In Australia, some suburbs share the same postcode for efficiency in mail sorting and delivery. This practice is common in densely populated urban areas, where several nearby suburbs are grouped under one postcode to simplify the sorting process. By using a single postcode for multiple localities, postal services can streamline their operations and reduce the number of codes needed in busy areas.
Historical reasons also play a role, as some postcode boundaries were set long ago and may not have been updated to reflect changes in suburb names or boundaries by Australia Post. Additionally, postcodes for PO boxes or virtual areas often cover multiple suburbs, further consolidating postal services.