IELTS is acceptable for Skilled Migration to Australia either in the General Training or Academic module.
OET is a test recommended for Medical and Paramedical professionals like Doctors, Dentists, Nurses etc.
Pearson Test of English [PTE]’s Academic module is acceptable for Skilled Migration from November 2014 onwards. The General Training module of this test, however, is not acceptable.
TOEFL [iBT] is also acceptable by the DIBP from November 2014 to demonstrate the English proficiency.
The duration of the above tests for an applicant applying for Skilled Migration to Australia is Three Years, as opposed to the usual Test Report Form validity of two years.