Home Postcode finder SA Hallett Hallett postcode SA Hallett is a locality in South Australia covered by postcode 5419. Postcode 5419 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Hallett business listing Be the first listing in Hallett Common questionsWhat is the postcode for Hallett?Hallett, SA has the postcode 5419.What state is Hallett in?Hallett is in South Australia (SA).Does postcode 5419 cover more than one suburb?Yes. Postcode 5419 covers 7 localities, so the postcode alone does not identify Hallett. Browse other postcodes in South Australia, or widen the search to every Australian postcode.