Home Postcodes by state VIC 3400 Postcode 3400 3400 is the postcode for 2 localities in VIC: Horsham and Horsham West. Localities with postcode 3400HorshamVICHorsham WestVIC Postcode 3400 State or territory Victoria (VIC) Localities 2 Council area Horsham Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 3396 · Postcode 3401