1. Short title This Act may be cited as the Mobile Workforce State Income Tax Simplification Act of 2017 . 2. Limitations on State withholding and taxation of employee income (a) In general No part of the wages or other remuneration earned by an employee who performs employment duties in more than one State shall be subject to income tax in any State other than— (1) the State of the employee’s residence; and (2) the State within which the employee is present and performing employment duties for more than 30 days during the calendar year in which the wages or other remuneration is earned. (b) Wages or other remuneration Wages or other remuneration earned in any calendar year shall not be subject to State income tax withholding and reporting requirements unless the employee is subject to income tax in such State under subsection (a). Income tax withholding and reporting requirements under subsection (a)(2) shall apply to wages or other remuneration earned as of the commencement date of employment duties in the State during the calendar year. (c) Operating rules For purposes of determining penalties related to an employer’s State income tax withholding and reporting requirements— (1) an employer may rely on an employee’s annual determination of the time expected to be spent by such employee in the States in which the employee will perform duties absent— (A) the employer’s actual knowledge of fraud by the employee in making the determination; or (B) collusion between the employer and the employee to evade tax; (2) except as provided in paragraph (3), if records are maintained by an employer in the regular course of business that record the location of an employee, such records shall not preclude an employer’s ability to rely on an employee’s determination under paragraph (1)