Home Postcode finder SA Merghiny Merghiny postcode SA Merghiny is a locality in South Australia covered by postcode 5690. Postcode 5690 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Merghiny business listing Be the first listing in Merghiny Common questionsWhat is the postcode for Merghiny?Merghiny, SA has the postcode 5690.What state is Merghiny in?Merghiny is in South Australia (SA).Does postcode 5690 cover more than one suburb?Yes. Postcode 5690 covers 19 localities, so the postcode alone does not identify Merghiny. Browse other postcodes in South Australia, or widen the search to every Australian postcode.