| BERNSAND, Charlotta Sofia ACTIVE | Secretary | 31 Jan 2023 | | | | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| BYRNE, David ACTIVE | Secretary | 19 Jul 2022 | | | | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| AUER, Liam Patrick ACTIVE | Director | 06 Jan 2025 | | United Kingdom | May 1989 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| DALVAI, Anita ACTIVE | Director | 16 Jul 2026 | | United Kingdom | December 1987 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| DELA CRUZ, Jenny Lyn ACTIVE | Director | 29 Jan 2024 | | England | December 1990 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| DIVOKY, Jerry James ACTIVE | Director | 31 Jan 2023 | | Canada | August 1966 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| HIGGINS, Howard Charles ACTIVE | Director | 31 Jan 2023 | | United Kingdom | March 1953 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| PRICE, William David George ACTIVE | Director | 04 Sep 2026 | | England | September 1984 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| WATSON, Robin ACTIVE | Director | 21 Mar 2025 | | United Kingdom | February 1967 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| BARNES, Megan RESIGNED | Secretary | 30 Nov 2018 | 19 Jul 2022 | | | 1-3 Strand, London, WC2N 5EH |
| CLAYTON, Karen Ann RESIGNED | Secretary | 25 Jan 2010 | 12 Sep 2014 | | | 1-3 Strand, London, WC2N 5EH |
| DAVIDSON, Rachael Jennifer RESIGNED | Secretary | 11 Feb 2015 | 28 Mar 2018 | | | 1-3 Strand, London, WC2N 5EH |
| DURRANT, Andrew Peter RESIGNED | Secretary | 28 Jun 2007 | 19 Oct 2007 | | | 340 Sidegate Lane, Ipswich, Suffolk, IP4 3DW |
| FORWARD, David Charles RESIGNED | Secretary | 19 Oct 2007 | 30 Nov 2013 | | | 1-3 Strand, London, WC2N 5EH |
| HAGAN, Lawrence RESIGNED | Secretary | 28 Mar 2018 | 31 Jan 2023 | | | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| MAHY, Helen Margaret RESIGNED | Secretary | 31 Mar 2002 | 25 Jan 2010 | | | 1-3 Strand, London, WC2N 5EH |
| MORGAN, Alice Parker RESIGNED | Secretary | 17 Mar 2016 | 30 Nov 2018 | | | 1-3 Strand, London, WC2N 5EH |
| MUNSEY, Jonathan Ross RESIGNED | Secretary | 21 Sep 2010 | 22 May 2012 | | | 1-3 Strand, London, WC2N 5EH |
| PATIENCE, Donald William John RESIGNED | Secretary | 27 Sep 1999 | 31 Mar 2002 | | | Burnside Little Ann, Abbotts Ann, Andover, Hampshire, SP11 7NW |
| RAYNER, Heather Maria RESIGNED | Secretary | 24 Mar 2014 | 17 Mar 2016 | | | 1-3 Strand, London, WC2N 5EH |
| COMBINED SECRETARIAL SERVICES LIMITED RESIGNED | Nominee Secretary | 27 Nov 1998 | 21 Jul 1999 | | | Victoria House, 64 Paul Street, London, EC2A 4NG |
| HACKWOOD SECRETARIES LIMITED RESIGNED | Nominee Secretary | 21 Jul 1999 | 27 Sep 1999 | | | One Silk Street, London, EC2Y 8HQ |
| AGG, Andrew Jonathan RESIGNED | Director | 01 Jun 2013 | 13 Apr 2018 | England | October 1969 | 1-3 Strand, London, WC2N 5EH |
| AGOUMI, Mia RESIGNED | Director | 31 Jan 2023 | 11 Mar 2024 | United Kingdom | March 1985 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| ALLSOPP, Julian Peter RESIGNED | Director | 01 Jun 2013 | 01 Oct 2016 | United Kingdom | March 1971 | 1-3 Strand, London, WC2N 5EH |
