To limit the authority of States and localities to tax certain income of employees for employment duties performed in other States and localities.

Summary: Mobile Workforce State Income Tax Fairness and Simplification Act of 2007- Limits state or local taxation of the compensation of any employee who performs duties in more than one state or locality to: (1) the state or locality of the employee's residence; and (2) the state or locality in which the employee is physically present performing duties for more than 60 days.

SECTION 1. SHORT TITLE.

    This Act may be cited as the ``Mobile Workforce State Income Tax 
Fairness and Simplification Act of 2007''.

SEC. 2. LIMITATIONS ON STATE AND LOCALITY WITHHOLDING AND TAXATION OF 
              EMPLOYEE INCOME.

    (a) In General.--No part of the wages or other remuneration paid to 
an employee who performs duties in more than one State or locality 
shall be subject to the income tax laws of any State or locality other 
than--
            (1) the State or locality of the employee's residence; and
            (2) the State or locality in which the employee is 
        physically present performing duties for more than 60 days 
        during the calendar year in which the income is taxed.
    (b) Wages or Other Remuneration.--Wages or other remuneration paid 
in any calendar year are not subject to State or locality income tax 
withholding and reporting unless the employee is subject to income tax 
under subsection (a). Income tax withholding and reporting under 
subsection (a)(2) shall apply to wages or other remuneration paid as of 
the commencement date of duties in the State or locality during the 
calendar year.
    (c) Operating Rules.--For purposes of determining an employer's 
State income tax withholding and information return obligations--
            (1) an employer may rely on an employee's determination of 
        the time expected to be spent by such employee in the States or 
        localities in which the employee will perform duties absent--
                    (A) actual knowledge of fraud by the employee in 
                making the estimate; or
                    (B) collusion between the employer and the employee 
                to evade tax;
            (2) if records are maintained by an employer recording the 
        location of an employee for other business purposes, such 
        records shall not preclude an employer's ability to rely on an 
        employee's determination as set forth in paragraph (1); and
            (3) notwithstanding paragraph (2), if an employer, at its 
        sole discretion, maintains a time and attendance system which 
        tracks where the employee performs duties on a daily basis, 
        data from the time and attendance system shall be used instead 
        of the employee's determination as set forth in paragraph (1).
    (d) Definitions and Special Rules.--For purposes of this Act:
            (1) Day.--An employee will be considered physically present 
        and performing duties in a State or locality for a day if the 
        employee performs more than 50 percent of the employee's 
        employment duties in such State or locality for such day.
            (2) Employee.--The term ``employee'' shall be defined by 
        the State or locality in which the duties are performed, except 
        that the term ``employee'' shall not include a professional 
        athlete, professional entertainer, or certain public figures.
            (3) Professional athlete.--The term ``professional 
        athlete'' means a person who performs services in a 
        professional athletic event, provided that the wages or other 
        remuneration are paid to such person for performing services in 
        his or her capacity as a professional athlete.
            (4) Professional entertainer.--The term ``professional 
        entertainer'' means a person who performs services in the 
        professional performing arts, provided that the wages or other 
        remuneration are paid to such person for performing services in 
        his or her capacity as a professional entertainer.
            (5) Certain public figures.--The term ``certain public 
        figures'' means persons of national prominence who perform 
        services for wages or other remuneration on a per-event basis, 
        provided that the wages or other remuneration are paid to such 
        person for services provided at a discrete event in the form of 
        a speech, similar presentation or personal appearance.
            (6) Employer.--The term ``employer'' has the meaning given 
        such term in section 3401(d) of the Internal Revenue Code of 
        1986 (26 U.S.C. 3401(d)) or shall be defined by the State or 
        locality in which the duties are performed.
            (7) Locality.--The term ``locality'' means any political 
        subdivision, agency, or instrumentality of a State.
            (8) State.--The term ``State'' means each of the several 
        States (or any subdivision thereof), or any territory or 
        possession of the United States.
            (9) Time and attendance system.--The term ``time and 
        attendance system'' means a system where the employee on a 
        contemporaneous basis records his work location for every day 
        worked and the employer uses this data to allocate the 
        employee's wages between all taxing jurisdictions in which the 
        employee performs duties.
            (10) Wages or other remuneration.--The term ``wages or 
        other remuneration'' shall be defined by the State or locality 
        in which the employment duties are performed.