Home Postcode finder SA Undalya Undalya postcode SA Undalya is a locality in South Australia covered by postcode 5451. Postcode 5451 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free Undalya business listing Be the first listing in Undalya Common questionsWhat is the postcode for Undalya?Undalya, SA has the postcode 5451.What state is Undalya in?Undalya is in South Australia (SA).Does postcode 5451 cover more than one suburb?Yes. Postcode 5451 covers 2 localities, so the postcode alone does not identify Undalya. Browse other postcodes in South Australia, or widen the search to every Australian postcode.