Compliance

Multi-State Payroll Compliance Guide for US SMBs (2026)

The moment your business hires its first out-of-state employee, payroll gets exponentially harder. State income tax, unemployment insurance, workers' comp, local taxes, and reciprocity agreements all change overnight. Here's what every US SMB needs to know in 2026.

The five things multi-state payroll touches

1. State income tax (SIT). Withhold based on where the employee works, not where your office is.
2. State unemployment insurance (SUI). Pay UI premiums to the state where the employee performs work.
3. Workers' compensation. Coverage required in every state where you have employees.
4. Local taxes. 17 states allow local income taxes (PA, OH, NY, MD, etc.). Easy to miss.
5. Nexus. Hiring an employee in a state typically creates corporate income tax nexus there too.

Reciprocity agreements (the good news)

Many states have reciprocity — your employee can live in one state and work in another while only paying SIT in one. Common pairs: NJ–PA, NY–NJ partial, IL–IA, DC–MD, VA. If your employee qualifies, file the right reciprocity form (e.g., Form REV-419 for PA) and you only withhold for the home state.

Remote workers (the tricky part)

Post-pandemic, the IRS and most states agreed that where the employee physically performs work determines tax obligations, not where the company is headquartered. If you have a remote employee in Florida and your HQ is in California, you owe Florida SUI and workers' comp, even though Florida has no SIT.

States with no income tax (8 states)

If your remote employee is in Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, or Wyoming, you skip SIT withholding. But you still owe SUI, workers' comp, and any local taxes.

The compliance checklist for each new state

• Register for state employer ID (typically free, takes 1–2 weeks)
• Register for state unemployment tax account
• Get a workers' comp policy that covers the state
• Add the state to your payroll provider's tax engine
• Set up state tax forms in your hiring paperwork (state W-4 equivalent)
• Check for local taxes (city, county, school district)
• Note quarterly filing deadlines — they vary

Common mistakes that trigger audits

• Withholding for the wrong state when an employee moves
• Missing quarterly SUI deadlines (penalties compound)
• Ignoring local taxes in PA, OH, NY metros
• Misclassifying remote contractors as W-2 employees (or vice versa)
• Not updating workers' comp when an employee relocates

How MyCo handles this

MyCo's payroll engine knows the rules for all 50 states out of the box. When you add an employee, we ask one question: where do they physically work? Everything else — SIT, SUI, local taxes, workers' comp deductions, year-end filings — is auto-configured.

For SMBs growing across state lines for the first time, this is the single biggest reason customers switch from Gusto, ADP Run, or QuickBooks Payroll to MyCo.

What to do this quarter

1. Audit your team list — confirm physical work location for every employee
2. Cross-check your payroll system's tax setup against that list
3. Verify SUI registrations exist for every state on the list
4. Check your workers' comp policy covers every state on the list

If you find gaps, book a 20-min MyCo demo and we'll show you how to fix them in a week, not a quarter.