The Timorese horseshoe bat was described from cave records on Timor. Goodwin's 1979 paper treated it as a subspecies; a later type-specimen review found differences beyond variation within its former species.
Compared with the related R. philippinensis, the sella and connecting process of the noseleaf differ in shape, and the nasal swellings are more pronounced. The external noseleaf form is intermediate between two related species.
In the Quoto Lou Caves on Timor, the horseshoe bats studied hung from low ceilings and rested in small, widely spaced groups. Goodwin estimated about six to seven R. p. montanus there.
An extinction-risk assessment has not been added yet.