The Mobile Workforce State Income Tax Simplification Act of 2025 aims to simplify the taxation of employee income for those who work in multiple states. Its main purpose is to limit the ability of states to tax the income of employees for work done outside their home state, making it easier for employees and employers to manage tax obligations. The key provisions of this act state that employees who perform work in more than one state can only be taxed on their income by either their home state or the state where they work for more than 30 days in a year.