Start a Connecticut LLP — Step-by-Step Registration Guide

Before anything touches the state portal, make sure an LLP is actually what you want. A partnership of any kind requires at least two partners, so a solo founder cannot register an LLP — an LLC is the right tool there. An LLP is built for two or more people going into business together who want the flexibility of a partnership plus protection from one another's mistakes.

The typical LLP candidate

Licensed professionals form the most common LLPs — law, accounting, architecture, engineering, medicine, and design firms — because they carry malpractice exposure and want each partner walled off from the others' errors. But you don't need a professional license to register one. Any multi-partner venture that values partnership economics and cross-liability protection can use the form.

Confirm licensing rules first

If you and your partners hold professional licenses, check with your Connecticut licensing board before registering. Some professions have entity rules or naming conventions that affect how you register and what your firm can be called. It's far easier to confirm this upfront than to unwind a filing later.

Your LLP's name must be distinguishable from every other business name already on file with the Connecticut Secretary of the State. "Distinguishable" is a legal standard — a name that differs only by punctuation, spacing, or a filler word like "the" or "and" may not clear.

Start at the Connecticut business records search. Search your proposed name and close variations. If a conflicting name turns up, the state may reject your registration, which wastes time. Have a backup name ready.

Name requirements for an LLP

• The name must include a limited liability partnership designation such as "LLP," "L.L.P.," or "Registered Limited Liability Partnership."
• It must be distinguishable from other names already registered in Connecticut.
• Certain restricted words — those implying banking, insurance, or a government connection — may require additional approval or be off-limits.
• Licensed professionals may face additional naming conventions from their licensing board.

Optional name reservation

If you're not ready to file but want to hold your chosen name, Connecticut lets you reserve a business name for a limited period through the Secretary of the State. Reserving a name does not register the LLP — it simply holds the name while you finish the other steps.

Before you file, you need a registered agent decided on and willing to serve, because the agent's name and Connecticut address go into the registration. Connecticut requires every registered LLP to keep a registered agent with a physical in-state street address for the entire life of the partnership.

Who can serve

• A partner or another individual: Any Connecticut resident with a physical street address who is reliably available during business hours. Their address becomes part of the public record.
• A commercial registered agent service: A firm that Connecticut authorizes to fill the registered agent role. It keeps its professional address on the public record instead of a partner's home address and ensures someone is always available to accept documents.

Why the choice matters

If you name a partner's home as the agent address, that address becomes searchable in the public business database. Many partnerships use a commercial service specifically to keep home addresses private and to guarantee coverage when partners are in court, traveling, or out of the office — exactly the times a lawsuit or state notice tends to arrive.

The registration is the filing that creates your limited liability partnership in Connecticut's official records. You file online through the CT Business One Stop at business.ct.gov, operated by the Secretary of the State's Business Services Division. The state charges a filing fee for the registration — the receipt card on this page shows the current amount.

Online submissions are typically processed within a couple of business days; paper filings take considerably longer. Once processed, the LLP appears in the state's public business search and your filed documents become available.

What the registration includes

• Partnership name: Your full legal name with the required LLP designation.
• Principal office address: The main business address. A street address is expected, not a bare P.O. box.
• Registered agent name and Connecticut street address: The agent's actual physical address, and the agent's agreement to serve.
• LLP election: The statement that the partnership is registering as a limited liability partnership under Connecticut law.

Double-check every field before submitting. A typo in the partnership name or agent address means an amendment later, which costs time you'd rather spend on the business.

An Employer Identification Number is the partnership's federal tax ID. A multi-partner LLP needs one — the IRS treats an LLP as a partnership for tax purposes by default, and a partnership files its own federal information return and issues Schedule K-1s to the partners.

You apply directly with the IRS, and there is no IRS charge for an EIN. The fastest route is the online EIN application, which issues the number immediately once you complete it. You'll need the partnership's legal name, address, and a responsible party's taxpayer ID.

You'll use the EIN to open a business bank account, file partnership tax returns, run payroll if you hire employees, and register for any state tax accounts your business needs.

Connecticut does not require you to file a partnership agreement with the state, but for a multi-partner LLP it is close to essential. The agreement is the internal rulebook that governs how the partnership actually operates.

What a strong partnership agreement covers

• Capital contributions: What each partner puts in — cash, property, or services — and how that's tracked.
• Profit and loss allocation: How the partnership splits money, which does not have to be equal.
• Management and voting: Who decides what, and which decisions require unanimous consent.
• Admitting and removing partners: The process for bringing in a new partner or handling one who leaves.
• Dissolution and buyouts: What happens to a departing partner's interest and how the partnership winds down if it ends.

Without a written agreement, the default provisions of the Connecticut Uniform Partnership Act govern these questions, and the defaults rarely match what partners actually want. This is a document worth having an attorney help draft — Mainstay Filing handles the state registration, not the substantive terms of your agreement.

With your registration filed and your EIN in hand, open a dedicated business bank account for the LLP. Keeping partnership money separate from personal money is not optional bookkeeping hygiene — it's part of what preserves the liability shield. Commingling funds is one of the fastest ways to undermine the protection you registered to get.

Ongoing compliance

• Annual report: Connecticut LLPs file an annual report with the Secretary of the State through the Business One Stop portal to keep the state's record current. Miss it and the entity can fall out of good standing.
• Registered agent: Keep a valid Connecticut agent on file at all times; update the record promptly if the agent changes.
• Taxes and licenses: File the partnership's federal return and issue K-1s to partners, register for any Connecticut tax accounts you need, and maintain any professional or local licenses your business requires.

Handle these steps in order and you'll go from an idea to a fully registered, compliant Connecticut LLP. Mainstay Filing can take the registration and registered agent pieces off your plate and remind you when the annual report comes due.