Home Postcodes by state SA 5521 Postcode 5521 5521 is the postcode for Redhill, SA. Localities with postcode 5521RedhillSA Postcode 5521 State or territory South Australia (SA) Localities 1 Council area Port Pirie Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5520 · Postcode 5522