Undy is a village in Monmouthshire, Wales.
It is situated within the NP26 postcode district, which is within the Caldicot post town.
NP26 is the only postcode district within the Caldicot post town.
The Caldicot post town is within the Newport postcode area.
Administrative Ward: The Elms
Administrative District: Monmouthshire
Country: Wales
UK Parliament: Newport East