Home Postcode finder QLD Ironbark Ironbark postcode QLD Ironbark is a locality in Queensland covered by postcode 4306. Postcode 4306 State or territory Queensland (QLD) Region Western Suburbs Add a free Ironbark business listing Be the first listing in Ironbark Common questionsWhat is the postcode for Ironbark?Ironbark, QLD has the postcode 4306.What state is Ironbark in?Ironbark is in Queensland (QLD).Does postcode 4306 cover more than one suburb?Yes. Postcode 4306 covers 56 localities, so the postcode alone does not identify Ironbark. Browse other postcodes in Queensland, or widen the search to every Australian postcode.