E-3 is a nonimmigrant visa that allows Australian citizens to come to the United States to work in a specialty occupation. Specialty occupation means theoretical and practical knowledge of a specific profession and a bachelor's degree or its equivalent. 

The spouse and dependent children under the age of 21 of the visa holder are permitted to accompany a person with an E3-D dependant's visa. The E-3 visa enables the spouse to apply for an Employment Authorization Document (EAD), which will allow them to work in the United States. Children can attend U.S schools or colleges. 

The E-3 visa holder can stay in the US for up to 2 years, but there is no limit to the number of extensions.

Requirements

Nationality

The applicants must be nationals of Australia.

Job offer

In order to get an E-3 visa, the applicants must get a valid job offer in the US.

Academic qualifications

The applicants must possess the necessary academic or other credentials to get the job.

Specialty occupation

They must prove that they will work in a job that qualifies as a specialty occupation.

Intent to depart

The applicants must demonstrate that they have an intention to depart when the E-3 visa expires. 

Period of stay

E-3 visa applicants may be permitted to the United States for a period of up to two years, which is renewable indefinitely if they can establish that they do not plan to remain or work in the United States permanently.

One E3 visa may be used several times over a person's life, and there is no limit to the number of E3 visas that can be used.