| Adam David Christopher Westley | Director | 20 Sept 2018 | 2 Sept 2019 | British | 57 years |
| Alan William Mcculloch | Director | 2 Sept 2019 | 30 Jul 2021 | British | 60 years |
| Andrew William Hodges | Director | 30 Jun 2016 | 12 Jul 2018 | British | 59 years |
| Anne Garrihy | Director | 24 Sept 1997 | 18 Jul 2001 | British | 66 years |
| Centrica Directors Limited | Corporate Director | 1 Nov 2001 | 29 Jun 2004 | United Kingdom | - |
| Combined Nominees Limited | Corporate Nominee Director | 4 Nov 1996 | 24 Sept 1997 | United Kingdom | - |
| Combined Secretarial Services Limited | Corporate Nominee Director | 4 Nov 1996 | 24 Sept 1997 | United Kingdom | - |
| Ian Grant Dawson | Director | 24 Sept 1997 | 31 Jan 2000 | British | 67 years |
| Ian Grant Dawson | Director | 29 Jun 2004 | 18 Dec 2012 | British | 67 years |
| Ian Ritchie | Director | 31 Jan 2000 | 1 Nov 2001 | British | 74 years |
| Jeffrey Bell | Director | 30 Jul 2010 | 18 Dec 2012 | Canadian | 59 years |
| Justine Michelle Campbell | Director | 12 Jul 2018 | 20 Sept 2018 | British | 56 years |
| Lucy Elizabeth Caldwell | Director | 26 Jul 1999 | 1 Nov 2001 | British | 58 years |
| Lucy Elizabeth Caldwell | Secretary | 21 Nov 1997 | 9 Aug 2000 | British | - |
| Moira Lynne Turner | Director | 22 Jul 2009 | 30 Jul 2010 | British | 64 years |
| Nicola Carroll | Director | 18 Dec 2012 | 30 Jun 2016 | British | 67 years |
| Paul Ian Hedley | Director | 26 Sept 2008 | 22 Jul 2009 | British | 57 years |
| Phillip Keague Bentley | Director | 29 Jun 2004 | 18 Mar 2008 | British | 67 years |
| Steven Leven | Director | 18 Jul 2001 | 1 Nov 2001 | British | 59 years |
| Teresa Jane Furmston | Director | 24 Sept 1997 | 22 Feb 1999 | British | 59 years |
| Teresa Jane Furmston | Secretary | 24 Sept 1997 | 21 Nov 1997 | British | - |