gumma postcode nswst Home ›› Postcode Finder ›› NSWST ›› Gumma Gumma local listingsThe suburb of Gumma is located in NSW and has a postcode of 2447. Free gumma business listing! Get the first free listing in gumma! Search and find other Postcodes in New South Wales or widen the search to Postcodes in Australia.