It is possible to request a medical certificate online in Australia. Telehealth doctors need to be  fully registered with AHPRA .These days it is quite common for Australian GPs and specialists to assess their patients via video consultation, for all sorts of health issues. You should expect the doctor to ask you some questions about your medical history and your symptoms, just as they would in a regular clinic. A medical certificate can relate to a previous day or days, subject to assessment, and provided the period of sick leave is very recent, e.g. within the past few days. However the date of the consultation always appears at the top of the certificate, with the relevant dates of sick leave stated in the certificate also.

A medical certificate issued via an appropriately conducted online assessment is a legal document, just the same as one you’d receive in a clinic. For more information on your rights as an employee go to www.fairwork.gov.au .   

It is also important to note that an online doctor may occasionally advise you to see a doctor in person instead, for example, if they assess that you are more significantly unwell and a physical examination is needed.