Home Postcode finder QLD Causeway Lake Causeway Lake postcode QLD Causeway Lake is a locality in Queensland covered by postcode 4703. Postcode 4703 State or territory Queensland (QLD) Region Central QLD Add a free Causeway Lake business listing Be the first listing in Causeway Lake Common questionsWhat is the postcode for Causeway Lake?Causeway Lake, QLD has the postcode 4703.What state is Causeway Lake in?Causeway Lake is in Queensland (QLD).Does postcode 4703 cover more than one suburb?Yes. Postcode 4703 covers 30 localities, so the postcode alone does not identify Causeway Lake. Browse other postcodes in Queensland, or widen the search to every Australian postcode.