Efail Isaf is a village in Rhondda Cynon Taf, Wales.
It is situated within the CF38 postcode district, which is within the Pontypridd post town.
The full list of postcode districts within the Pontypridd post town is as follows:
The Pontypridd post town is within the Cardiff postcode area.
Administrative Ward: Llantwit Fardre
Administrative District: Rhondda Cynon Taf
Country: Wales
UK Parliament: Pontypridd