Mobile Work Tax Overhaul Proposed: Pay State Income Tax Only After 30 Days On-Site Under New Bill

Crossing State Lines? The New 30-Day Tax Rule

Here's the deal: the Mobile Workforce State Income Tax Simplification Act of 2025 aims to change how states tax you if your job has you working across state lines. The core idea is pretty straightforward: under this bill, you'd generally only owe income tax to your home state and any other state where you physically work for more than 30 days in a calendar year. If you spend less than 31 days working in a state you don't live in, that state generally couldn't tax your income.

This also changes things for employers. They would only be required to handle income tax withholding and reporting for the states where you actually meet that 30-day threshold. The bill defines a 'day' of work in a state as performing more duties there than in any other state that day. There's a specific rule too: if you work in your home state and just one other state on the same day, you're counted as working in the other (non-resident) state for that day. Time spent just traveling doesn't count.

Tracking Time & Who's Exempt: The Fine Print

So, how does your boss know where you are? The bill gives employers some leeway. They can generally rely on your good-faith estimate of where you expect to work and for how long. However, there are catches. If your employer knows you're providing false information (though 'knows' isn't defined), they can't use your estimate. More importantly, if your company uses a formal "time and attendance system" that tracks your work location daily (think badge swipes or specific software), that system's data must be used instead of your estimate.

It's also crucial to know who isn't covered by this simplification. The bill specifically excludes professional athletes, professional entertainers (think prominent figures paid per event), certain film/TV production employees working under state incentive programs, and other 'certain public figures' paid per event. These groups often have complex, existing state tax rules that wouldn't change under this act. For everyone else defined as an 'employee' under state law, these new rules would apply.

Untangling the Tax Web: What This Means

For anyone who's ever wrestled with multiple state tax forms after short work trips, this bill could significantly simplify things. It aims to reduce the administrative headache for both employees and employers dealing with temporary work assignments in different states. The idea is to create a clearer, more uniform standard, replacing the patchwork of different state rules that currently exists.

However, the shift isn't without potential wrinkles. States that currently collect significant income tax from short-term, non-resident workers might see a revenue dip. There's also the practical challenge of accurately tracking workdays, especially with the specific definition of a 'day' and the reliance on different tracking methods. If enacted, these changes would kick in on January 1st of the second calendar year after the bill becomes law, applying only to tax obligations from that date forward.