How to Start an LLC in Connecticut: A Step-by-Step Guide (2027)

How to Start an LLC in Connecticut (Quick Answer)

To start an LLC in Connecticut, file a Certificate of Organization with the Connecticut Secretary of the State through the Business One Stop portal, and pay the $120 state filing fee. Once the state approves it, your LLC legally exists, and from then on it files an $80 Annual Report between January 1 and March 31 each year.

First-year cost: $120 if you file the Certificate of Organization yourself. If you are not based in Connecticut, add a registered-agent service, commonly $35 to $300 a year, plus an optional $60 name reservation.

Connecticut sits directly between New York City and Boston, which makes it a genuine option for founders who want an East Coast US presence without paying New York's publication requirement, a cost that alone can run into the hundreds or thousands of dollars depending on the county. Hartford's insurance and financial-services industry adds another reason some fintech-adjacent founders look here first.

Forming an LLC in Connecticut follows the same core steps as any state, but a few details, the annual report window, the lack of a publication requirement, and an elective pass-through tax, are specific enough to cost you money if you miss them.

TL;DR

• Why Connecticut: NYC and Boston proximity, a Hartford insurance and financial-services hub, and a moderate cost profile with no publication requirement.
• Name: reservation is optional, $60 for 120 days, but your name is secured automatically once your Certificate of Organization is approved.
• Registered agent: required for the life of the LLC, physical Connecticut street address, no PO boxes.
• Certificate of Organization: $120 filed with the Connecticut Secretary of the State through the Business One Stop portal, online is faster than mail.
• EIN: free from the IRS, founders without an SSN or ITIN apply by phone, fax, or mail instead of the online tool.
• Form 5472: a 25%+ foreign-owned single-member LLC must file every year, even at zero revenue, or risk a $25,000 minimum penalty.
• Ongoing compliance: an $80 Annual Report is due January 1 through March 31 each year, plus a graduated 2% to 6.99% state income tax and an elective Pass-Through Entity Tax.

Why Form Your LLC in Connecticut?

Connecticut's location is the headline reason. It sits directly between the two largest East Coast metros, New York City and Boston, so a Connecticut LLC can serve both markets without the higher formation and ongoing costs New York carries.

Hartford is also a major US insurance industry center. That matters if your business is fintech or insurtech adjacent, or if you're looking for banking relationships or partners already embedded in that industry, since local banks and service providers are used to working with insurance-adjacent companies.

On cost, Connecticut lands in the moderate range. It's cheaper than New York once you account for New York's publication requirement, and it has no publication requirement of its own to budget for. Between the $120 formation fee and the $80 annual report, the ongoing cost of keeping a Connecticut LLC in good standing is predictable from year one.

None of this makes Connecticut the automatic answer for every founder. If your customers and operations are entirely in another state, forming there directly can be simpler than forming in Connecticut and later registering as a foreign LLC elsewhere. Connecticut fits best when the business genuinely touches the Northeast corridor.

Step 1: Choose and Reserve Your LLC Name

Your LLC's name needs to be distinguishable from other registered Connecticut entities and typically must include a designator like "LLC" or "Limited Liability Company."

• Search first. The Connecticut Secretary of the State's business database lets you check name availability before you file anything.
• Reservation is optional, not required. You can reserve a name for $60, and the reservation holds it for 120 days.
• Reservation is a convenience, not a requirement. Filing the Certificate of Organization locks in your name at the same moment it creates the LLC, at no added cost. The $60 hold only earns its keep if you need weeks or months to get your paperwork together before you're ready to file.

Step 2: Appoint a Registered Agent

Every Connecticut LLC needs a registered agent for the life of the entity: a person or business with a physical Connecticut street address, available during business hours to receive legal notices on the LLC's behalf. A PO box doesn't qualify.

• An individual agent must be a Connecticut resident, at least 18, with a real street address in the state.
• A business entity agent must be authorized to transact business in Connecticut.
• Founders forming from outside Connecticut, or outside the US, typically use a commercial registered agent service instead of naming themselves.

Step 3: File Your Certificate of Organization

This is the filing that legally creates your LLC. You file it with the Connecticut Secretary of the State's Business Services Division, through the state's "Business One Stop" online portal.

• Filing fee: $120, whether you file online or by mail.
• Processing time: online filing typically takes 2 to 3 business days; mail filing runs roughly 7 to 10 business days plus mail transit time.
• Expedited option: an additional $50 gets faster processing than the standard queue, though the exact turnaround for that tier isn't clearly documented anywhere official.
• What it lists: the LLC's name, registered agent, and principal address.

