Businesses that function both in the United States and in their home country gain the benefits of the best of both areas. The L-1 visa is open to international organizations with offices in the U.S., and who transfer employees to the U.S. office for temporary periods of time. This visa is sometimes referred to as the 'intra-company transferee' visa. To obtain an L-1 visa, an employee must have worked for a non-U.S. company for at least one full year within the last three years as an executive, manager or employee with specialized knowledge. The L-1 visa enables the transfer of managers, executives and specialized knowledge personnel to a U.S. office, parent, subsidiary or affiliated company. L-1A visas are for executives and managers whereas L-1B visas are for personnel with specialized knowledge.  The spouse and unmarried children under the age of 21 of an L-1 visa holder are allowed to accompany the employee in the U.S. in L-2 status.  Unlike spouses who accompany beneficiaries of several other kinds of employment-based visas, those in L-2 status are permitted to work in the U.S.  They may also attend school or college. Servants of individuals coming to the United States in L-1 status may also be eligible for a B-1 visa with work authorization.