What actually happens
An employee who lives in New York and performs work in New Jersey 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 New Jersey withholding starts
New Jersey requires withholding from the first dollar of in-state compensation. There is no de minimis day count to shelter a short assignment. Withholding required from the first dollar of New Jersey-source wages. New Jersey applies a RETALIATORY convenience-of-the-employer rule (P.L.2023 c.125, enacted 7/21/2023, retroactive to 1/1/2023): it sources a nonresident's remote workdays to New Jersey only where the nonresident's HOME state imposes its own convenience rule -- currently Delaware, Nebraska and New York residents. It does NOT apply to Pennsylvania residents (reciprocity) or to Connecticut residents.
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.
New Jersey's convenience rule changes the answer for remote workers
New Jersey applies a convenience-of-the-employer test. If the employee is on a New Jersey payroll but works from New York because they prefer to, New Jersey treats those days as New Jersey-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 New Jersey is covered by New Jersey 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. New Jersey's 2026 taxable wage base is $44,800. The four-factor test in order.
Local taxes are a separate problem
New Jersey: Newark imposes a 1% payroll tax, but it is an EMPLOYER-paid tax on wages, not withheld from employees. New Jersey also has substantial employee-paid state programs withheld through payroll: Unemployment Insurance, Workforce Development, Temporary Disability Insurance and Family Leave Insurance.
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 | New Jersey | New Jersey Division of Taxation |
| Unemployment insurance | New Jersey | New Jersey Department of Labor and Workforce Development |
| Paid family & medical leave | New Jersey | New Jersey runs two employee-funded programs: Temporary Disability Insurance at 0.19% and Family Leave Insurance at 0.23% for 2026 (0.42% combined), on employee wages up to $171,100. Employers also pay a TDI contribution (0.10%-0.75% on the $44,800 employer base); employers do not contribute to FLI. |
Frequently asked
Do New Jersey and New York have a reciprocal tax agreement?
No. There is no reciprocal agreement between New Jersey and New York. New Jersey 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 New Jersey.
Which state's income tax should be withheld?
New Jersey, 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 New Jersey.
Which state gets the unemployment insurance wages?
New Jersey. 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 New Jersey, regardless of residence or where the employer is headquartered.
How many days can an employee work in New Jersey before withholding starts?
There is no safe harbour. New Jersey requires nonresident withholding from the first dollar of compensation earned in the state, so even a single day of in-state work creates an obligation in principle.
Does New Jersey's convenience-of-the-employer rule apply to a remote employee in New York?
It can. If the employee is assigned to a New Jersey office but works from New York for their own convenience, New Jersey sources those days to New Jersey 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.