ID is not required to vote in Australia, and voting is compulsory (this is a very good thing). Your name and address are listed on the electoral roll, and the polling place staff cross your name off on their sheet (or nowadays on a computer) when you collect your ballot papers. After the votes are counted they compare the rolls and if your name is crossed off multiple times or not at all, you get a “please explain” letter. If you don’t have a good excuse then you get a fine. The fine for not voting is pretty small, it’s more about getting people to vote by triggering loss aversion rather than actual punishment. Actual voting fraud could be more serious depending on the specifics of the case.