Multi-State Payroll Taxation: Which State Gets the Withholding?

An employee who lives in one state and works in another creates an immediate question for payroll: which state's income tax do you withhold? The general rule is straightforward. The exceptions are where the penalties live.

The General Rule

Withholding normally follows where the work is performed, not where the employee lives. An employee living in one state and commuting to an office in another is generally subject to withholding in the work state.

That is the starting point, not the end of the analysis, because the state of residence usually also asserts a claim on its residents' entire income regardless of where it was earned. Two states, one paycheque — and the resolution depends on the relationship between them.

Reciprocity Agreements

Many neighbouring states have reciprocity agreements: the work state agrees not to tax residents of the other, so the employer withholds only for the residence state. This is why cross-border commuting in some regions is administratively simple and in others is not.

Reciprocity is never automatic. It requires the employee to file an exemption certificate with the employer for the work state. Without that certificate on file, the employer should withhold for the work state — and employers who take the employee's word for it, without the form, are the ones who lose the argument in an audit.

Agreements are added and terminated by legislation. [VERIFY: current list of state reciprocity agreements and the exemption certificate required for each — source: the revenue department of each state involved] rather than relying on a list compiled in a prior year.

Credits for Taxes Paid to Another State

Where no reciprocity exists, the usual mechanism is a credit: the residence state taxes the income but grants a credit for tax paid to the work state. That resolves double taxation at the employee's return, not in payroll — so the employer may still be obliged to withhold for the work state while the residence state waits to be settled on the individual return.

Employees are frequently surprised by this, and payroll gets the call. Being able to explain the mechanism clearly prevents most of those conversations becoming complaints.

Remote and Hybrid Work

Remote work turned this from an edge case into a routine problem. An employee working from home in a different state from the employer's office may create withholding obligations — and potentially a business tax presence, or nexus — in the state where they sit.

Several issues follow that payroll cannot resolve alone:

• Withholding for a new state generally requires registering with that state as an employer first.
• Unemployment insurance. State unemployment tax follows its own sourcing rules, which do not always match income tax withholding.
• Local taxes. Some jurisdictions impose city or county taxes on top of state tax.
• "Convenience of the employer" rules. A few states tax remote employees of in-state employers as though they worked in-state, even when they never set foot there.

The last of those is the one that produces unexpected assessments, and it is state-specific. Confirm the treatment for each state in which you have remote staff.

Travelling Employees

Employees who work temporarily in other states — sales staff, field engineers, trainers — can trigger withholding obligations once they exceed a state's threshold. Thresholds vary: some states use days present, some use wages earned, and some have no threshold at all.

Tracking this requires travel data that payroll usually does not receive. In practice the control is a policy requiring employees to report multi-state work days, and a periodic reconciliation against expense reports.

Where Employers Actually Get Caught

• Assuming residence always governs. It usually does not.
• Applying reciprocity without the certificate. The exemption is the employee's to claim, on a form.
• Missing registration. Withholding for a state you are not registered in creates its own problem.
• Ignoring local taxes. They are easy to miss and cheap to fix in advance, expensive to fix late.
• Treating a remote hire as a payroll-only change. It can be a tax-presence decision for the whole business.

Practical Controls

Collect a current work location — not just a mailing address — at hire and at every change. Require the relevant exemption certificate before applying reciprocity. Register before you withhold. And review remote arrangements annually, because employees relocate quietly and tell HR long after the fact.

Getting Work Location Data You Can Rely On

Every multi-state withholding decision depends on knowing where the employee actually works, and payroll systems frequently hold only a mailing address.

Capture work location as a distinct field at hire and at every change, require employees to report relocations, and reconcile periodically against expense reports or badge data where available. Employees relocate quietly and often tell HR months later, by which point the withholding has been wrong for several pay periods.

Correcting Mid-Year Errors

Where withholding has been made to the wrong state, correction generally involves stopping the incorrect withholding, beginning the correct withholding, and addressing the amounts already remitted — which may mean a refund claim from one state and a payment to another.

Employees will have questions about the effect on their personal return. Explain the mechanism clearly and, where the amounts are significant, suggest they speak to a tax preparer.

Frequently Asked Questions

Which state do we withhold for if an employee splits time between two?

Generally, tax is allocated between states based on where the work was actually performed, subject to reciprocity and each state's own sourcing rules.

Does a reciprocity agreement cover unemployment tax?

No. Reciprocity agreements address income tax withholding. Unemployment insurance sourcing is determined separately.

What if an employee moves mid-year?

Withholding should change from the date of the move, and both states may have filing obligations for the part-year period.

Related Training

Multi-state questions frequently arrive alongside workers' compensation coverage questions for the same employees — see our workers' compensation articles and workers' compensation articles guides, and the Workers' Comp 101 webinar catalog.