CT business registration starts at the Secretary of the State’s office, where you file a Certificate of Organization for an LLC ($120) or a Certificate of Incorporation for a stock corporation ($250). That filing is one step in a sequence that also includes a federal Employer Identification Number, registration with the Department of Revenue Services, any local permits your location requires, and an annual report that keeps the entity in good standing. Skip a step and you can lose liability protection, face penalties, or have the state dissolve the business.
Choose a Business Structure First
Your entity type decides how much personal liability you carry, how the business is taxed, and how much recurring paperwork you deal with.
An LLC separates your personal assets from the business’s debts and lawsuits. If the LLC is sued or can’t pay a creditor, your house and savings generally aren’t at risk. LLCs also offer flexibility in how they’re taxed and managed, which is why they’re the common choice for small businesses.
Corporations provide the same liability shield with more formality: a board of directors, corporate officers, bylaws, and meeting minutes. A C-Corporation is taxed separately from its owners; an S-Corporation passes income through to shareholders’ personal returns. Corporations are the standard structure when you plan to raise capital by selling shares.
Sole proprietorships and general partnerships don’t require any formation filing with the state. The tradeoff is real: your personal assets are fully exposed to business debts and lawsuits. For most people, the $120 cost of forming an LLC is worth the protection.
Check Name Availability and Register a Trade Name if You Need One
Before you file anything, search the state’s Business Records Search to confirm your desired name isn’t already taken. Connecticut won’t approve a formation filing if the name is too similar to an existing entity.
If you plan to operate under a name different from your legal entity name, or you’re a sole proprietor or partnership that didn’t file formation documents, register a trade name (a “doing business as” or DBA). Trade names are filed with the town clerk where the business primarily operates, not with the Secretary of the State, and cost $20.1Business.CT.gov. Trade Names The application must be signed and notarized.
State or town name registration is not a trademark. To prevent other businesses from using your name nationwide, you need a separate federal trademark through the U.S. Patent and Trademark Office. Registering with Connecticut only stops another Connecticut entity from filing the same name.
Prepare and File Your Formation Documents
Every formal entity needs a registered agent, meaning a person or business authorized to accept legal papers and official correspondence for you. The agent must be a Connecticut resident age 18 or older, or another business entity already registered with the Secretary of the State that has a Connecticut address.2Business.CT.gov. Who Can Be an Agent You can be your own agent if you’re a Connecticut resident. The agent’s address must be a street and number; P.O. boxes don’t satisfy the requirement.3Justia Law. Connecticut Code Title 34 – Section 34-243n Registered Agent The business also needs a principal office address (not a P.O. box) and a mailing address, which can be a P.O. box.
For an LLC, complete the Certificate of Organization. It requires the name and address of at least one member or manager, the registered agent’s name, and the agent’s signed acceptance.4Secretary of the State of Connecticut. Certificate of Organization – Limited Liability Company For a corporation, complete the Certificate of Incorporation, which also requires the total number of authorized shares. Share count matters because it affects franchise tax at filing.
Submit your documents to the Commercial Recording Division with the filing fee. An LLC’s Certificate of Organization costs $120.5Business.CT.gov. Domestic Limited Liability Companies Forms and Fees A stock corporation’s Certificate of Incorporation costs $250, which includes the minimum franchise tax for authorizing up to 20,000 shares.6State of Connecticut Business Services Division. Fee Schedule Authorizing more than 20,000 shares adds franchise tax on a sliding scale.
Filing online through the state’s business portal is the fastest option. Expedited processing is available for an additional $50 per transaction.7Business.CT.gov. Expedited Services You can also submit paper forms by mail or in person. Once accepted, the state returns a stamped copy confirming legal existence. Your filing date sets the clock for later compliance deadlines.
Registering an Out-of-State Business
If your business was formed in another state but you want to operate in Connecticut, you must register as a foreign entity. A foreign LLC files a Foreign Registration Statement for $120 and files annual reports on the same schedule and at the same cost as domestic LLCs.8Business.CT.gov. Foreign LLC Forms and Fees Foreign corporations follow a similar process with their own fees. Operating in Connecticut without registering exposes you to penalties and can prevent you from enforcing contracts in state courts.
Get a Federal Employer Identification Number
Once state formation is approved, apply for an EIN from the IRS. An EIN functions like a Social Security number for your business and is required if you plan to hire employees, operate as a corporation or partnership, or open a business bank account. The IRS issues EINs for free through its online application, and the number is assigned immediately upon approval.9Internal Revenue Service. Get an Employer Identification Number
The IRS recommends forming your entity with the state before applying for an EIN. Wrong order can cause delays. The online tool isn’t available around the clock, and you’re limited to one EIN application per responsible party per day. If you can’t use the online tool, apply by phone, fax, or mail.
