Home Postcode finder SA Denial Bay Denial Bay postcode SA Denial Bay is a locality in South Australia covered by postcode 5690. Postcode 5690 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Denial Bay business listing Be the first listing in Denial Bay Common questionsWhat is the postcode for Denial Bay?Denial Bay, SA has the postcode 5690.What state is Denial Bay in?Denial Bay is in South Australia (SA).Does postcode 5690 cover more than one suburb?Yes. Postcode 5690 covers 19 localities, so the postcode alone does not identify Denial Bay. Browse other postcodes in South Australia, or widen the search to every Australian postcode.