| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| ABERSOCH BAY LIMITED | 07724028 | 01/08/2011 | Dissolved |
| BRO MÔN | 12457104 | 11/02/2020 | Not Trading |
| Buoywork (Anglesey) Ltd | 01148912 | 15/03/1999 | Dissolved |
| FLEXBRUSH LIMITED | 01952388 | 09/12/2002 | Dissolved |
| FLEXBRUSH LIMITED | 01952388 | 09/12/2002 | Dissolved |
| HOLYHEAD MARINE SERVICES LIMITED | 00895484 | 15/03/1999 | Gold |
| HOLYHEAD MARINE SERVICES LIMITED | 00895484 | 25/04/2000 | Gold |
| HOLYHEAD TRANSPORTATION COMPANY LIMITED | 04682934 | 25/04/2003 | Dissolved |
| HOLYHEAD TRANSPORTATION COMPANY LIMITED | 04682934 | 25/04/2003 | Dissolved |
| HOLYHEAD WORKBOATS LIMITED | 07341750 | 10/08/2010 | Dissolved |
| Holyhead Shipping Agency Ltd | 00789913 | 15/03/1999 | Dissolved |
| Holyhead Shipping Agency Ltd | 00789913 | 25/04/2000 | Dissolved |
| Penrhos Plant Hire Ltd | 01499563 | 15/03/1999 | Dissolved |
| Penrhos Plant Hire Ltd | 01499563 | 15/03/1999 | Dissolved |
| TURBINE BOAT CHARTERS LIMITED | 07166793 | 23/02/2010 | Dissolved |
| WEST COAST DEVELOPMENT SERVICES LIMITED | 04111846 | 20/02/2001 | Dissolved |
| WEST COAST DEVELOPMENT SERVICES LIMITED | 04111846 | 20/02/2001 | Dissolved |
| WINDFARM VESSELS LIMITED | 07660692 | 07/06/2011 | Not Trading |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| CHURCH BAY LTD | 08001017 | 22/03/2012 | 25/10/2024 | Not Trading |
| HOLYHEAD BOATYARD LIMITED | 00724907 | 15/03/1999 | 25/10/2024 | Gold |
| HOLYHEAD BOATYARD LIMITED | 00724907 | 05/01/1998 | 25/10/2024 | Gold |
| HOLYHEAD TOWING COMPANY LIMITED | 00871758 | 15/03/1999 | 25/10/2024 | Gold |
| HOLYHEAD TOWING COMPANY LIMITED | 00871758 | 25/04/2000 | 25/10/2024 | Gold |
| MAINSTAY MARINE SOLUTIONS LIMITED | 08938325 | 13/03/2014 | 21/05/2014 | Silver |
| TURBINE TRANSFERS LIMITED | 06810857 | 05/02/2009 | 25/10/2024 | Not Trading |
| YNYS MON WINDFARM VESSELS LTD | 07776928 | 16/09/2011 | 25/10/2024 | Amber |