Australian Amateurs who allow their licence to lapse can have a journey to renew their callsign.
Holders of expired licences have to contact the WIA who need to issue a recommendation for a new licence application. One of the main reasons many Australian Amateurs suffer this process is because the Australian Radiocommunications Act does not have a requirement to advise licence holders of the renewal date.
Whilst the ACMA does its best to fill this void, in many instances, a renewal notice is not received.
An Australian amateur radio callsign is only a condition of a licence, and if the licence is not renewed, after 60 days the callsign will be put on the WIA Public List on its website. After 7 days the WIA will issue a Callsign Recommendation to whoever wants it, with ballot provisions applying to 2-letter callsign in some states.
More information - http://www.wia.org.au