| BUCK, Colin RESIGNED | Director | 03 Jun 2003 | 30 Jun 2006 | England | August 1949 | 8 Northumberland Road, Leamington Spa, Warwickshire, CV32 6HA |
| BURRARD-LUCAS, Stephen Charles RESIGNED | Director | 23 Oct 2000 | 18 Jan 2010 | United Kingdom | April 1954 | 1-3 Strand, London, WC2N 5EH |
| CANN, John William Anthony RESIGNED | Director | 21 Jul 1999 | 27 Sep 1999 | England | July 1947 | 13 Murray Road, London, SW19 4PD |
| COOPER, Malcolm Charles RESIGNED | Director | 23 Oct 2000 | 01 Jan 2016 | United Kingdom | June 1959 | 1-3 Strand, London, WC2N 5EH |
| DICKIE, Kylee Marie RESIGNED | Director | 31 Jan 2023 | 11 Mar 2024 | United Kingdom | June 1981 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| FAIRBAIRN, Mark Robert RESIGNED | Director | 01 Jun 2003 | 25 Mar 2011 | England | November 1958 | 1-3 Strand, London, WC2N 5EH |
| FARKAS, David RESIGNED | Director | 21 Oct 2024 | 28 Feb 2025 | England | October 1975 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| FITZGERALD, Emma RESIGNED | Director | 01 Jul 2013 | 30 Apr 2015 | England | January 1967 | 1-3 Strand, London, WC2N 5EH |
| FOSTER, Alan Peter RESIGNED | Director | 01 Jan 2016 | 21 Jul 2020 | United Kingdom | March 1971 | 1-3 Strand, London, WC2N 5EH |
| HAMPTON, Philip Roy RESIGNED | Director | 27 Sep 1999 | 23 Oct 2000 | | October 1953 | Blakeney, Pennymead Rise, East Horsley, Leatherhead, Surrey, KT24 5AL |
| HOLLIDAY, Steven John RESIGNED | Director | 01 Jun 2003 | 18 Jan 2010 | United Kingdom | October 1956 | Waterside House, 35 North Wharf Road, London, W2 1NW |
| HOOPER, Nick RESIGNED | Director | 01 Aug 2021 | 31 Jan 2023 | United Kingdom | December 1975 | 1-3 Strand, London, WC2N 5EH |
| HUMPHREYS, Stuart Calvin RESIGNED | Director | 01 Apr 2011 | 31 May 2013 | England | February 1963 | 1-3 Strand, London, WC2N 5EH |
| HUMPHRIES-NEW, Natalie RESIGNED | Director | 31 Jan 2023 | 26 Sep 2024 | England | February 1975 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| JONES, Eric Paul RESIGNED | Director | 27 Sep 1999 | 23 Oct 2000 | | March 1948 | Tarbay Farmhouse, Tarbay Lane Oakley Green, Windsor, Berkshire, SL4 4QG |
| KEELING, Timothy RESIGNED | Director | 04 Mar 2023 | 30 Nov 2023 | Canada | September 1985 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| KELLY, Rhian Catriona RESIGNED | Director | 31 Jan 2023 | 11 Mar 2024 | United Kingdom | December 1976 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| LEWIS, Alexandra Morton RESIGNED | Director | 13 Apr 2018 | 31 Jan 2023 | England | January 1972 | 1-3 Strand, London, WC2N 5EH |
| MARRIAGE, Jeremy Peter RESIGNED | Director | 21 Jul 1999 | 27 Sep 1999 | United Kingdom | May 1947 | 12 Patten Road, London, SW18 3RH |
| MATHIESON, Mark William RESIGNED | Director | 31 Jan 2023 | 15 May 2026 | England | September 1966 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| MATTHEWS, Colin Stephen RESIGNED | Director | 12 Nov 2001 | 20 Oct 2002 | United Kingdom | April 1956 | Brae Cottage Bute Avenue, Richmond, Surrey, TW10 7AX |
