What actually happens
An employee who lives in New York and performs work in Connecticut sits in two tax systems at once. The residence state claims the right to tax all of a resident's income wherever earned; the work state claims the right to tax income sourced within its borders. Absent an agreement, both claims stand, and the conflict is resolved after the fact through a credit on the resident return rather than up front in payroll.
When Connecticut withholding starts
Connecticut applies a de minimis test of 15 working days before nonresident withholding begins. Per Circular CT (IP 2026(1)): 'If a nonresident employee performs personal services for employment purposes in Connecticut for 15 days or less, this compensation is not Connecticut-sourced income and is not subject to Connecticut income tax.' If the employee ends up exceeding 15 days, withholding applies retroactively to ALL Connecticut compensation. Tax Foundation separately reports a >$6,000 nonresident filing threshold.
The trap is that thresholds are usually retroactive to the first day once crossed. An employee who spends 40 days in a 30-day-threshold state does not owe tax on 10 days; they owe it on all 40, and the employer is the one who failed to withhold.
Connecticut's convenience rule changes the answer for remote workers
Connecticut applies a convenience-of-the-employer test. If the employee is on a Connecticut payroll but works from New York because they prefer to, Connecticut treats those days as Connecticut-source income even though no work was physically performed there. Only genuine employer necessity moves the sourcing. How the test is applied.
Unemployment insurance goes to one state only
Income tax can be split between states. Unemployment insurance cannot. Under the localization test used by every state, an employee whose services are performed entirely in Connecticut is covered by Connecticut for unemployment purposes, and all wages are reported there — regardless of where they live, where you are headquartered, or which state's income tax you withhold. Connecticut's 2026 taxable wage base is $27,000. The four-factor test in order.
Local taxes are a separate problem
New York: New York City imposes a resident personal income tax and Yonkers imposes a resident income tax surcharge plus a nonresident earnings tax -- all withheld through payroll (see Form IT-2104.1 for nonresident allocation). The Metropolitan Commuter Transportation Mobility Tax (MCTMT) is an employer-paid tax on payroll in the MTA region, not withheld from employees.
What you have to register for
| Obligation | State | Agency |
|---|---|---|
| Income tax withholding | Connecticut | Connecticut Department of Revenue Services |
| Unemployment insurance | Connecticut | Connecticut Department of Labor |
| Paid family & medical leave | Connecticut | Connecticut Paid Leave is 100% employee-funded at 0.50% of wages up to the Social Security wage base ($184,500 for 2026). The CT Paid Leave Authority held the rate at 0.50% for 2026. |
Frequently asked
Do Connecticut and New York have a reciprocal tax agreement?
No. There is no reciprocal agreement between Connecticut and New York. Connecticut taxes wages earned in the state by nonresidents, and New York taxes the same wages as resident income while allowing a credit for tax paid to Connecticut.
Which state's income tax should be withheld?
Connecticut, as the state where the work is performed. New York also taxes the income as a resident, but the employee claims a credit on the New York return for tax paid to Connecticut.
Which state gets the unemployment insurance wages?
Connecticut. Unemployment coverage is never split between states for a single job. The localization test assigns the whole job to the state where services are performed, which here is Connecticut, regardless of residence or where the employer is headquartered.
How many days can an employee work in Connecticut before withholding starts?
Connecticut applies a de minimis test of 15 working days. Once the limit is crossed, most states require withholding on all in-state wages for the year, not just the excess.
Does Connecticut's convenience-of-the-employer rule apply to a remote employee in New York?
It can. If the employee is assigned to a Connecticut office but works from New York for their own convenience, Connecticut sources those days to Connecticut anyway. The rule is displaced only where the remote arrangement is a genuine necessity of the employer, which is a facts-and-circumstances test you should document contemporaneously.