Home Postcode finder WA Boulder Boulder postcode WA Boulder 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 Boulder business listing More business listings in Boulder Businesses in BoulderBoulder Primary SchoolLane St · 08 90931295Kalgoorlie School of the AirCnr Piesse & Brookman Sts · 08 90932728O'Connor Education Support CentreJohnston St · 08 90919114 Common questionsWhat is the postcode for Boulder?Boulder, WA has the postcode 6432.What state is Boulder in?Boulder 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 Boulder. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.