In Australia, voting in a referendum is compulsory. If you do not vote in a referendum, you may receive a fine. The process for dealing with non-voters is as follows:

1. Apparent failure to vote notice (First notice): This notice is sent within 90 days following the election. It gives you the opportunity to explain why you didn’t vote, or if in fact, you did vote. It is an offence not to respond to this notice. If your reason is accepted there is no further action. Your response must be received by the date indicated on the notice.

2. Expiation notice $104 (Second notice): You will receive an expiation notice if you do not respond to the apparent failure to vote notice, or if you don’t provide a valid and sufficient reason for not voting. The expiration notice is issued under the Expiation of Offences Act. The expiation amount is a $10 expiation fee for the offence and a $94 victims of crime levy. Your options in dealing with the expiation notice are set out in the Expiation of Offences Act and are included on the reverse side of the expiation notice.

It is important to note that failing to vote in a referendum will not count as a "Yes" vote.