Home Postcode finder SA Ob Flat Ob Flat postcode SA Ob Flat is a locality in South Australia covered by postcode 5291. Postcode 5291 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Ob Flat business listing Be the first listing in Ob Flat Common questionsWhat is the postcode for Ob Flat?Ob Flat, SA has the postcode 5291.What state is Ob Flat in?Ob Flat is in South Australia (SA).Does postcode 5291 cover more than one suburb?Yes. Postcode 5291 covers 34 localities, so the postcode alone does not identify Ob Flat. Browse other postcodes in South Australia, or widen the search to every Australian postcode.