters: yes. For everyone else, the mandatory 6.99% PTET makes Connecticut materially more expensive than neighboring Massachusetts, New York, or Rhode Island. Solo founders without a CT footprint should usually form in their home state.
What is the Connecticut LLC tax classification?
By default, single-member LLCs are disregarded entities and multi-member LLCs are partnerships for federal tax. You can elect S-corp or C-corp treatment by filing IRS Form 2553 or 8832. Connecticut generally follows the federal classification — but the mandatory PTET applies whenever the LLC is taxed as a partnership or S-corp.