| COX, Verity Claire ACTIVE | Secretary | 01 Jan 2026 | | | | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| POLLARD, Alexander ACTIVE | Secretary | 01 Apr 2022 | | | | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| MAY, Caroline Elizabeth ACTIVE | Director | 01 Nov 2024 | | United Kingdom | October 1980 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN, England |
| MEMMOTT, Robert William ACTIVE | Director | 01 Oct 2023 | | England | January 1973 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN, England |
| WEBSTER, Richard ACTIVE | Director | 31 Dec 2019 | | United Kingdom | December 1974 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| BLUNN, David Howard RESIGNED | Secretary | | 26 Nov 2013 | | | Sterling House, Brunel Road, Aylesbury, Buckinghamshire, HP19 8SS, England |
| BURWOOD, Krista RESIGNED | Secretary | 13 Dec 2018 | 31 Mar 2022 | | | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| PAVER, Michael RESIGNED | Secretary | 26 Nov 2013 | 31 Mar 2018 | | | Sterling Thermal Technology South Building, Brunel Road, Rabans Lane Industrial Area, Aylesbury, Buckinghamshire, HP19 8TD, England |
| TACKLEY, Kathryn Elizabeth RESIGNED | Secretary | 31 Mar 2018 | 13 Dec 2018 | | | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| WEBSTER, Richard RESIGNED | Secretary | 01 Apr 2022 | 31 Dec 2025 | | | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| ARMITAGE, Christopher Robert RESIGNED | Director | 18 Nov 2005 | 05 Jan 2015 | United Kingdom | July 1959 | Sterling House, Brunel Road, Aylesbury, Buckinghamshire, HP19 8SS, England |
| BLUNN, David Howard RESIGNED | Director | | 26 Nov 2013 | England | June 1951 | Sterling House, Brunel Road, Aylesbury, Buckinghamshire, HP19 8SS, England |
| BRIGHTMAN, Anthony Charles RESIGNED | Director | 28 Aug 2001 | 10 Mar 2003 | United Kingdom | July 1945 | 30 Heriot Row, Edinburgh, EH3 6EN |
| BUCKLEY, Peter Neville RESIGNED | Director | | 18 Nov 2005 | | September 1942 | 6 Albert Place, London, W8 5PD |
| BURWOOD, Krista RESIGNED | Director | 01 Dec 2020 | 31 Mar 2022 | England | April 1965 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| CARTWRIGHT, Jonathan Harry RESIGNED | Director | | 20 Jul 1998 | United Kingdom | August 1953 | Rectory Meadow, Hawthorn Place, Penn, Buckinghamshire, HP10 8EH |
| DENISON, Graeme Philip RESIGNED | Director | 13 Dec 2018 | 31 Dec 2019 | England | July 1960 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| DENMAN, Henry Wynne RESIGNED | Director | | 28 Mar 2002 | | July 1929 | The Penthouse Old Avenue, St Georges Hill, Weybridge, Surrey, KT13 0QB |
| DIGGINS, David Reginald RESIGNED | Director | | 30 May 2002 | | December 1948 | Fairgarden, Unity Lane, Misterton, Somerset, TA18 8NA |
| EDWARDS, Charles Hugh RESIGNED | Director | 24 Mar 2011 | 01 Apr 2015 | United Kingdom | November 1979 | Sterling House, Brunel Road, Aylesbury, Buckinghamshire, HP19 8SS, England |
| FLANAGAN, Sally Deborah RESIGNED | Director | 28 Aug 2013 | 14 Oct 2015 | England | September 1962 | Sterling House, Brunel Road, Aylesbury, Buckinghamshire, HP19 8SS, England |
| HUSSEY, David Gordon RESIGNED | Director | 02 Dec 2013 | 22 Jun 2018 | England | June 1948 | Long Springs, Valley Farm Road, Melton, Woodbridge, Suffolk, IP12 1LJ, England |
| KINLOCH, David Oliphant, Sir RESIGNED | Director | | 03 Nov 2003 | | January 1942 | 29 Walpole Street, London, SW3 4QS |
| LEWIS, Timothy Richard Gwynne RESIGNED | Director | 01 Apr 2015 | 13 Dec 2018 | England | January 1978 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| LIVETT, Timothy James RESIGNED | Director | 01 Dec 2020 | 30 Sep 2023 | England | June 1962 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| PAVER, Michael RESIGNED | Director | 21 Aug 2013 | 31 Mar 2018 | United Kingdom | January 1955 | Sterling Thermal Technology South Building, Brunel Road, Rabans Lane Industrial Area, Aylesbury, Buckinghamshire, HP19 8TD, England |
| RADFORD, David Michael RESIGNED | Director | | 27 Jul 1993 | | November 1930 | 5 Witney Close, Ickenham, Uxbridge, Middlesex, UB10 8EL |
| ROBSON, Thomas Richard RESIGNED | Director | 01 Apr 2022 | 31 Oct 2024 | England | November 1982 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| WEEKS, Jeffrey Martin RESIGNED | Director | 16 Feb 2015 | 14 Oct 2015 | Usa | May 1955 | Sterling House, Brunel Road, Aylesbury, Buckinghamshire, HP19 8SS, England |
| WHITELEY, Paul Martin RESIGNED | Director | 13 Dec 2018 | 31 Dec 2020 | United Kingdom | February 1959 | Cayzer House, 30 Buckingham Gate, London, SW1E 6NN |
| WYATT, Michael Gerald, Major RESIGNED | Director | | 28 Mar 2002 | United Kingdom | July 1937 | Pippin Park, Lidgate, Newmarket, Suffolk, CB8 9PP |
| WYATT, William Penfold RESIGNED | Director | 01 Jul 1999 | 13 Mar 2014 | England | May 1968 | Sterling House, Brunel Road, Aylesbury, Buckinghamshire, HP19 8SS, England |