Home Postcode finder SA Hardy Hardy postcode SA Hardy is a locality in South Australia covered by postcode 5422. Postcode 5422 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Hardy business listing Be the first listing in Hardy Common questionsWhat is the postcode for Hardy?Hardy, SA has the postcode 5422.What state is Hardy in?Hardy is in South Australia (SA).Does postcode 5422 cover more than one suburb?Yes. Postcode 5422 covers 13 localities, so the postcode alone does not identify Hardy. Browse other postcodes in South Australia, or widen the search to every Australian postcode.