Overview

As more employees work from a state different than their employer’s home office, employers must confirm where wages are taxable and where payroll taxes must be registered and withheld. States use different tests — residency, source-of-income, day-counts, and in a few cases a “convenience of the employer” rule — to determine taxability. Get into the habit of checking the state department of revenue for the definitive rule that applies to each employee.

Key employer responsibilities (practical checklist)

  1. Determine the employee’s primary work location(s).
  • Capture the employee’s physical work address(es) and any regular travel pattern. Track days worked in each state — many states use day-counts to source wages.
  1. Check residency and source rules for the states involved.
  • Some states tax residents on worldwide income; others tax nonresidents only on income sourced to the state. A few states (notably New York) apply a “convenience of the employer” test that can cause nonresidents’ remote wages to be taxable to the employer’s state. Consult the relevant state DOR and NCSL guidance on remote worker tax treatment.
  1. Register your business for withholding (and SUTA) where required.
  • If state rules require withholding or employer payroll tax registration, register promptly. Late registration can result in penalties and interest.
  1. Withhold the correct state income tax (or withhold none if the state has no income tax).
  • Use the employee’s work-state rules and any applicable reciprocal agreements. Some states have reciprocity that allows withholding based on the employee’s residence instead of the work state.
  1. Update payroll systems and tax tables.
  • Configure payroll so withholding calculations, state tax IDs, and wage-sourcing logic match each employee’s work pattern. Use payroll vendors that support multi-state withholding.
  1. Track and document employee location and policy elections.
  • Maintain contemporaneous records (work-location forms, time logs, expense reimbursements) to support withholding decisions in case of audit.
  1. Prepare correct reporting and year-end forms.
  • File state withholding returns and issue W-2s showing state wages and taxes withheld for each applicable state.
  1. Monitor nexus and broader tax exposure.
  • Remote employees can create nexus for income, sales, and unemployment insurance. Coordinate with payroll and legal teams to understand business-level implications.
  1. Communicate policies to employees.
  • Publish remote-work tax guidance, ask employees to report moves immediately, and require completion of location-attestation forms.

Common compliance traps

  • Assuming employer location dictates withholding. Withholding is often based on where the employee performs the work or on residency, not where the employer is headquartered.
  • Failing to track telecommute days. When an employee splits time across states, incorrect sourcing can lead to underwithholding and penalties.
  • Relying on employee statements alone. Employers remain liable for correct withholding even if the employee misstates their location.
  • Missing non-income obligations. Remote workers can create SUTA and other payroll obligations in the work state.

Real-world examples (concise)

  • Reciprocal agreement: If State A and State B have reciprocity, an employee who lives in State A but works in State B may elect withholding based on residency. Employers must still obtain the required reciprocity form and withhold accordingly.
  • Multi-state split: An employee who spends 80% of workdays in State X and 20% in State Y may have wages allocated by day-counts; payroll must withhold to each state per their rules.

Penalties and risk

Failure to register and withhold correctly can trigger state penalties, interest, and liability for unpaid withholding. Employers can be held responsible even when the employee relocated without notifying the company. Prompt correction and voluntary disclosure programs in many states can reduce penalties; consult state guidance early.

Practical tips for employers (professional experience)

  • Build a short remote-work tax policy that requires employees to certify their work location and report moves within 30 days.
  • Use payroll providers or software with multi-state withholding logic; test scenarios for split-state work.
  • Conduct an annual review of states where employees perform work and confirm registration status.
  • When in doubt, contact the state department of revenue or a multistate payroll tax advisor — early guidance can prevent costly retroactive liabilities.

Related FinHelp resources

Authoritative sources and further reading

  • IRS — Employer’s Tax Guide (Publication 15): https://www.irs.gov/publications/p15
  • National Conference of State Legislatures — state approaches to remote-worker taxation: https://www.ncsl.org/
  • State department of revenue websites — search the DOR for each relevant state for exact withholding and reciprocity forms.

Professional disclaimer

This article is educational and not a substitute for individualized tax advice. State withholding and nexus rules change frequently; consult a licensed tax advisor or the applicable state revenue agency for guidance tailored to your situation.