Home Postcode finder QLD South Mackay South Mackay postcode QLD South Mackay is a locality in Queensland covered by postcode 4740. Postcode 4740 State or territory Queensland (QLD) Region Central QLD Add a free South Mackay business listing Be the first listing in South Mackay Common questionsWhat is the postcode for South Mackay?South Mackay, QLD has the postcode 4740.What state is South Mackay in?South Mackay is in Queensland (QLD).Does postcode 4740 cover more than one suburb?Yes. Postcode 4740 covers 50 localities, so the postcode alone does not identify South Mackay. Browse other postcodes in Queensland, or widen the search to every Australian postcode.