Hypobapta tachyhalotaria and H. percomptaria look very similar from the topside. MoV says H. percomptaria has been recorded on the mainland in the Snowy Mountains and H. tachyhalotaria has been recorded both in Tasmania and on the mainland. However, Bold Systems 4 shows H. percomptaria as occurring only in Tasmania.
ALA shows H. percomptaria in Qld, NSW, and Vic as well as Tas. The only useful superficial difference between the species is the colour of the underside of the hindwing, which this sighting does not record.