Step 4: Draft an Operating Agreement

An operating agreement is an internal document that spells out how the LLC is owned and run: each member's ownership share, whether the LLC is member-managed or manager-managed, how profits and losses are split, and what happens if a member wants to leave or the LLC needs to dissolve.

• Connecticut doesn't require you to file it with the state. It stays in your own records rather than going to the Secretary of the State.
• It backs up your liability protection. A written operating agreement helps show the LLC is genuinely run as a separate entity from its owner, something banks and the IRS both look at if the LLC's structure is ever challenged.
• It matters even for single-member LLCs. Without one, state default rules fill the gap, and those defaults may not match how you actually intend to run the business.

Step 5: Get an EIN, Even Without an SSN

An Employer Identification Number (EIN) is what the IRS uses to identify your LLC for tax purposes, and it's free directly from the IRS. Most founders apply online and get one in minutes.

Founders without a Social Security Number or an Individual Taxpayer Identification Number (ITIN) can't use the online tool. They apply instead using Form SS-4 by phone, fax, or mail.

The manual route's wait depends mostly on volume and how completely the form was filled out. Getting the responsible-party details right the first time matters more here, since a rejected submission means starting the wait over.

Open a US Business Bank Account

Once your Certificate of Organization is approved and your EIN has arrived, open a dedicated business bank account before the LLC takes in or pays out a single dollar.

• Bring the paperwork. Banks typically want the approved Certificate of Organization, your EIN confirmation letter, and an operating agreement, even the internal one Connecticut never asked you to file with the state.
• Keep funds separate from day one. Running business money through a personal account is one of the fastest ways to undercut the liability protection the LLC exists to provide, and it makes bookkeeping at tax time far messier than it needs to be.
• Non-US founders should expect extra verification. Some banks ask for additional identity documents or an in-person visit before opening an account without a US-based owner present, so confirm a specific bank's requirements before you count on a fully remote setup.

The Secretary of the State has no role in this step, which is exactly why it's the one founders tend to leave half-finished after an otherwise complete filing.

Step 6: File Form 5472 if the LLC Is Foreign-Owned

Foreign ownership brings a federal obligation that has nothing to do with Connecticut's own paperwork, and it's the one most LLC checklists leave out entirely. If a single foreign person or entity owns 25% or more of your single-member LLC, the IRS expects a Form 5472 every year, whether the business brought in a dollar or sat completely idle.

• It rides along with a pro forma Form 1120, a bare-bones corporate return that accompanies the 5472 as a filing formality, not because the LLC actually owes corporate tax.
• It documents money moving between the LLC and its foreign owner, capital put in, payments made for services, and similar reportable transactions.
• It shares your federal return's deadline, and you can typically push it back with the same extension request.
• Inactivity is not an exemption. An LLC that never generated revenue is still on the hook for this filing.

Note: the IRS sets the minimum penalty for a late or missing Form 5472 at $25,000, assessed per form, per year, income or no income.

Step 7: Handle Connecticut's Ongoing Compliance

Forming the LLC isn't the end of the paperwork. Connecticut layers a few recurring obligations on top of the federal ones above.

The Annual Report Window Is Easy to Miss

Connecticut LLCs file an Annual Report each year for an $80 fee. It's due within a specific window: January 1 through March 31, with the first report due the year after formation.

• Miss the window and a penalty applies. Sources describe the late fee differently, so treat the exact figure as unconfirmed rather than relying on one number.
• Continued non-filing risks more than a fee. It can put the LLC at risk of administrative dissolution and loss of good standing with the state.

Connecticut's Income Tax and the PTET Election

Connecticut applies a graduated personal income tax across seven brackets, ranging from 2% to 6.99%, current since a 2023 rate cut that took effect for tax year 2024 onward.

• Personal exemption: up to $15,000 for single filers or $24,000 for joint filers, phasing out above $30,000 and $48,000 in Connecticut AGI.
• The Pass-Through Entity Tax (PTET) is elective, a 6.99% tax on Connecticut-source income that "affected business entities" can elect into annually, largely as a workaround to the federal SALT deduction cap.
• Owners get a nonrefundable credit for the tax paid at the entity level, with a 5-year carryforward for any unused credit.

For most founders, the PTET election is worth a conversation with a tax professional each year rather than a set-and-forget choice. Whether it saves money depends on the owner's overall tax picture, and Connecticut's own guidance treats it as elective for a reason.

Connecticut LLC Costs Breakdown

Connecticut's cost profile is predictable from year one: a $120 filing fee, an $80 report every year, and no publication bill of the kind New York founders budget for. One figure is missing on purpose, the Annual Report late fee, because sources describe it differently and the exact number isn't confirmed.

How Long Does It Take to Form an LLC in Connecticut?

