Connecticut LLC Tax Filing Requirements (2026)

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

Connecticut LLCs are subject to the Business Entity Tax (BET) of $250, due biennially to the Department of Revenue Services (DRS). Depending on federal tax classification, they may also be subject to the Pass-Through Entity Tax (PET) and must comply with federal income tax reporting requirements.

Quick Answer

Primary State Tax: Business Entity Tax (BET): $250 biennially
State Income Tax: No direct LLC income tax; Pass-Through Entity Tax (PET) may apply
Sales Tax: 6.35% (if selling taxable goods/services)
Federal Default: Disregarded entity (single-member) or partnership (multi-member)
Agency: Connecticut Department of Revenue Services (DRS)

Understanding the tax obligations for a Connecticut LLC involves navigating both federal and state-specific requirements. While the federal government generally taxes LLCs as pass-through entities, Connecticut imposes its own unique taxes, such as the Business Entity Tax (BET) and, for certain classifications, the Pass-Through Entity Tax (PET). This guide outlines the key tax filing requirements for LLCs operating in Connecticut for the 2026 tax year.

Federal Tax Classification of an LLC

The Internal Revenue Service (IRS) does not recognize an LLC as a separate tax entity. Instead, an LLC's federal tax treatment depends on the number of members and any elections made by the owners. This is known as the "default" classification:

Single-Member LLC (SMLLC): By default, an SMLLC is treated as a disregarded entity for federal income tax purposes. This means the LLC itself does not file a separate federal income tax return. Instead, its income and expenses are reported on the owner's personal federal income tax return (IRS Form 1040, Schedule C, E, or F). The owner is responsible for self-employment taxes (Social Security and Medicare).
Multi-Member LLC: By default, a multi-member LLC is treated as a partnership for federal income tax purposes. The LLC files an informational return (IRS Form 1065, U.S. Return of Partnership Income) to report its income, gains, losses, deductions, and credits. Each member receives a Schedule K-1 (Partner's Share of Income, Deductions, Credits, etc.) detailing their share, which they then report on their individual Form 1040. Members are also responsible for self-employment taxes.

An LLC can elect to be taxed as a corporation by filing IRS Form 8832, Entity Classification Election. It can further elect to be taxed as an S-corporation by filing IRS Form 2553, Election by a Small Business Corporation. If taxed as an S-corporation, the LLC files IRS Form 1120-S, U.S. Income Tax Return for an S Corporation, and issues Schedule K-1s to its owners. If taxed as a C-corporation, the LLC files IRS Form 1120, U.S. Corporation Income Tax Return, and pays corporate income tax at the entity level.

Most LLCs will need an Employer Identification Number (EIN) from the IRS, even if they are disregarded entities, especially if they have employees or elect corporate taxation.

Connecticut Business Entity Tax (BET)

The primary state-level tax for most Connecticut LLCs is the Business Entity Tax (BET), administered by the Connecticut Department of Revenue Services (DRS). This tax is imposed on certain business entities, including LLCs, for the privilege of doing business in Connecticut.

Tax Amount: The BET is $250.
Filing Frequency: It is due biennially (every two years).
Due Date: The BET is due on or before the last day of the third month following the close of the income year. For LLCs operating on a calendar year, this means March 31st every other year.
Form: The tax is filed using Form OP-424, Business Entity Tax Return.

Even if an LLC has no business activity or income, it may still be required to file and pay the BET if it is registered with the Connecticut Secretary of State. Failure to pay the BET can result in penalties and interest.

Connecticut Pass-Through Entity Tax (PET)

Connecticut imposes a Pass-Through Entity Tax (PET) on certain pass-through entities, including LLCs taxed as partnerships or S-corporations for federal income tax purposes. This tax was enacted in response to the federal limitation on the state and local tax (SALT) deduction for individual taxpayers.

