| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| British Borneo Expro Ltd | FC020183 | 04/03/1997 | Dissolved |
| LANDER CONSULTING LTD | 03665349 | 25/04/2014 | Bronze |
| Tuskar Oil & Gas Ltd | 01536680 | 11/02/1998 | Dissolved |
| VECTIS PETROLEUM LIMITED | 03452334 | 31/03/2000 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| AL HAJ PAKISTAN EXPLORATION LIMITED | 01164960 | 10/03/1995 | 24/04/1995 | Bronze |
| ALKANE ENERGY LIMITED | 02966946 | 04/06/2004 | 31/10/2012 | Gold |
| Balmuir Resources Ltd | SC159368 | 09/08/1995 | 09/02/1996 | Dissolved |
| CNS (MAUREEN) LIMITED | SC344161 | 04/08/2008 | 01/11/2012 | Dissolved |
| Caber Oil Ltd | SC049154 | 10/05/1990 | 27/02/1995 | Dissolved |
| ENI ANS LIMITED | 02554093 | 19/01/1996 | 29/10/1997 | Dissolved |
| ENI COTE D'IVOIRE LIMITED | 02556415 | 19/01/1996 | 29/10/1997 | Amber |
| ENI HEWETT LIMITED | SC090159 | 08/01/2001 | 16/04/2004 | Silver |
| ENI UKCS LIMITED | 01019748 | 19/01/1996 | 29/10/1997 | Gold |
| EXCALIBUR EXPLORATION LIMITED | 03059175 | 01/11/2013 | 02/05/2017 | Dissolved |
| FIRST OIL EXPRO LIMITED | 01021486 | 11/02/1998 | 26/04/1999 | Dissolved |
| FIRST OIL UK HOLDINGS LIMITED | 01282732 | 11/02/1998 | 26/04/1999 | Dissolved |
| KINGSVIEW IOW FREEHOLD LIMITED | 07563866 | 30/12/2012 | 16/11/2023 | Silver |
| MAGHREB OFFSHORE LIMITED | 01057332 | 10/03/1995 | 18/12/1995 | Dissolved |
| MEDOIL PLC | 05220759 | 02/12/2004 | 10/10/2007 | Dissolved |
| Macmillan Natural Resources Ltd | 01010995 | 10/03/1995 | 18/12/1995 | Dissolved |
| OPHIR ENERGY LIMITED | 05047425 | 18/11/2008 | 28/02/2014 | Bronze |
| PENTANE ENERGY LIMITED | SC323717 | 28/02/2008 | 01/11/2012 | Dissolved |
| PREMCO PETROLEUM (OIL AND GAS) LIMITED | 00868620 | 10/03/1995 | 18/12/1995 | Dissolved |
| PREMIER ENERGY ENTERPRISES LIMITED | 01164959 | 10/03/1995 | 18/12/1995 | Dissolved |
| PREMIER OIL (NW NATUNA) LIMITED | 00963192 | 10/03/1995 | 18/12/1995 | Dissolved |
| PREMIER OIL ABERDEEN SERVICES LIMITED | 01164961 | 10/03/1995 | 18/12/1995 | Bronze |
| PREMIER OIL EXPLORATION LIMITED | SC021265 | 10/03/1995 | 18/12/1995 | Amber |
| PREMIER OIL FAR EAST LIMITED | 01135444 | 10/03/1995 | 18/12/1995 | Gold |
| PREMIER OIL GROUP LIMITED | SC017829 | 27/02/1995 | 18/12/1995 | Gold |
| PREMIER OIL SOUTH ANDAMAN LIMITED | 01474678 | 10/03/1995 | 18/12/1995 | Amber |
| PREMIER OIL UK LIMITED | SC048705 | 28/02/1989 | 18/12/1995 | Silver |
| Parambe Oil & Gas Operations Ltd | 01121594 | 10/03/1995 | 18/12/1995 | Dissolved |
| Pict Petroleum (Tunisia) Limited | SC141224 | 07/12/1992 | 18/12/1995 | Dissolved |
| Premier Oil Dorset Ltd | 01165601 | 10/03/1995 | 18/12/1995 | Dissolved |
| Premier Oil Halmahera Ltd | 00560601 | 10/03/1995 | 20/09/1995 | Dissolved |
| Premier Oil Pangkah Ltd | 01012762 | 10/03/1995 | 20/09/1995 | Dissolved |
| Rocky Mountains Oil & Gas Ltd | 01505884 | 10/03/1995 | 18/12/1995 | Dissolved |
| SPIRIT ENERGY NORTH SEA LIMITED | 04594558 | 10/06/2003 | 16/04/2004 | Silver |
| TRAJAN RESOURCES LIMITED | 08133275 | 01/11/2013 | 30/01/2019 | Dissolved |
| TULLOW OIL PLC | 03919249 | 23/03/2001 | 16/04/2004 | Silver |