| MURRAY, Christopher John RESIGNED | Director | 11 Feb 2016 | 27 Jul 2016 | England | April 1956 | 1-3 Strand, London, WC2N 5EH |
| NOLAN, Philip, Doctor RESIGNED | Director | 27 Sep 1999 | 31 Dec 2001 | | October 1953 | Fernside, Killiney Hill Road, Killiney, County Dublin, Republic Of Ireland |
| PETTIGREW, John Mark RESIGNED | Director | 01 Apr 2011 | 11 Feb 2016 | United Kingdom | October 1968 | 1-3 Strand, London, WC2N 5EH |
| PHAM, Nghi Do Truong RESIGNED | Director | 04 Mar 2023 | 21 Jul 2023 | Canada | September 1977 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| PRICE, William David George RESIGNED | Director | 31 Jan 2023 | 15 May 2026 | England | September 1984 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| QURESHI, Abdul Moiz RESIGNED | Director | 21 Jul 2023 | 16 Jul 2026 | England | August 1986 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| REES, David Rocyn RESIGNED | Director | 12 Nov 2001 | 21 Oct 2002 | | April 1959 | Linden Lodge, Hunningham, Leamington Spa, Warwickshire, CV33 9DR |
| SHAW, Lucy Nicola RESIGNED | Director | 27 Jul 2016 | 05 Nov 2021 | England | May 1969 | 1-3 Strand, London, WC2N 5EH |
| TODD, Alistair Mark RESIGNED | Director | 21 Jul 2020 | 01 Aug 2021 | United Kingdom | November 1975 | 1-3 Strand, London, WC2N 5EH |
| TSIRIMPA, Aikaterini RESIGNED | Director | 31 Jan 2023 | 26 Sep 2024 | United Kingdom | April 1981 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| VARNEY, David Robert RESIGNED | Director | 27 Sep 1999 | 23 Oct 2000 | | May 1946 | River Thatch The Abbotsbrook, Bourne End, Buckinghamshire, SL8 5QU |
| VERRION, Robert Edward RESIGNED | Director | 27 Sep 1999 | 01 Jun 2003 | England | October 1952 | 1, Sharmans Cross Road, Solihull, West Midlands, B91 1RG |
| WEBB, Lincoln Hillier RESIGNED | Director | 31 Jan 2023 | 21 Oct 2024 | Canada | March 1971 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| WILSON, Benjamin Hollis RESIGNED | Director | 22 Nov 2021 | 26 Sep 2024 | United Kingdom | August 1974 | National Grid House, Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA |
| WILTSHIRE, Adam Simon RESIGNED | Director | 24 Jul 2006 | 03 Jun 2013 | England | May 1965 | 1-3 Strand, London, WC2N 5EH |
| WINSER, Nicholas Paul RESIGNED | Director | 01 Apr 2011 | 01 Jul 2015 | England | September 1960 | 1-3 Strand, London, WC2N 5EH |
| WOOLLACOTT, Paul Nicholas RESIGNED | Director | 27 Sep 1999 | 12 Nov 2001 | | October 1947 | Parfitts, Rectory Lane, Aston Tirrold, Oxfordshire, OX11 9DH |
| WYBREW, John Bryan RESIGNED | Director | 27 Sep 1999 | 03 Jun 2003 | United Kingdom | October 1941 | Langhurst Lodkin Hill, Hascombe, Godalming, Surrey, GU8 4JP |
| COMBINED NOMINEES LIMITED RESIGNED | Nominee Director | 27 Nov 1998 | 21 Jul 1999 | | | Victoria House, 64 Paul Street, London, EC2A 4NA |
| COMBINED SECRETARIAL SERVICES LIMITED RESIGNED | Nominee Director | 27 Nov 1998 | 21 Jul 1999 | | | Victoria House, 64 Paul Street, London, EC2A 4NG |