Home Postcode finder QLD Harlin Harlin postcode QLD Harlin is a locality in Queensland covered by postcode 4306. Postcode 4306 State or territory Queensland (QLD) Region Western Suburbs Add a free Harlin business listing More business listings in Harlin Businesses in HarlinHarlin State SchoolBrisbane Valley Highway · 07 54235117 Common questionsWhat is the postcode for Harlin?Harlin, QLD has the postcode 4306.What state is Harlin in?Harlin 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 Harlin. Browse other postcodes in Queensland, or widen the search to every Australian postcode.