Home Postcodes by state SA 5550 Postcode 5550 5550 is the postcode for 8 localities in SA: Beaufort, Bowmans, Inkerman, Kallora, Nantawarra, Port Wakefield and 2 more. Localities with postcode 5550BeaufortSABowmansSAInkermanSAKalloraSANantawarraSAPort WakefieldSAProof RangeSASouth HummocksSA Postcode 5550 State or territory South Australia (SA) Localities 8 Council area Wakefield; Mainly Barunga West, partly Wakefield Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5540 · Postcode 5552