| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| IRH RECONSTRUCTION LIMITED | 00651550 | 17/10/1991 | Dissolved |
| LIGHTING DESIGN CENTRE LIMITED(THE) | 01685404 | 17/10/1991 | Dissolved |
| R. T. HARRIS & SON (BUILDING SERVICES) LIMITED | 02292892 | 12/09/1991 | Dissolved |
| R.T.H. HOLDINGS LIMITED | 11030307 | 26/10/2017 | Bronze |
| R.T.HARRIS & SON (ELECTRICAL CONTRACTORS) LIMITED | 02058345 | 17/10/1991 | Silver |
| RTH HARRIS PROPERTY LIMITED | 12014352 | 23/05/2019 | Not Trading |
| RTH HARRIS TRADING LIMITED | 11726502 | 13/12/2018 | Not Trading |
| THE FOUNDATION OF THOMAS DAWSON | 14903860 | 30/05/2023 | Bronze |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| COMPEX CERTIFICATION LIMITED | 02336110 | 11/03/2004 | 10/12/2012 | One Red Flag |
| ELECTRICAL CONTRACTORS ASSOCIATION LIMITED(THE) | 00143669 | 26/01/1994 | 23/01/2002 | Gold |
| HARRIS 2014 LIMITED | 08924862 | 05/03/2014 | 24/10/2023 | Bronze |
| JTL | 03958541 | 11/12/2002 | 10/12/2012 | Silver |
| NATIONAL ELECTROTECHNICAL TRAINING ORGANISATION | 03389705 | 24/09/1999 | 12/11/2015 | Silver |
| SUMMITSKILLS LIMITED | 04575759 | 15/01/2004 | 01/12/2005 | Dissolved |
| THE ELECTRICAL INDUSTRIES CHARITY LIMITED | 02726030 | 25/06/1998 | 20/06/2000 | Silver |