Register for Connecticut State Taxes
State entity formation and state tax registration are handled by two different agencies. After filing with the Secretary of the State, register with the Department of Revenue Services to get a Connecticut Tax Registration Number. All new businesses complete this electronically through the myconneCT portal using Form REG-1.10Connecticut State Department of Revenue Services. Register Your Business The portal lets you register for all applicable tax types at once, including the Corporation Business Tax, Sales and Use Tax, withholding tax, and the Pass-Through Entity Tax.11Connecticut State Department of Revenue Services. Applications and Registration
C-Corporations doing business in Connecticut pay the Corporation Business Tax at 7.5% on net income, with a 10% surtax extended through income years beginning on or after January 1, 2028.12Connecticut State Department of Revenue Services. Corporation Business Tax Information A capital base tax also applies, currently at 0.21% and being phased down; the corporation pays whichever calculation is higher.
If you sell taxable goods or services, register for Sales and Use Tax and collect it from customers. The general rate is 6.35%, with higher rates for specific categories like meals, luxury goods, and short-term vehicle rentals, and a reduced 1% rate for computer and data processing services.13Connecticut State Department of Revenue Services. Sales and Use Tax Information
LLCs taxed as partnerships and S-Corporations can elect to pay the Connecticut Pass-Through Entity Tax. The election is optional but can help entity owners work around the $10,000 federal cap on state and local tax deductions. It must be made on a timely filed return and is irrevocable for that tax year. Entities whose annual PE Tax liability reaches $1,000 or more must make quarterly estimated payments.14Connecticut State Department of Revenue Services. Pass-Through Entity Tax Information
Handle Employer Obligations Before Your First Hire
Hiring anyone, part-time or full-time, adds a layer of federal and state requirements. Missing them can produce serious penalties.
On the federal side, withhold and match Social Security tax at 6.2% and Medicare tax at 1.45% on employee wages. Social Security tax applies up to $184,500 in wages for 2026; Medicare has no wage cap.15Social Security Administration. Contribution and Benefit Base You also owe federal unemployment tax (FUTA) on the first $7,000 of each employee’s annual wages.
Connecticut requires you to withhold state income tax based on the employee’s withholding certificate and to pay state unemployment insurance tax. New employers are assigned an initial UI rate that adjusts over time based on claims history. Register for both through myconneCT.
Workers’ compensation insurance is required for any business with one or more employees, and coverage must be in place before your first employee starts work. It covers medical expenses and lost wages for on-the-job injuries. Operating without it is a criminal offense in Connecticut and exposes you to direct liability for all injury costs.
Federal law also requires every employer to verify each new hire’s identity and work authorization using Form I-9. The employee completes their section no later than the first day of paid work, and you must review and verify documentation within three business days of that start date. Keep completed I-9 forms for three years after hire or one year after employment ends, whichever is later. This applies to all employees regardless of citizenship status.
Confirm Local Zoning and Any Licensing You Need
State registration doesn’t clear you to operate at a specific location. Connecticut municipalities have their own zoning regulations, and your location must conform to the local zoning district. Depending on your business type, you may need a zoning permit, site plan approval, or a certificate of occupancy from the local building department. Contact your town or city’s planning and zoning office before signing a lease or starting renovations. Certain business types also require state professional or occupational licenses, which come from the relevant state licensing board rather than the Secretary of the State.
File the Annual Report to Stay in Good Standing
Formation gets the business started. Staying registered requires annual maintenance. The main recurring obligation is the annual report filed with the Secretary of the State, which updates the public record with your current registered agent, principal address, and the names and addresses of officers or members.16Business.CT.gov. File an Annual Report
Deadlines and fees differ by entity type:
- LLCs file between January 1 and March 31 each year, at a fee of $80.
- Corporations file by the last business day of the anniversary month of incorporation, at a fee of $150.17Business.CT.gov. Domestic Annual Report Forms and Fees
Missing the annual report is more than a late fee. The Secretary of the State can administratively dissolve the business, stripping its legal standing. A dissolved entity can’t enforce contracts, file lawsuits, or transact business in Connecticut. Reinstatement is possible and preserves your original formation date, but requires filing all missed reports and paying all overdue fees.18Business.CT.gov. Reinstating a Business Calendar the deadline and treat it as fixed.
Beneficial Ownership Reporting Usually Doesn’t Apply
The Corporate Transparency Act originally required most domestic businesses to report beneficial owners to FinCEN. That requirement has been narrowed. As of March 2025, all entities created in the United States are exempt from BOI reporting. The filing requirement now applies only to foreign entities that have registered to do business in a U.S. state.19FinCEN.gov. Beneficial Ownership Information Reporting If your Connecticut business was formed domestically, no BOI report is required. Foreign reporting companies that registered before March 26, 2025 had an April 25, 2025 deadline; those registering after that date have 30 calendar days from receiving notice that their registration is effective.