Home Postcode finder SA New Well New Well postcode SA New Well is a locality in South Australia covered by postcode 5357. Postcode 5357 State or territory South Australia (SA) Region SA Outer Suburbs Add a free New Well business listing Be the first listing in New Well Common questionsWhat is the postcode for New Well?New Well, SA has the postcode 5357.What state is New Well in?New Well is in South Australia (SA).Does postcode 5357 cover more than one suburb?Yes. Postcode 5357 covers 5 localities, so the postcode alone does not identify New Well. Browse other postcodes in South Australia, or widen the search to every Australian postcode.