File Your Connecticut Business Taxes Online with Confidence
X.TAX ensures accurate filing for all CT business tax forms while maximizing your savings.
File CT Business Tax Forms with Ease
Know Connecticut deadlines and claim all eligible exemptions and credits.
Connecticut offers a competitive 7.5% corporate income tax rate. The state provides various tax credits and incentives, such as the Research and Development Tax Credit and the Urban and Industrial Sites Reinvestment Tax Credit. This supportive landscape fosters economic growth and innovation, making Connecticut an attractive hub for diverse businesses.
Find All CT Business Tax Forms in One Place
From corporations to LLCs, partnerships, estates, and trusts, we’ve got you covered.
Corporations
- CT-1120: Corporation Business Tax Return for C Corporations
- CT-1120A: Apportionment Computation for Multistate Corporations
- CT-1120K: Corporation Business Tax Credit Schedule
Partnership and LLC
- CT-1065: Pass-Through Entity Tax Return
- CT-1120SI: Tax Return for S Corporations
- CT-1065/CT-1120SI ES: Estimated Payment Coupon
Estate and Trust Forms
- CT-990T: Exempt Organization Business Tax Return
Additional Forms
- CT-1120CU: Combined Unitary Tax Return
- CT-5: Request for a Six-Month Extension
- Biennial Report: Required for corporations
Steps to File CT Business Taxes
File confidently in just four steps with X.TAX.
Create an Account
Set up your profile securely.
Upload Your Information
Enter your income, expenses, and tax forms.
Review for Errors
Use smart tools to verify accuracy.
Submit to the State
File with one click and track your submission.
Key CT Business Tax Deadlines
Keep track of Connecticut deadlines with X.TAX reminders.
| Business Type | Forms | Due Date |
|---|---|---|
| Corporations | IA 1120: Iowa Corporation Income Tax Return | April 15, 2025 |
| IA 1120A: Short Form for C Corporations | April 15, 2025 | |
| IA 1120S: Iowa Income Tax Return for S Corporations | April 15, 2025 | |
| Partnership & LLCs | IA 1065: Iowa Partnership Income Tax Return | April 15, 2025 |
| PTET Election: Pass-Through Entity Tax Election | April 15, 2025 | |
| Estates and Trusts | IA 990: Iowa Income Tax Return for Estates and Trusts | April 15, 2025 |
| Additional Forms | Form 32-028: Sales and Use Tax Return | Due on the last day of the month following the reporting period |
| IA 1040ES: Estimated Tax Payment Voucher | Due quarterly on April 15, June 15, September 15, and January 15 (following year) | |
| Biennial Report: Required for corporations | Due every two years by April 1 |
Claim CT Tax Exemptions for your Biz Tax
Take full advantage of Connecticut’s tax credits and exemptions.
Sales and Use Tax Exemptions
Corporate Income Tax Exemptions
Property Tax Exemptions
Digital Media and Film Incentives
Capital Equipment Tax Exemptions
X.TAX- Your Connecticut Tax Filing Solution
Filing your CT business taxes has never been easier.
Audit Protect
- Detect and address audit triggers early using Data Signals.
- Manage audits efficiently with full support from X.TAX.
RiskScore
- Track your IRS account status in real time.
- Receive alerts about potential filing issues or unresolved balances.
AItomatic Filings
- Let CPAs handle your filings for $250.
- Includes audit protection for a full year.
QuickBooks Integration
- Import financial data directly for faster, error-free filings.
Why CT Businesses Trust X.TAX
Hear from businesses across Connecticut who rely on X.TAX.
Connecticut Business Tax FAQs
Clear answers to your most pressing CT Biz Tax questions.
What is the best e-filing software for Connecticut business taxes?
X.TAX is optimized for Connecticut’s tax system, offering secure filing and compliance tools.
What forms do I need to file for CT business taxes?
X.TAX provides all necessary forms for corporations, partnerships, estates, and trusts. For more information, see the list above or visit our website.
What are the important deadlines for Connecticut business taxes?
Corporate and partnership returns are due April 30. Estimated payments are made quarterly, and biennial reports are due by April 1 of even years.
What exemptions can CT businesses claim?
Connecticut businesses benefit from sales tax exemptions for manufacturing equipment, property tax relief for new investments, and film/media tax incentives.
How does X.TAX ensure filing accuracy?
X.TAX uses smart tools to verify all filings and ensure compliance with Connecticut tax laws.
Is X.TAX secure for CT business tax filings?
Absolutely. We use advanced encryption to protect all your data and ensure safe submissions.