Connecticut gives real numbers for both filing routes. Online through the Business One Stop portal, the Certificate of Organization typically takes 2 to 3 business days. By mail it runs roughly 7 to 10 business days, plus mail transit time on top.

An additional $50 buys faster processing than the standard queue, though the exact turnaround for that tier isn't clearly documented anywhere official. For most founders the online route is quick enough that the expedite fee is hard to justify.

Formation is only the first leg. Your EIN comes in minutes online if you have an SSN or ITIN, or same day to several weeks by Form SS-4 without one, and the bank account can only follow the EIN.

The first $80 Annual Report isn't due until the year after formation, inside the January 1 to March 31 window.

Common Mistakes to Avoid

• Missing the January 1 to March 31 Annual Report window: the deadline isn't tied to your formation date, it's a fixed calendar window every year.
• Not knowing the PTET election exists: it can be a real planning tool for owners facing the federal SALT cap, but only if someone evaluates the election each year.
• Treating the EIN as the finish line: for a foreign-owned LLC, it's closer to the start of an annual filing obligation than the end of the process.
• Assuming zero revenue means zero filing obligation: Form 5472 attaches to foreign ownership, not to how much the LLC earned.
• Using a home or friend's address as the registered agent: it can put the LLC out of good standing and exposes a personal address on public record.

How FinStackk Helps

FinStackk is an accounting and tax compliance platform for U.S. businesses, helping you go from incorporation to ongoing accounting, tax, and compliance, all in one place.

Filing the Certificate of Organization with Connecticut's Business One Stop portal, getting an EIN, and lining up a registered agent are exactly the steps Fin-Start handles for you.

Once your LLC exists, Fin-Tax keeps ongoing filings, including Form 5472 and Connecticut's Annual Report, on a proactive deadline calendar instead of leaving you to track it yourself. Book a free demo to see both in action.

FAQ

How does forming an LLC in Connecticut compare to New York on cost?

Connecticut's Certificate of Organization costs $120 plus an $80 Annual Report each year, and Connecticut has no publication requirement. New York's publication requirement alone can run from roughly $200 to over $1,900 depending on the county, on top of its own formation and annual fees. For founders comparing the two states purely on cost and paperwork, Connecticut is generally the lighter lift.

Do I need to reserve my LLC name before filing in Connecticut?

No. Name reservation is optional and only useful if you want to hold a name before you're ready to file. It costs $60 and lasts 120 days. Once your Certificate of Organization is approved, your chosen name is secured automatically at no extra cost.

What happens if my LLC formed outside Connecticut wants to do business there?

An LLC formed in another state that does business in Connecticut generally needs to register as a foreign LLC with the Connecticut Secretary of the State, a separate filing from domestic formation. The current fee for that filing wasn't independently confirmed here, so check the Connecticut Secretary of the State's site directly before you file.

Does a Connecticut LLC need an operating agreement?

Connecticut doesn't require you to file an operating agreement with the state. It stays in your own records rather than going to the Secretary of the State, but you still want one in place.

It spells out each member's ownership share, whether the LLC is member-managed or manager-managed, how profits and losses are split, and what happens if a member wants to leave. Without one, state default rules fill the gap, and those defaults may not match how you intend to run the business.

Banks and the IRS both look for evidence that the LLC runs as its own entity, and the agreement is the clearest document you have to show it.

Can a non-US resident start an LLC in Connecticut?

Yes. Connecticut sets no residency or citizenship requirement to own a Connecticut LLC. You'll still need a registered agent with a physical Connecticut street address, which usually means a paid service if you're not in the state. Because you won't have an SSN, you apply for your EIN on Form SS-4 by phone, fax, or mail instead of the online tool. If your LLC is single-member and 25% or more foreign-owned, you also file Form 5472 with the IRS every year, even at zero revenue, or risk a $25,000 minimum penalty.

What are the annual filing requirements for a single-member LLC in Connecticut?

Every Connecticut LLC, including a single-member one, files an $80 Annual Report with the Connecticut Secretary of the State each year, due within the January 1 through March 31 window. The first report is due the year after formation, and the deadline is a fixed calendar window rather than tied to your formation date. A single-member LLC that is 25% or more foreign-owned has an added federal obligation: Form 5472, filed yearly with the IRS.

Does a Connecticut LLC pay income tax?

Connecticut applies a graduated personal income tax across seven brackets, ranging from 2% to 6.99%, which flows through to a pass-through LLC's income at the owner level. The state also offers an elective Pass-Through Entity Tax (PTET) at 6.99% on Connecticut-source income, largely as a workaround to the federal SALT deduction cap, with owners receiving a credit for the tax paid at the entity level. Whether the PTET election saves money depends on your overall tax picture, so it's worth a conversation with a tax professional each year.