State tax rules for remote startup teams differ in when a home office creates employer duties, how wages are sourced, and what day-count thresholds apply. Tax nexus, the connection that lets a state tax an outside business, can arise from just one remote worker.
That single hire can force registration for withholding and unemployment tax in the worker's state. Founders must then follow each state's filing trigger, sourcing rule, and relief form. Payroll cannot use one national default.
Table of Contents
- When does one hire create a new tax duty?
- Why can two states claim the same paycheck?
- Where do you pay unemployment tax?
- What should founders track before hiring?
When does one hire create a new tax duty?
A single remote employee working from home in a new state generally creates tax nexus. BS&P CPA reports that this connection forces the startup to register there for income withholding and unemployment tax, according to BS&P guidance on remote-work nexus. California shows how fast the cost rises.
The California Franchise Tax Board subjects a foreign corporation doing business in California to franchise tax, including the $800 minimum, so one remote worker can trigger a filing obligation, described in California rules for corporations doing business in the state. Check the worker's state before the first paycheck. Register for withholding and unemployment accounts early. Late registration risks penalties, back filings, and amended W-2s.
Why can two states claim the same paycheck?
New York sources a nonresident telecommuter's pay to New York unless out-of-state duties stem from employer necessity, not employee convenience. The New York Department of Taxation and Finance sets that test in its 2024 IT-203 instructions. Five states enforce this convenience-of-employer rule: New York, Connecticut, Delaware, Nebraska and Pennsylvania.
Mosey's December 2025 review identifies those five states as taxing some nonresident remote wages as in-state work, in Mosey's review of convenience-rule states. New York offers narrow timing relief. The state tax department relieves withholding when a nonresident works 14 or fewer days in-state, but requires withholding once day 15 is worked, under TSB-M-12(5)I. The Tax Foundation warns that credits may not cure convenience-rule double tax.
Where do you pay unemployment tax?
Unemployment wages go to only one state under ordered federal tests. Forvis Mazars, summarizing Labor Department guidance UIPL 20-04, explains that employers apply localization, base of operations, direction and control, then residence, detailed in Forvis Mazars summary of multistate unemployment rules. Apply the tests in order, not by choice. Localization asks where the work happens.
If no single state fits, check base of operations, then place of direction and control, then employee residence. A coder living in one state but reporting to another still has one unemployment state. Do not split the same wages across two states. Keep offer letters, work locations, and supervision records consistent.
What should founders track before hiring?
Thresholds differ sharply by state. The Tax Foundation's January 1, 2026 survey notes New York requires nonresident filing from day one but withholding after 14 days, while many states trigger both on day one.
Reciprocity can simplify withholding between neighbors. The Illinois Department of Revenue exempts wages of Iowa, Kentucky, Michigan and Wisconsin residents, claimed with Form IL-W-5-NR to stop Illinois withholding. File Form IL-W-5-NR for an eligible nonresident before Illinois payday to prevent unneeded withholding.
- Track exact workdays by state for each employee
- Register for withholding and unemployment before payroll starts
- Collect reciprocity or exemption forms at onboarding
- Flag hires tied to convenience-rule states for review