Home Postcode finder WA Fimiston Fimiston postcode WA Fimiston is a locality in Western Australia covered by postcode 6432. Postcode 6432 State or territory Western Australia (WA) Region Wa Subs 1 G Flds Add a free Fimiston business listing Be the first listing in Fimiston Common questionsWhat is the postcode for Fimiston?Fimiston, WA has the postcode 6432.What state is Fimiston in?Fimiston is in Western Australia (WA).Does postcode 6432 cover more than one suburb?Yes. Postcode 6432 covers 4 localities, so the postcode alone does not identify Fimiston. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.