Home Postcode finder WA Irwin Irwin postcode WA Irwin is a locality in Western Australia covered by postcode 6525. Postcode 6525 State or territory Western Australia (WA) Region Wa Subs 4 Coast Add a free Irwin business listing Be the first listing in Irwin Common questionsWhat is the postcode for Irwin?Irwin, WA has the postcode 6525.What state is Irwin in?Irwin is in Western Australia (WA).Does postcode 6525 cover more than one suburb?Yes. Postcode 6525 covers 12 localities, so the postcode alone does not identify Irwin. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.