Home Postcodes by state SA 5418 Postcode 5418 5418 is the postcode for 2 localities in SA: Collinsville and Mount Bryan. Localities with postcode 5418CollinsvilleSAMount BryanSA Postcode 5418 State or territory South Australia (SA) Localities 2 Council area Goyder Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5417 · Postcode 5419