Only amounts paid for services performed as an employee in the U.S. are includable in computing NESE. Time spent traveling to and from the U.S. is not considered as employment in the U.S., except the days of departure and arrival.

If the employee is paid a specific amount for services performed in the U.S., that amount shall be used to compute NESE.

When no specific amount is allocated for services performed partly within and partly outside the U.S., the apportionment of the employee's SEI should be on a time basis, proportionally in accordance with the time spent rendering services within and outside the U.S.