| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| BIRCH SITES LIMITED | 06404382 | 01/09/2023 | Silver |
| NATIONAL GRID ENERGY METERING LIMITED | 09575002 | 01/09/2023 | Not Trading |
| NATIONAL GRID GRAIN LNG LIMITED | 04463679 | 01/09/2023 | Gold |
| NATIONAL GRID INTERCONNECTOR HOLDINGS LIMITED | 08169384 | 01/09/2023 | Silver |
| NATIONAL GRID PROPERTY HOLDINGS LIMITED | 03797578 | 01/09/2023 | Silver |
| NATIONAL GRID TWENTY EIGHT LIMITED | 07926588 | 01/09/2023 | Gold |
| NATIONAL GRID TWENTY SEVEN LIMITED | 07926596 | 01/09/2023 | Silver |
| NATIONAL GRID WILLIAM LIMITED | 07290232 | 01/09/2023 | Not Trading |
| PORT GREENWICH LIMITED | 02392867 | 01/09/2023 | Gold |
| THAMESPORT INTERCHANGE LIMITED | 06404380 | 01/09/2023 | Gold |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| BRITISH GAS FINANCE LIMITED | 06796004 | 01/04/2014 | 28/03/2018 | Silver |
| BRITISH GAS INSURANCE LIMITED | 06608316 | 03/03/2015 | 24/10/2017 | Gold |
| BRITISH GAS NEW HEATING LIMITED | 06723244 | 01/04/2014 | 10/10/2016 | Bronze |
| BRITISH GAS SERVICES LIMITED | 03141243 | 15/05/2014 | 28/03/2018 | Silver |
| CENTRICA BETA HOLDINGS LIMITED | 04710850 | 01/01/2018 | 18/11/2019 | Silver |
| CENTRICA COMBINED COMMON INVESTMENT FUND LIMITED | 04541886 | 04/03/2013 | 31/05/2019 | Not Trading |
| CENTRICA ENERGY MARKETING LIMITED | 08807923 | 09/12/2013 | 11/12/2013 | Silver |
| CENTRICA FINANCE (CANADA) LIMITED | 04055254 | 01/01/2018 | 18/11/2019 | Dissolved |
| CENTRICA FINANCE (SCOTLAND) LIMITED | SC436640 | 01/01/2018 | 18/11/2019 | Gold |
| CENTRICA FINANCE (US) LIMITED | 04140765 | 01/01/2018 | 18/11/2019 | Dissolved |
| CENTRICA GAMMA HOLDINGS LIMITED | 04710840 | 01/01/2018 | 18/11/2019 | Gold |
| CENTRICA HYDROGEN INNOVATIONS LIMITED | 06795997 | 01/01/2018 | 18/11/2019 | Silver |
| CENTRICA LAKE LIMITED | 09223347 | 01/01/2018 | 18/11/2019 | Silver |
| CENTRICA OVERSEAS HOLDINGS LIMITED | 03922153 | 01/01/2018 | 18/11/2019 | Gold |
| CENTRICA SERVICES LIMITED | 10553056 | 01/01/2018 | 18/11/2019 | Amber |
| DYNO-ROD LIMITED | 01046906 | 01/09/2014 | 10/10/2016 | Gold |
| GB GAS HOLDINGS LIMITED | 03186121 | 01/01/2018 | 18/11/2019 | Silver |
| NATIONAL GAS TRANSMISSION HOLDINGS LIMITED | 03675375 | 21/07/2020 | 01/08/2021 | Amber |
| NATIONAL GAS TRANSMISSION PLC | 02006000 | 30/04/2020 | 01/08/2021 | Silver |
| NATIONAL GRID ELECTRICITY TRANSMISSION PLC | 02366977 | 30/04/2020 | 01/08/2021 | Silver |
| NGET/SPT UPGRADES LIMITED | 07057886 | 03/04/2020 | 22/09/2021 | One Red Flag |