Every worker from overseas must have a valid Australian visa with work rights. Temporary visas with work rights include working holiday maker visas, student visas and the subclass 457visa. You can check your own work and visa entitlements at Australian Immigration website
Employers are responsible for checking all workers’ rights to work in Australia and may ask to see workers’ passports or other identification. Employers must have your permission to check your work rights.
Employers cannot cancel visas. Only the Department of Immigration and Citizenship (DIAC) can grant, refuse or cancel visas. DIAC can provide information on visa choices, rights and obligations, including how to change your sponsor or apply for permanent residence.
For subclass 457 visa holders, sponsoring employers: -must give workers from overseas pay and conditions at least as good as other workers that are doing the same work at the same workplace -must only employ workers from overseas in their approved skilled occupation -must make sure that workers from overseas do not work for other employers -cannot pay workers in cash -must pay the return airfare for overseas workers if requested in writing by you or DIAC -must not make deductions from workers’ pay (other than tax) without their permission.
You do not need to use a Migration Agent to make a visa application. If you do decide to use a Migration Agent, you should make sure the agent is registered with the Office of the Migration Agents Registration Authority (MARA).