monjingup postcode wa Home ›› Postcode Finder ›› WA ›› Monjingup Monjingup local listingsThe suburb of Monjingup is located in WA and has a postcode of 6450. Free monjingup business listing! Get the first free listing in monjingup! Search and find other Postcodes in Western Australia or widen the search to Postcodes in Australia.