Nonresidents subject to Iowa lump-sum tax or Iowa alternative minimum tax also need to file a state tax return source. Illinois residents with income from Iowa only pay tax on that income in Illinois. If passed, the Act would prevent individual states from taxing nonresidents who work in their state for less than 30 days within a calendar year:. In other words, moneu income tax laws would no longer apply to mobile workers until those workers have spent more than 30 days working in that state over the course of 12 months. In fact, 7 percent of those employees were said to have worked in four or more states for more than 30 days. Many employees will still be required to abide by state income tax laws in each state they work in, but the remaining 62 percent of mobile employees who spend less than mlney days working in another state can travel without paying additional income taxes. According to the survey, approximately 1 in 4 U. Another 1 in 3 thinks the grace period should be longer — u...