The Red-brown Pipistrelle has records from Kalimantan and Sabah. The 2016 IUCN assessment presumes forest habitat and notes it may be the same species as H. lophurus.
The 1915 original description says its dorsal fur is darker, richer brown than P. imbricatus, while the underside is lighter; the wings are smoky gray.
The 2016 IUCN assessment presumes lowland and montane forest as habitat and says little is known about the species’ wild ecology.
An extinction-risk assessment has not been added yet.