Sole Proprietorship in Connecticut (2026)

Fact-checked by the LegalGlass editorial team against primary sources · Published Aug 6, 2026 · Last updated Aug 6, 2026

A Connecticut sole proprietorship requires no state formation filing - you become one automatically by doing business on your own. If you use a business name other than your legal name, you file a trade name (DBA) certificate with the town clerk. You report profit on IRS Schedule C, pay the 15.3% self-employment tax, and register with the Department of Revenue Services for sales tax if you sell taxable goods.

What a Sole Proprietorship Is in Connecticut

A sole proprietorship is the simplest way to run a business: one individual owns and operates it, and the law does not treat the business as separate from the owner. In Connecticut there is no formation document to file with the Secretary of the State and no franchise or organization fee. The moment you begin offering goods or services for profit by yourself, you are a sole proprietor by default. That simplicity is the structure's biggest advantage and its biggest drawback: it is cheap and fast to start, but it provides no liability shield.

Because the business and the owner are the same legal person, the proprietor keeps all profit, makes every decision, and is personally responsible for every debt and obligation. If you want a separate legal entity, compare this structure with an LLC and the single-member LLC approach, or read the national how to form an LLC hub.

No State Formation Filing Required

Unlike an LLC or corporation, a sole proprietorship is not created by filing articles of organization or paying a state fee. There is no entity to register with the Secretary of the State, no registered agent to appoint, and no annual report to file at the entity level. This keeps administrative overhead near zero. The trade-off is that the owner has no registered legal entity and no separation between personal and business assets - a creditor of the business can reach the owner's personal property, and a personal creditor can reach the business. Keeping thorough records and a separate business bank account is still good practice, but it does not create legal separation on its own.

Trade Name (DBA) Registration with the Town Clerk

If you operate under any name other than your own full legal name - for example, "Nutmeg Landscaping" instead of "Jane Smith" - Connecticut law requires you to file a trade name certificate with the town clerk in each town where you transact business. This is Connecticut's version of a "doing business as" or DBA registration, governed by the trade name statute in the General Statutes. The certificate is filed locally, not with the state, and the fee is set by the town; it is generally a modest, one-time charge.

Registering a trade name lets you open a bank account and sign contracts under the business name and puts the public on notice of who owns it. It does not give you exclusive rights to the name or any trademark protection. To protect a brand, look at state or federal trademark registration and the trademark and DBA overviews. A trade name and a trademark are different tools that solve different problems.

EIN and Taxes for a Connecticut Sole Proprietor

A sole proprietor with no employees may use a Social Security number for tax purposes, but a free federal EIN is required once you hire employees or owe certain excise taxes, and many banks ask for one to open a business account. Getting an EIN also lets you avoid putting your Social Security number on client forms.

For federal income tax, you report business income and expenses on Schedule C attached to your Form 1040, and net profit flows to your personal return. On that profit you owe self-employment tax of 15.3% (12.4% Social Security up to the annual wage base plus 2.9% Medicare), calculated on Schedule SE; you deduct half of it as an adjustment to income. Because no employer withholds tax for you, you generally make quarterly estimated payments to the IRS and to Connecticut. At the state level, net profit is subject to the Connecticut personal income tax. See self-employment tax and business tax for how these pieces fit together, and Connecticut LLC tax filing if you later form an entity.

Sales Tax, Licenses, and Permits

If you sell taxable goods or certain services, you must register with the Connecticut Department of Revenue Services (DRS) for a Sales and Use Tax Permit through the myconneCT portal before making sales, and then collect and remit sales tax on schedule. Connecticut charges a fee for the sales tax permit, so confirm the current amount and renewal cycle with DRS. Connecticut has no single general "business license" that every business needs, but many activities and professions - food service, contracting, childcare, health and beauty, and others - require specific state or local licenses. Check both your town and the relevant state agency for your line of work, and review the Connecticut business license and national business license guides.

Liability and When to Form an LLC

The defining limitation of a sole proprietorship is unlimited personal liability. Because there is no separate entity, a business debt or lawsuit can reach your home, savings, and other personal assets. Insurance helps, but it does not create the legal separation that an entity provides. Many Connecticut owners start as sole proprietors and convert once revenue, contracts, or risk grow.

Forming an LLC creates that separation: you file articles of organization, appoint a registered agent, adopt an operating agreement, and keep business and personal finances apart. An LLC can also elect S-corporation tax treatment as it grows. When the risk of the work, the size of contracts, or the presence of employees increases, the liability shield usually justifies the modest filing cost. If you eventually wind down, see how to dissolve an LLC in Connecticut.

Frequently Asked Questions

Do I have to register a sole proprietorship in Connecticut?

No state formation filing is required - you are a sole proprietor by default. If you use a business name other than your legal name, you must file a trade name certificate with the town clerk where you operate.

Where do I file a DBA in Connecticut?

With the town clerk in each town where you conduct business, not with the Secretary of the State. The fee is set locally and is usually modest and one-time.

Do I need an EIN as a Connecticut sole proprietor?

Not always. Without employees you can use your Social Security number. You need a free EIN if you hire employees, owe certain excise taxes, or a bank requires one for a business account.

What taxes does a Connecticut sole proprietor pay?

Federal income tax via Schedule C, 15.3% self-employment tax via Schedule SE, and Connecticut personal income tax on net profit. Sellers of taxable goods also collect and remit Connecticut sales tax.

Is a sole proprietor personally liable for business debts?

Yes. The business is not a separate entity, so the owner is personally responsible for all debts and lawsuits. An LLC or corporation adds a liability shield.

How do I switch to an LLC?

File Articles of Organization with the Secretary of the State, appoint a registered agent, get an EIN, and move contracts and accounts into the LLC for limited liability going forward.

Related

• How to form an LLC (cluster hub)
• How to form an LLC in Connecticut
• Sole proprietorship in Kentucky (sibling)
• What is a DBA?
• How to get an EIN
• Self-employment tax explained

Sources

1. IRS - Sole Proprietorships.
2. IRS - Schedule C (Profit or Loss from Business).
3. IRS - Self-Employment Tax (15.3%).
4. IRS - Estimated Taxes.
5. IRS - Get an Employer Identification Number (free EIN).
6. Connecticut General Assembly - Conn. Gen. Stat. Chapter 617, Trade Names.
7. Connecticut DRS - Department of Revenue Services (state tax registration).
8. Connecticut DRS - Getting Started in Sales and Use Taxes (permit).
9. Connecticut DRS - myconneCT taxpayer portal.
10. Connecticut Secretary of the State - Business Services.
11. Connecticut - Department of Economic and Community Development (starting a business).
12. Connecticut General Assembly - Conn. Gen. Stat. Chapter 613, LLC Act.
13. IRS - Limited Liability Company (LLC).
14. Connecticut DRS - Individual Income Tax.
15. IRS - Business Structures.

LegalGlass provides general information for educational purposes and is not a law firm or a substitute for advice from a licensed attorney or tax professional. Laws, fees, and thresholds change; verify current requirements with the Connecticut Department of Revenue Services and your town clerk before acting.