Home Postcode finder SA Inneston Inneston postcode SA Inneston is a locality in South Australia covered by postcode 5577. Postcode 5577 State or territory South Australia (SA) Region Sa Subs Near 1 Add a free Inneston business listing Be the first listing in Inneston Common questionsWhat is the postcode for Inneston?Inneston, SA has the postcode 5577.What state is Inneston in?Inneston is in South Australia (SA).Does postcode 5577 cover more than one suburb?Yes. Postcode 5577 covers 3 localities, so the postcode alone does not identify Inneston. Browse other postcodes in South Australia, or widen the search to every Australian postcode.