Home Postcode finder QLD Black River Black River postcode QLD Black River is a locality in Queensland covered by postcode 4818. Postcode 4818 State or territory Queensland (QLD) Region North QLD Add a free Black River business listing Be the first listing in Black River Common questionsWhat is the postcode for Black River?Black River, QLD has the postcode 4818.What state is Black River in?Black River is in Queensland (QLD).Does postcode 4818 cover more than one suburb?Yes. Postcode 4818 covers 18 localities, so the postcode alone does not identify Black River. Browse other postcodes in Queensland, or widen the search to every Australian postcode.