Employment by the U.S. employer cannot begin until the H-1B visa is approved unless the alien already has H-1B visa status. In that case, employment can begin as soon as the new H-1B visa application is filed. However, if an individual possesses previous employment authorization such as a work authorization card, employment may be authorized up until the point that the H-1B visa is approved. If an individual already has an H-1B visa for the specific employer who is seeking to continue the employment, employment authorization is continued by the filing of the H-1B petition seeking to extend the employment and it is not necessary that the petition be actually approved.