Home Postcode finder NSW Welby Welby postcode NSW Welby is a locality in New South Wales covered by postcode 2575. Postcode 2575 State or territory New South Wales (NSW) Region Ingleburn Add a free Welby business listing Be the first listing in Welby Common questionsWhat is the postcode for Welby?Welby, NSW has the postcode 2575.What state is Welby in?Welby is in New South Wales (NSW).Does postcode 2575 cover more than one suburb?Yes. Postcode 2575 covers 19 localities, so the postcode alone does not identify Welby. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.