| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| DIAMOND OFFSHORE ENTERPRISES LIMITED | 06747036 | 04/09/2024 | Amber |
| DIAMOND OFFSHORE LIMITED | 00943475 | 04/09/2024 | Bronze |
| DIAMOND RIG INVESTMENTS LIMITED | 06772372 | 04/09/2024 | Bronze |
| NOBLE DRILLING UK LTD | 07672698 | 03/08/2020 | Silver |
| NOBLE HIGHLANDER UK LTD | 10195411 | 03/08/2020 | Silver |
| NOBLE OFFSHORE DRILLING (UK) LTD | 02767959 | 04/09/2024 | Amber |
| UK DRILLING CONTRACTORS ASSOCIATION LIMITED | SC202909 | 10/06/2019 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| HUMBERSIDE OFFSHORE TRAINING ASSOCIATION | 02190605 | 25/04/2003 | 19/08/2009 | One Red Flag |
| MAERSK PENSION TRUSTEE LIMITED | 06272753 | 12/08/2010 | 04/04/2019 | Dissolved |
| UK DRILLING CONTRACTORS ASSOCIATION LIMITED | SC202909 | 02/02/2005 | 30/01/2012 | Dissolved |
| UK FLOATING PRODUCTION OPERATORS ASSOCIATION LIMITED | SC210738 | 15/02/2001 | 01/10/2012 | Dissolved |