Form Your Connecticut LLC Without the Guesswork

If you run a business as a sole proprietor or a general partnership, there is no legal wall between you and the company. A dissatisfied customer, an unpaid vendor, or an accident on your premises becomes a claim against you personally: your savings, your car, potentially your house. Forming a limited liability company puts a legal entity between you and those risks.

Connecticut LLCs are governed by the Connecticut Uniform Limited Liability Company Act, codified in Chapter 613a of the General Statutes. Once your LLC is on file with the Secretary of the State, the company itself signs contracts, holds bank accounts, owes debts, and gets named in lawsuits. The members (the owners of an LLC) are generally shielded from the company's obligations, provided the business is run as a genuine separate entity.

What "limited liability" really covers

The shield is real, but it is not absolute. If you personally guarantee a loan or a lease, you are personally responsible for that specific obligation regardless of the LLC. And if you treat the company's money as your own (paying personal bills from the business account, skipping any real separation), a Connecticut court can set the shield aside under the doctrine commonly called piercing the veil. The protection holds when you keep a separate business bank account, keep clean books, and sign contracts in the company's name rather than your own.

For most self-employed residents, contractors, consultants, and small operators in Connecticut, the LLC lands in the right place. It gives you the liability separation that a sole proprietorship never can, without the board meetings, bylaws, and formality that a corporation demands.

Pass-through taxation by default

By default, the IRS taxes a single-member Connecticut LLC as a disregarded entity. You report the business's income and expenses on Schedule C of your personal federal return. A multi-member LLC is taxed as a partnership by default, with profits and losses flowing through to each member's personal return. In either case, the LLC itself usually pays no federal income tax at the entity level.

Connecticut does levy a state income tax on the individuals who receive that pass-through income, and the Department of Revenue Services administers a Pass-Through Entity Tax that has been elective since January 1, 2024. There is no entity-level Business Entity Tax anymore; it ended for tax periods beginning after 2018. If it fits your numbers, you can also elect S-corporation treatment with the IRS. These are conversations for your accountant: the right answer depends on your profit level and your goals.

Formation runs through the Connecticut Secretary of the State, Business Services Division, using the state's Business One Stop portal at business.ct.gov. The document that actually creates your LLC is the Certificate of Organization, filed online through a Business.CT.gov account or on the paper form by mail with a check payable to "Secretary of the State." The state fee is $120 either way, and by statute it includes the appointment of your registered agent. It is listed on the Secretary of the State's forms and fees page.

Processing timeline

Connecticut publishes no standard turnaround for formations. What the Secretary of the State does say is that "most filings made on Business.CT.gov are automatically accepted, so expedited service is unnecessary." If you still want it, expedite costs $50 per transaction and is offered only for online filings, at the end of the online process. Paper filings add mail time on top of review. If a lease, a bank account, or a contract depends on the LLC existing, file online.

What the Certificate of Organization includes

• LLC name: Must contain "limited liability company," "L.L.C.," or "LLC" and be distinguishable from every other business name already on file in Connecticut.
• Principal office address: A street address, not a P.O. box, plus a mailing address.
• Registered agent: The agent's name and addresses, with the agent's signature accepting the appointment.
• At least one member or manager: Name, title, business address, and residence address. Only three members or managers display on the public registry page.
• Business email and NAICS code: Both have been required since January 1, 2025, when Public Act 24-111 took effect.
• Organizer signature: Signed under penalty of false statement. The LLC itself cannot be its own organizer.

Forming the LLC happens once. Keeping it in good standing is an annual habit, and it is where owners most often slip.

Annual report

Every Connecticut LLC must file an annual report with the Secretary of the State, starting the year after it forms. The filing window opens January 1 and closes March 31, the fee is $80, and (this is a Connecticut quirk worth remembering) it can only be filed online through Business.CT.gov. The state emails a reminder about a month before it's due. The report confirms your name, addresses, at least one member or manager, your registered agent, email, and NAICS code. It is not a financial statement; you are not reporting revenue or profit.

Connecticut charges no late fee, but an overdue report blocks you from getting a Certificate of Legal Existence. Once an LLC is more than a year in default, the Secretary may email a notice that its rights and powers are forfeited, and if the report isn't filed within three months of that notice, the LLC is dissolved by forfeiture. Reinstatement then takes a $120 certificate of reinstatement, the members' consent, a current annual report, any penalties, and an agent appointment: more expensive and more disruptive than simply filing on time.

Registered agent maintenance

Your registered agent has to stay valid for the whole life of the LLC. If your agent moves, resigns, or stops being available, you file a Change of Agent (Form BUS-009) with the Secretary of the State, and the fee is $50. An LLC with a stale or invalid agent address is technically out of compliance even if the annual report is current.

Licenses, taxes, and the operating agreement

Connecticut has no single general business license, but many trades and professions require state licensure, and if you sell taxable goods or services you register for sales and use tax with the Department of Revenue Services. Separately, you should have an operating agreement in place. Connecticut does not require you to file one, but it governs how the company actually runs: ownership, profit splits, decision-making, and what happens when a member exits. Without one, the statutory defaults in Chapter 613a fill the gaps, and they may not match your intent.

Every Connecticut LLC must name a registered agent at formation and keep one in place afterward. The agent is the official contact point between your company and the state, and the person or business who accepts legal papers if your LLC is sued.

What the registered agent receives

• Service of process: lawsuits, summonses, and subpoenas
• Compliance notices, including annual report reminders and any administrative actions
• Official correspondence from the Secretary of the State

Under section 34-243n, the agent is either a person who resides in Connecticut or a Connecticut or authorized foreign business entity (a corporation, LLC, LLP, or statutory trust). An individual agent lists a Connecticut residence address that can't be a P.O. box, plus a Connecticut mailing address, and must sign the filing accepting the appointment. The LLC can never be its own agent.

Your options

You can act as your own registered agent, as a member or manager, if you live in Connecticut and are comfortable with that address appearing in the public business record, which is searchable online. You can name another trusted individual: a partner, an employee, or a Connecticut attorney. Or you can appoint a commercial registered agent service, which keeps a professional address on the public record instead of your home address and guarantees someone is present to receive documents even when you are traveling or the office is closed.

Mainstay Filing prepares and submits the formation paperwork so you are not left to decode the Business.CT.gov interface, second-guess the Certificate of Organization, or wonder whether you have satisfied every Connecticut requirement.

When you place an order, you give us what the state needs: your chosen LLC name, your address, your management preference, and your registered agent choice. We prepare the Certificate of Organization, file it with the Secretary of the State, apply for your EIN with the IRS (the number itself is free), and send you the completed documents once the state posts them. We include registered agent service, so your home address stays off the public record and there is always a professional address available to receive state mail and legal documents for you.

After formation, we track your annual report window and file the report for you each year, with the $80 state fee passed through at cost, so the March 31 deadline never sneaks up. The point is to get your entity active and keep it in good standing without turning you into an expert on Connecticut's filing procedures.

What we do not do

We are a filing service, not a law firm and not an accounting firm. We do not give legal or tax advice, and we do not draft the equity terms between partners. That is work for an attorney or a CPA. What we do is make sure the state-facing paperwork is correct and on time, so your attention stays on the business itself.