Home Postcode finder SA Custon Custon postcode SA Custon is a locality in South Australia covered by postcode 5269. Postcode 5269 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Custon business listing Be the first listing in Custon Common questionsWhat is the postcode for Custon?Custon, SA has the postcode 5269.What state is Custon in?Custon is in South Australia (SA).Does postcode 5269 cover more than one suburb?Yes. Postcode 5269 covers 3 localities, so the postcode alone does not identify Custon. Browse other postcodes in South Australia, or widen the search to every Australian postcode.