Home Postcode finder QLD Welsby Welsby postcode QLD Welsby is a locality in Queensland covered by postcode 4507. Postcode 4507 State or territory Queensland (QLD) Region Moreton Add a free Welsby business listing Be the first listing in Welsby Common questionsWhat is the postcode for Welsby?Welsby, QLD has the postcode 4507.What state is Welsby in?Welsby is in Queensland (QLD).Does postcode 4507 cover more than one suburb?Yes. Postcode 4507 covers 8 localities, so the postcode alone does not identify Welsby. Browse other postcodes in Queensland, or widen the search to every Australian postcode.