Home Postcode finder WA Mount Horner Mount Horner postcode WA Mount Horner is a locality in Western Australia covered by postcode 6525. Postcode 6525 State or territory Western Australia (WA) Region Wa Subs 4 Coast Add a free Mount Horner business listing Be the first listing in Mount Horner Common questionsWhat is the postcode for Mount Horner?Mount Horner, WA has the postcode 6525.What state is Mount Horner in?Mount Horner is in Western Australia (WA).Does postcode 6525 cover more than one suburb?Yes. Postcode 6525 covers 12 localities, so the postcode alone does not identify Mount Horner. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.