Home Postcode finder WA Warralakin Warralakin postcode WA Warralakin is a locality in Western Australia covered by postcode 6421. Postcode 6421 State or territory Western Australia (WA) Region Wa Subs 1 G Flds Add a free Warralakin business listing Be the first listing in Warralakin Common questionsWhat is the postcode for Warralakin?Warralakin, WA has the postcode 6421.What state is Warralakin in?Warralakin is in Western Australia (WA).Does postcode 6421 cover more than one suburb?Yes. Postcode 6421 covers 3 localities, so the postcode alone does not identify Warralakin. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.