Connecticut Business Taxes Explained for New Owners

Starting a business in Connecticut means navigating a specific set of tax obligations. Whether you're forming an LLC, S-corporation, or partnership, understanding Connecticut business taxes upfront prevents costly mistakes and keeps your business compliant. This guide breaks down the tax landscape you'll encounter as a new business owner in the state.

Connecticut Has No State Business License, But Taxes Still Apply

Unlike many states, Connecticut does not require a general state business license. However, this does not mean you can avoid taxes. Depending on your industry, you may need specialized licensing from agencies like the Department of Consumer Protection, Department of Public Health, or Connecticut Insurance Department. Check the Business.CT.gov New Business Checklist and eLicense system to determine what applies to your business.

The absence of a state license requirement does not replace your core Connecticut business tax obligations. Every business selling taxable goods or services must obtain a Sales and Use Tax Permit from the Connecticut Department of Revenue Services, and annual reporting is required for LLCs and corporations.

Sales and Use Tax: The First Tax Most Businesses Pay

Connecticut's sales tax rate is 6.35 percent on most taxable goods and some services. If your business sells anything subject to this tax, you must register for a Sales and Use Tax Permit with the Connecticut Department of Revenue Services (DRS). The registration fee is $100, and you must display the permit at each location where you operate.

The key word here is "taxable." Not all goods and services are subject to sales tax in Connecticut. For example, Connecticut taxes tangible goods and a list of specific services, including business analysis, management consulting and public relations services, motor vehicle towing and repair, while many other services are not taxable. Software licenses, digital goods, and certain services may or may not be taxable depending on how they are structured. Review the DRS Sales Tax Information page to determine if you owe sales tax on your specific offerings.

Once registered, DRS assigns your filing frequency (monthly, quarterly, or annual), and Form OS-114 is due on or before the last day of the month following the end of each filing period. You file a return for every period, even if no tax is due. You collect sales tax from customers, hold it, and remit it to Connecticut on the due date. Failing to remit collected sales tax is treated seriously by the state.

Understanding Connecticut LLC Taxes

When you form an LLC in Connecticut, the state does not automatically assign a tax structure. By default, the IRS and Connecticut treat a single-member LLC as a sole proprietorship for tax purposes, and a multi-member LLC as a partnership. However, you can elect to be taxed as a C-corporation or S-corporation instead.

This distinction matters because it determines which Connecticut business taxes you pay. Here is how the major tax structures work for Connecticut LLCs:

LLC Taxed as a Partnership or Sole Proprietorship

If your LLC is taxed as a partnership or sole proprietorship, Connecticut does not impose a franchise tax or annual privilege tax on the LLC itself. Instead, the individual members report business income on their personal Connecticut tax returns and pay personal income tax on their share of the profits.

Connecticut personal income tax uses progressive rates across seven tax brackets, ranging from 2 percent to 6.99 percent, depending on your total income. This is in addition to federal income tax.

LLC Taxed as an S-Corporation

An S-corporation is a pass-through entity: the corporation itself does not pay income tax, but the owners report their share of profits on their personal tax returns. Connecticut taxes S-corporations similarly to partnerships at the individual level.

LLC Taxed as a C-Corporation

If you elect to have your LLC taxed as a C-corporation for Connecticut purposes, the LLC itself pays the Connecticut Corporation Business Tax. This tax is calculated as 7.5 percent of the LLC's apportioned net income, or the capital base tax, whichever produces the greater tax. The capital base tax is being phased out (0.16 percent for 2026, 0.11 percent for 2027, and none from 2028). There is a minimum tax of $250 per year.

Additionally, C-corporations with total income of $100 million or more (or those filing as part of a combined unitary group) owe a 10 percent surtax on top of the base rate. After paying the corporate tax, owners pay personal income tax again on any dividends received, creating double taxation.

The Pass-Through Entity Tax Election: A Possible Savings Strategy

Connecticut offers an optional Pass-Through Entity Tax (PTE) election that may benefit some LLC owners. If your LLC is taxed as a partnership or S-corporation, you can elect the PTE with the Connecticut Department of Revenue Services. The election is made annually and is irrevocable for that specific tax year.

Under this election, the entity itself pays the Connecticut Pass-Through Entity Tax. The election is made by checking the box on a timely filed Form CT-1065/CT-1120SI, and the entity then files Form CT-PET. Whether the election makes sense depends on your income level, ownership structure and your owners' own federal and Connecticut tax positions.

This is a complex decision. Discuss the PTE election with a Connecticut CPA or tax attorney to determine if it reduces your overall Connecticut business taxes.

Annual Reporting Requirements and Fees

All LLCs and corporations formed in Connecticut must file an Annual Report with the Secretary of the State every year, separate from income tax filings with the DRS.

