Connecticut income tax guide for individuals and businesses
A plain-English overview of Connecticut individual and business taxes for 2026: rates, forms, deadlines, sales tax, payroll and multi-state rules, with CPA help when you need it.
Connecticut at a glance
| Individual income tax | Graduated, top rate about 6.99% |
|---|---|
| Main resident return | Form CT-1040 |
| Business taxes | Corporation business tax, top rate about 7.5% plus a surtax for larger companies. A pass-through entity tax applies to most partnerships and S corporations. |
| Sales tax | About 6.35% state rate |
| Individual return due | April 15 |
| Tax agency | Connecticut Department of Revenue Services |
| Wage reciprocity | No wage reciprocity agreements are commonly listed for this state |
| "Convenience of the employer" rule | Yes. This state may tax a nonresident who works from home for an employer based here. |
Individuals
Connecticut has a graduated individual income tax (about 6.99% at the top). Residents generally file Form CT-1040 and start from their federal income.
Nonresidents and part-year residents who earn income from Connecticut sources (for example wages for work performed in Connecticut, rental property or a business here) generally file the nonresident or part-year version of the return or a schedule. Your home state normally gives a credit for tax paid to Connecticut, so the same income is rarely taxed twice.
Good to know: Connecticut applies a "convenience of the employer" rule for people who work from home for a Connecticut employer from another state.
Businesses
Entity-level taxes: Corporation business tax, top rate about 7.5% plus a surtax for larger companies. A pass-through entity tax applies to most partnerships and S corporations.
Pass-through businesses. S corporations, partnerships and most LLCs pass income to their owners, who report it on personal returns. Many states, including a large number of those that tax income, offer an elective pass-through entity tax (PTET) that can help work around the federal limit on deducting state taxes. Ask us whether it fits Connecticut and your situation.
Sales tax. About 6.35% state rate. After the Wayfair decision, out-of-state sellers can owe sales tax once their sales into Connecticut pass the state's threshold, even with no office there.
Payroll. Employers must register for state income tax withholding (where the state has an income tax) and for state unemployment insurance before the first payroll, and report new hires. Workers' compensation insurance is also required in most cases.
Annual filings. Most states also require corporations and LLCs to file a yearly report or pay a fee to the Secretary of State.
Working in more than one state
Connecticut is not commonly listed as having wage reciprocity with other states, so people who live in one state and work in another usually file nonresident returns and claim a credit at home.
Connecticut applies a "convenience of the employer" rule: wages of a nonresident who works remotely for an employer based in Connecticut can be taxed here for days worked from home, unless the employer required the remote work.
Working or living in more than one state, or moving during the year? See our multi-state tax guide.
Compliance calendar snapshot
| When | What |
|---|---|
| January 15, April 15, June 15, September 15 | Federal estimated tax payments. Most states with an income tax follow similar dates. |
| April 15 | Connecticut individual return due date (calendar-year filers) |
| Monthly or quarterly, usually the 20th of the next month | State sales tax returns and payroll withholding deposits, depending on volume |
| Quarterly (end of month after quarter) | State unemployment insurance and withholding reconciliation returns |
| Yearly, on the entity's anniversary or by a fixed date | Secretary of State annual report or franchise fee |
Common questions
What is the Connecticut income tax rate for 2026?
Connecticut has graduated rates with a top rate of about 6.99%. Rates, brackets and credits change, so confirm with the Connecticut Department of Revenue Services.
Which form do I file for Connecticut income tax?
Residents generally file Form CT-1040. Nonresidents and part-year residents use the nonresident or part-year version or a schedule. The state agency's website has the current forms and instructions.
Do I need to file a Connecticut return if I live in another state?
If you earned income from Connecticut sources (wages for work performed here, rental property, or a business or partnership interest), you may need to file in Connecticut even if you live elsewhere. Your home state usually gives a credit for tax paid to another state.
Does Connecticut have reciprocity with other states?
Connecticut is not commonly listed as having wage reciprocity. Reciprocity applies only to wages and there are exceptions, so confirm before you stop withholding.
What business taxes apply in Connecticut?
Corporation business tax, top rate about 7.5% plus a surtax for larger companies. A pass-through entity tax applies to most partnerships and S corporations. Sales tax, payroll withholding and unemployment insurance may also apply.
General information only, for tax year 2026. Rates, forms and rules change and have many exceptions. Confirm with the state agency or contact us before you act. Rates shown are approximate top or flat rates.
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