Applicability: The PET applies to pass-through entities that have Connecticut-sourced income. There are certain exceptions and modifications, such as for publicly traded partnerships and entities with only one member who is an individual.
Tax Rate: The tax rate is currently 6.99% of the entity's Connecticut-sourced income.
Filing Requirements: Entities subject to the PET must file Form CT-1065/CT-1120SI, Connecticut Pass-Through Entity Tax Return, and make estimated tax payments throughout the year.
Credit for Owners: Owners of a pass-through entity that pays the PET are generally eligible for a credit against their Connecticut individual income tax or corporation business tax for their share of the PET paid.

The PET is a complex area of Connecticut tax law, and LLCs should consult with a tax professional to determine their specific obligations and potential benefits. More information is available from the DRS on their Pass-Through Entity Tax overview page.

Connecticut Sales and Use Tax

If your Connecticut LLC sells taxable goods or services, it is required to register with the DRS for a Sales and Use Tax Permit. This permit allows the LLC to collect sales tax from customers and remit it to the state.

Registration: Apply for a Sales and Use Tax Permit through the DRS Taxpayer Service Center (TSC).
Tax Rate: The statewide sales and use tax rate is 6.35%.
Filing Frequency: Filing frequency (monthly, quarterly, or annually) depends on the amount of tax collected.
Forms: Sales and use tax returns are typically filed electronically through the TSC.

LLCs engaged in retail sales or providing taxable services must understand what is taxable and their obligations for collection and remittance. Further details can be found on the DRS Sales and Use Taxes overview.

Other Potential Connecticut Taxes

Depending on the nature of its business activities, a Connecticut LLC may be subject to other state taxes:

Corporation Business Tax: If an LLC elects to be taxed as a C-corporation for federal purposes, it will be subject to the Connecticut Corporation Business Tax. This tax is imposed on the net income of corporations and is administered by the DRS. The tax rate and filing requirements are detailed on the DRS Corporation Business Tax page.
Employer Withholding Tax: If the LLC has employees, it must register with the DRS for employer withholding tax. This involves withholding Connecticut income tax from employee wages and remitting it to the DRS on a regular basis. Information on this can be found on the DRS Withholding Tax overview.
Estimated Income Tax: Individual owners of LLCs (especially those taxed as disregarded entities or partnerships) may need to pay estimated Connecticut income tax if they expect to owe more than a certain amount in tax for the year. This is typically done through quarterly payments. The DRS provides guidance on estimated income tax.
Unemployment Insurance Tax: If the LLC has employees, it will also be subject to unemployment insurance taxes, administered by the Connecticut Department of Labor.
Local Property Taxes: LLCs that own real estate or tangible personal property in Connecticut may be subject to local property taxes assessed by the city or town where the property is located.

It is crucial for LLC owners to identify all applicable taxes based on their specific business operations and location within Connecticut. For a comprehensive overview of all business taxes, refer to the LegalGlass business tax hub.

Key Filing Dates and Forms

Here is a summary of common Connecticut tax forms and their due dates for LLCs:

Tax/Form	Description	Due Date	Agency
Form OP-424	Business Entity Tax Return ($250)	Biennially, by March 31st (for calendar year LLCs)	DRS
Form CT-1065/CT-1120SI	Pass-Through Entity Tax Return	Generally March 15th (for calendar year LLCs)	DRS
Sales and Use Tax Return	Reporting and remitting sales tax collected	Monthly, quarterly, or annually (varies)	DRS
Form CT-941	Connecticut Withholding Tax Return	Quarterly (or more frequently, varies)	DRS
Form CT-1040ES	Estimated Connecticut Income Tax for Individuals	Quarterly (April 15, June 15, Sept 15, Jan 15)	DRS
IRS Form 1040, Schedule C/E/F	Individual income tax reporting for SMLLCs	April 15th (federal)	IRS
IRS Form 1065	U.S. Return of Partnership Income (multi-member LLCs)	March 15th (federal)	IRS
IRS Form 1120-S	U.S. Income Tax Return for an S Corporation	March 15th (federal)	IRS

It is important to note that if a due date falls on a weekend or holiday, the deadline is typically extended to the next business day. Penalties and interest can apply for late filings or payments. The DRS offers an online Tax Calendar for specific dates.

