gum-flat postcode nswst Home ›› Postcode Finder ›› NSWST ›› Gum-Flat Gum Flat local listingsThe suburb of Gum Flat is located in NSW and has a postcode of 2360. Free gum flat business listing! Get the first free listing in gum flat! Search and find other Postcodes in New South Wales or widen the search to Postcodes in Australia.