Home Postcode finder QLD Blackdown Blackdown postcode QLD Blackdown is a locality in Queensland covered by postcode 4702. Postcode 4702 State or territory Queensland (QLD) Region Central QLD Add a free Blackdown business listing Be the first listing in Blackdown Common questionsWhat is the postcode for Blackdown?Blackdown, QLD has the postcode 4702.What state is Blackdown in?Blackdown is in Queensland (QLD).Does postcode 4702 cover more than one suburb?Yes. Postcode 4702 covers 87 localities, so the postcode alone does not identify Blackdown. Browse other postcodes in Queensland, or widen the search to every Australian postcode.