- Y Felinheli - 1 company
- Yarmouth - 2 companies
- Yate - 9 companies
- Yate Rocks - 1 company
- Yateley - 11 companies
- Yaxley - 3 companies
- Yeadon - 2 companies
- Yelverton - 7 companies
- Yeovil - 51 companies
- York - 212 companies
- Yorkshire - 7 companies
- Ystrad Mynach - 2 companies
- Ystradgynlais - 1 company