Maintaining Compliance

To ensure ongoing compliance, Connecticut LLCs should:

Obtain an EIN: Secure a federal EIN from the IRS.
Register with DRS: Register the business with the Connecticut Department of Revenue Services for all applicable taxes (BET, PET, sales tax, withholding, etc.). This can often be done through the DRS Taxpayer Service Center (TSC).
Keep Accurate Records: Maintain detailed financial records of all income, expenses, and transactions.
Consult a Professional: Due to the complexity of tax laws, especially regarding the PET and federal elections, it is advisable to consult with a qualified tax professional or accountant familiar with Connecticut tax law.
Monitor Changes: Tax laws can change frequently. Regularly check the DRS website for updates and new guidance.

Beyond tax filings, Connecticut LLCs must also file an annual report with the Connecticut Secretary of State to maintain good standing. This is a separate requirement from tax filings.

Frequently Asked Questions

What is the main tax an LLC pays in Connecticut?

The primary state-level tax for most Connecticut LLCs is the Business Entity Tax (BET), which is $250 due biennially (every two years). This tax is administered by the Connecticut Department of Revenue Services (DRS).

Does a Connecticut LLC pay state income tax?

Connecticut does not impose a direct state income tax on LLCs themselves. Instead, profits and losses typically 'pass through' to the owners' personal income tax returns. However, if the LLC elects S-corporation status, it may be subject to the Pass-Through Entity Tax (PET).

What is the Connecticut Pass-Through Entity Tax (PET)?

The PET is an entity-level tax imposed on pass-through entities, including LLCs taxed as partnerships or S-corporations, with certain exceptions. It is calculated on the entity's Connecticut-sourced income and is intended to provide a state tax deduction for owners, particularly in response to federal SALT deduction limitations.

When is the Connecticut Business Entity Tax due?

The Business Entity Tax (BET) is due biennially (every two years) on or before the last day of the third month following the close of the income year. For LLCs with a calendar year-end, this means March 31st every other year. The tax is $250.

Does a Connecticut LLC need to collect sales tax?

If a Connecticut LLC sells taxable goods or services, it must register with the Department of Revenue Services (DRS) for a Sales and Use Tax Permit and collect and remit sales tax. The current statewide sales tax rate is 6.35%.

What federal taxes apply to a Connecticut LLC?

Federally, a single-member LLC is taxed as a disregarded entity (sole proprietorship) by default, and a multi-member LLC as a partnership. Owners report profits/losses on their personal tax returns (Form 1040, Schedule C, E, or F). LLCs can elect to be taxed as a C-corporation or S-corporation by filing IRS Form 2553 or 8832.

Related Resources

Sources

Connecticut Department of Revenue Services (DRS) - Business Entity Tax Overview.
Connecticut Department of Revenue Services (DRS) - Pass-Through Entity Tax Overview.
Connecticut Department of Revenue Services (DRS) - Sales and Use Taxes Overview.
Connecticut Department of Revenue Services (DRS) - Corporation Business Tax Overview.
Connecticut Department of Revenue Services (DRS) - Withholding Tax Overview.
Connecticut Department of Revenue Services (DRS) - Estimated Income Tax Overview.
Connecticut Department of Revenue Services (DRS) - DRS Tax Calendar.
Internal Revenue Service (IRS) - Limited Liability Company (LLC).
Internal Revenue Service (IRS) - S Corporations.
Internal Revenue Service (IRS) - Partnerships: Filing Requirements.
Internal Revenue Service (IRS) - Sole Proprietorships: Filing Requirements.
Connecticut General Statutes - Chapter 207 - Business Entity Tax.
Connecticut General Statutes - Chapter 208 - Corporation Business Tax.
Connecticut General Statutes - Chapter 228a - Pass-Through Entity Tax.
Connecticut General Statutes - Chapter 229 - Income Tax.

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 the IRS before acting.