For LLCs, the Annual Report fee is $80. The report is filed with the Connecticut Secretary of the State through Business.CT.gov. The state does not publish a single flat deadline for all LLCs. Instead, each LLC's Business.CT.gov account shows its own next due date. Common practice is that LLCs are due between January 1 and March 31 each year, but confirm your specific due date in your account.

For corporations, the Annual Report fee is $150, and corporations also file each year with the Secretary of the State. The due date for each corporation appears in its account and commonly falls in the anniversary month of formation.

These annual reports maintain your good standing with the state. Failing to file can eventually lead to dissolution of your entity by the state, which has serious consequences for personal liability protection.

Estimated Quarterly Taxes

Connecticut business taxes are often paid throughout the year rather than as one lump sum. If you operate as a sole proprietor or partnership, you must make estimated personal income tax payments to Connecticut quarterly. If you operate as a C-corporation, you must make estimated corporate tax payments quarterly.

The timing of estimated payments is critical. Missing estimated payment deadlines can result in penalties and interest. If your business income is unpredictable, many owners make estimated payments based on their prior year's tax liability and then settle the difference when they file their actual return.

Use the Connecticut Department of Revenue Services website to determine your estimated payment schedule and the exact due dates. For individuals, estimated income tax installments are due April 15, June 15, September 15 and January 15. Corporation Business Tax estimates fall on the 15th day of the third, sixth, ninth and twelfth months of the income year and are required only if the estimated tax exceeds $1,000.

Corporate Income Tax and the Minimum Tax

Connecticut's Corporation Business Tax applies to C-corporations and to LLCs that elect to be taxed as corporations. The rate is 7.5 percent of apportioned net income, or the capital base tax, whichever is greater. The capital base tax rate is phasing out (0.16 percent for 2026, 0.11 percent for 2027, none from 2028). The minimum tax is $250 per year.

Even a new business with zero or minimal profit owes the $250 minimum. This applies from the year the corporation or LLC is formed. Plan for this cost when budgeting for a new Connecticut business.

The capital base calculation can be complex, particularly for businesses that operate across multiple states or own significant assets. Many business owners hire a Connecticut CPA to calculate apportioned income and capital base correctly and ensure they pay the correct tax amount.

Common Connecticut Business Tax Mistakes to Avoid

Mistake 1: Assuming LLC formation means no taxes. Many new owners form an LLC and believe they are tax-exempt. An LLC is simply a legal structure for liability protection. Your tax obligations depend on your election and business activities. Expect to pay Connecticut business taxes from day one.

Mistake 2: Forgetting the $100 Sales Tax Permit fee. If you sell taxable goods or services, you need this permit. The $100 registration fee with the DRS is a one-time cost that is sometimes overlooked during startup.

Mistake 3: Not remitting sales tax on schedule. You must collect and remit sales tax on the monthly, quarterly, or annual schedule assigned by the DRS. Commingling sales tax with business revenue is a common error that creates serious liability later.

Mistake 4: Missing the annual report deadline. The annual report to the Secretary of the State is separate from your income tax filing to the DRS. Missing it can dissolve your LLC and expose owners to personal liability. Mark the deadline in your calendar.

Mistake 5: Not estimating quarterly payments. Waiting to pay all income tax when you file your annual return often results in penalties and interest. Make estimated quarterly payments based on your expected annual income.

Getting Help: Connecticut Tax Resources

Connecticut business taxes are specific to the state, and the rules vary significantly based on your business structure and industry. Consider consulting these resources and professionals:

• Connecticut Department of Revenue Services: https://portal.ct.gov/drs - Start here for sales tax, income tax, and filing deadlines.
• Business.CT.gov: https://business.ct.gov/ - Register for permits, file annual reports, and access the Business Services Division.
• Connecticut Small Business Development Center (CTSBDC): https://ctsbdc.uconn.edu/ - Free business counseling and training.
• SBA Connecticut District: https://www.sba.gov/district/connecticut - Federal resources for small businesses.
• A Connecticut CPA or Tax Attorney: For tax planning, estimated payment calculations, and PTE elections, hiring a qualified professional is worth the investment.

Informational Disclaimer

This guide is informational content about Connecticut business taxes and is not legal or tax advice. Tax law is complex and changes frequently. The specific Connecticut business taxes you owe depend on your business structure, industry, location, and income level. Before making decisions about your business tax strategy, consult a qualified Connecticut CPA, tax attorney, or other qualified tax professional. This guide is accurate as of September 2026 but does not replace professional advice tailored to your situation.

Starting a business in Connecticut requires attention to both state and federal taxes, accurate record-keeping, and timely filing. Understanding these obligations from the beginning sets your business up for long-term compliance and success.