Llanllwchaiarn is a village in Powys, Wales.
It is situated within the SY16 postcode district, which is within the Newtown post town.
SY16 is the only postcode district within the Newtown post town.
The Newtown post town is within the Shrewsbury postcode area.
Administrative Ward: Newtown Llanllwchaiarn West
Administrative District: Powys
Country: Wales
UK Parliament: Montgomeryshire