One of the most popular topics for the ABC's You Ask, We Answer project has been early voting — an increasingly popular choice for Australians.

Can I vote early if I have terminal cancer?

For people who are seriously ill — no matter the prognosis — the short answer is yes, you can cast your ballot before Saturday, May 18, at an early voting centre using a postal vote, on the phone or at a mobile polling place, depending on your circumstances.

"The Australian Electoral Commission (AEC) does undertake an extensive program of mobile polling of various aged care, nursing homes and hospitals between now and the day before election day," a spokesperson said.

This was supported by Palliative Care South Australia, which said polling officials visit hospices in the lead-up to state and federal elections.

For people who need extra assistance due to a disability or other mobility issues, the AEC said staff at voting centres were trained to help people vote.

It can even arrange for ballot papers to be brought out to a car if the polling official in charge is satisfied the person cannot make it in.

I have a terminal illness. Do I need to vote?

Again, the short answer is yes, but this one is a little complicated.

Tony Lawson, the chief executive of Palliative Care SA, said voting was a person's democratic right but a person with a terminal illness may not be willing.

"I would be really concerned if people were heavying people to vote if they don't want to or are unable to, given their circumstances," Mr Lawson said.

"It would depend if people were really unwell — they may take the attitude that there's no point.

"Others would believe it's important to vote on policies affecting their health outcomes."

Cases where people cannot provide a "valid and sufficient reason" to vote can end up in court.

"The AEC does not provide a list of excuses to not attend voting," a spokesperson said.

The commission has published a backgrounder on compulsory voting in Australia, as well as laws enforcing this and some legal challenges.

A penalty notice will not be sent to someone who appears to have failed to vote when they have in fact died.

The penalty is a $20 fine.