Home Postcodes by state SA 5261 Postcode 5261 5261 is the postcode for 5 localities in SA: Cooke Plains, Coomandook, Culburra, Ki Ki and Yumali. Localities with postcode 5261Cooke PlainsSACoomandookSACulburraSAKi KiSAYumaliSA Postcode 5261 State or territory South Australia (SA) Localities 5 Council area Coorong Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5260 · Postcode 5262