hardwicke-bay postcode sa Home ›› Postcode Finder ›› SA ›› Hardwicke-Bay Hardwicke Bay local listingsThe suburb of Hardwicke Bay is located in SA and has a postcode of 5575. Free hardwicke bay business listing! Get the first free listing in hardwicke bay! Search and find other Postcodes in South Australia or widen the search to Postcodes in Australia.