Home Postcode finder WA Capricorn Capricorn postcode WA Capricorn is a locality in Western Australia covered by postcode 6642. Postcode 6642 State or territory Western Australia (WA) Region North West Suburbs Add a free Capricorn business listing Be the first listing in Capricorn Common questionsWhat is the postcode for Capricorn?Capricorn, WA has the postcode 6642.What state is Capricorn in?Capricorn is in Western Australia (WA).Does postcode 6642 cover more than one suburb?Yes. Postcode 6642 covers 5 localities, so the postcode alone does not identify Capricorn. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.