Home Postcode finder WA Lake Biddy Lake Biddy postcode WA Lake Biddy 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 Lake Biddy business listing Be the first listing in Lake Biddy Common questionsWhat is the postcode for Lake Biddy?Lake Biddy, WA has the postcode 6355.What state is Lake Biddy in?Lake Biddy 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 Lake Biddy. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.