Home Postcode finder WA Mount Sheridan Mount Sheridan postcode WA Mount Sheridan is a locality in Western Australia covered by postcode 6355. Postcode 6355 State or territory Western Australia (WA) Region Wa Subs 2 Gsr Add a free Mount Sheridan business listing Be the first listing in Mount Sheridan Common questionsWhat is the postcode for Mount Sheridan?Mount Sheridan, WA has the postcode 6355.What state is Mount Sheridan in?Mount Sheridan is in Western Australia (WA).Does postcode 6355 cover more than one suburb?Yes. Postcode 6355 covers 11 localities, so the postcode alone does not identify Mount Sheridan. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.