The key considerations from an employment law perspective in cross-border mobility are the authorization to work, taxation, and the regulation of employment. Individuals who work in the United States are required to provide current authorization in the form of a work visa. Even people working remotely in the US require work authorization. Working without it has severe consequences for individuals, including deportation and ineligibility for future permanent residency.

Taxation of earnings in the United States occurs at several levels. Individual income earned in the US is subject to federal tax plus taxation by the state where the work is performed. Only seven of the fifty states do not tax individual compensation on the state level.

Companies conducting business in the United States are required to register to do business at the federal and state levels and pay payroll and corporate taxes to federal, state and often local taxing authorities. Registering with all the various taxing authorities is a prerequisite to paying an individual for work performed in the jurisdiction. For businesses hoping to avoid the trouble by retaining workers as independent contractors, the misclassification of workers as contractors or freelancers for purposes of simplification or tax avoidance can result in significant penalties, interest and the possibility of an imposition of unpaid personal income taxes on the employer.

Employers must comply with federal employment laws and the laws of the states where employees render services. The overall level of employment regulation varies across the country and turns, to a certain degree, on cultural differences involving politics, religion, history and education. Some metropolitan areas impose added ordinances, mostly commonly with respect to minimum wages, paid sick time, leaves of absence and background screening of candidates due to perceived shortcomings in state and federal legislation.