Home Postcode finder SA Australia Plains Australia Plains postcode SA Australia Plains is a locality in South Australia covered by postcode 5374. Postcode 5374 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free Australia Plains business listing Be the first listing in Australia Plains Common questionsWhat is the postcode for Australia Plains?Australia Plains, SA has the postcode 5374.What state is Australia Plains in?Australia Plains is in South Australia (SA).Does postcode 5374 cover more than one suburb?Yes. Postcode 5374 covers 15 localities, so the postcode alone does not identify Australia Plains. Browse other postcodes in South Australia, or widen the search to every Australian postcode.