When does a Member who does not recontest their seat at the next election effectively retire? Is it at the dissolution of the House?
Thanks for your question.
Yes, you’re right! A member of the House of Representatives who does not recontest – seek re-election – a federal election ceases to be a member from the date of the dissolution of the House. Dissolution refers to the act of closing the House of Representatives prior to calling a federal election.
Casting a vote for the House of Representatives

Australian Electoral Commission
Description
A voter is casting a vote in a federal election. They are placing their green House of Representatives ballot paper into the ballot box labelled 'House of Representatives'. Senate ballot papers are white and are placed into the other ballot box, labelled 'Senate'.
Permission should be sought from the Australian Electoral Commission (AEC) for third-party or commercial uses of this image. To contact the AEC email: media@aec.gov.au or phone: 13 23 26.