Home Postcode finder SA Koonunga Koonunga postcode SA Koonunga is a locality in South Australia covered by postcode 5373. Postcode 5373 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free Koonunga business listing Be the first listing in Koonunga Common questionsWhat is the postcode for Koonunga?Koonunga, SA has the postcode 5373.What state is Koonunga in?Koonunga is in South Australia (SA).Does postcode 5373 cover more than one suburb?Yes. Postcode 5373 covers 8 localities, so the postcode alone does not identify Koonunga. Browse other postcodes in South Australia, or widen the search to every Australian postcode.