Click on a company name for more information on that company
| Irish Company Name | Partial Irish Company Address |
| 1, 2 And 2a Castle Street Development (Dalkey) Owners Management Company Limited By Guarantee | Dalkey, Dublin |
| 12 Arch Machinery Limited | Ballydehob, Cork, Ireland |
| 12 Camden Street Owners' Management Company Limited By Guarantee | Dublin 2 |
| 12 Hour Laundry Limited | Dublin 16, Dublin |
| 12 Quail Farm Soap Studio Limited | Foxfield, Fenagh Co Leitrim, Fenagh, Leitrim |
| 12 Tables Eastside Limited | Douglas, Cork, Ireland |
| 120/121 Lower Baggot St Propco Limited | Blackrock, Dublin, Ireland |
| 121 Digital Revolution Company Limited By Guarantee | Station House, Shankill, Dublin, Ireland |
| 121 French Tuition Limited | Barna, Galway, Ireland |
| 121 Remote Captions Limited | Dundrum Road, Dundrum, Dublin 14, Ireland |
| 121 Safety Limited | Coole, Westmeath, Ireland |
| 1215 Counterpoint Productions Limited | Ladytown Business Park, Newhall, Naas, Kildare |
| 122 Lower Baggot Street Propco Limited | Blackrock, Dublin, Ireland |
| 123 Money Limited | Dundrum Town Centre, Sandyford Road, Dublin 16, Dublin, Ireland |
| 123 O'Connell Accountants Limited | Newbridge, Kildare |
| 126 Artist-Run Gallery & Studios Company Limited By Guarantee | Galway, Galway |
| 1297 Renovation Projects Limited | Off Lapps Quay, , Ireland |
| 12foot Insight Limited | Coolgarrow, Avoca, Arklow, Wicklow, Ireland |
| 12th Lock Creative Industries Limited | St. Stephen'S Green, Dublin 2 |