Home Postcodes by state VIC 3688 Postcode 3688 3688 is the postcode for 2 localities in VIC: Barnawartha and Indigo Valley. Localities with postcode 3688BarnawarthaVICIndigo ValleyVIC Postcode 3688 State or territory Victoria (VIC) Localities 2 Council area Indigo Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 3687 · Postcode 3690