Home Postcode finder SA Mount Light Mount Light postcode SA Mount Light is a locality in South Australia covered by postcode 5271. Postcode 5271 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Mount Light business listing Be the first listing in Mount Light Common questionsWhat is the postcode for Mount Light?Mount Light, SA has the postcode 5271.What state is Mount Light in?Mount Light is in South Australia (SA).Does postcode 5271 cover more than one suburb?Yes. Postcode 5271 covers 18 localities, so the postcode alone does not identify Mount Light. Browse other postcodes in South Australia, or widen the search to every Australian postcode.