Home Postcode finder QLD Blackrock Blackrock postcode QLD Blackrock is a locality in Queensland covered by postcode 4850. Postcode 4850 State or territory Queensland (QLD) Region North QLD Add a free Blackrock business listing Be the first listing in Blackrock Common questionsWhat is the postcode for Blackrock?Blackrock, QLD has the postcode 4850.What state is Blackrock in?Blackrock is in Queensland (QLD).Does postcode 4850 cover more than one suburb?Yes. Postcode 4850 covers 34 localities, so the postcode alone does not identify Blackrock. Browse other postcodes in Queensland, or widen the search to every Australian postcode.