| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| Bt Cellnet Ltd | 04196992 | 29/11/2001 | Dissolved |
| CALL CONNECTIONS LIMITED | 02712995 | 02/12/2015 | Dissolved |
| Cellphones Direct (Holdings) Ltd | 03065866 | 01/12/2015 | Dissolved |
| DX COMMUNICATIONS (EDINBURGH) LIMITED | SC144905 | 01/12/2015 | Dissolved |
| LUMINA HOLDINGS LIMITED | 02667014 | 06/09/2016 | Dissolved |
| O2 CREDIT VOUCHERS LIMITED | 04273243 | 07/12/2015 | Dissolved |
| O2 MOBILES LIMITED | 02604355 | 02/12/2015 | Dissolved |
| O2 SOLUTIONS LIMITED | 01814089 | 02/12/2015 | Dissolved |
| O2 THIRD GENERATION | 03900219 | 01/10/2012 | Dissolved |
| O2 TRANSACTIONS LIMITED | 02713001 | 02/12/2015 | Dissolved |
| PACIFIC SHELF 873 LIMITED | SC198346 | 01/12/2015 | Dissolved |
| TELEFONICA FINANCIAL SERVICES UK LIMITED | 07584114 | 07/12/2015 | Dissolved |
| TELEFONICA UK PENSION TRUSTEE LIMITED | 04267552 | 07/06/2002 | Not Trading |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| AIRWAVE SOLUTIONS LIMITED | 03985643 | 10/11/2000 | 20/04/2007 | One Red Flag |
| CALL CONNECTIONS LIMITED | 02712995 | 04/05/2001 | 30/04/2014 | Dissolved |
| CELLPHONES DIRECT (INVESTMENTS) LIMITED | 03066790 | 04/05/2001 | 30/04/2014 | Dissolved |
| CELLPHONES DIRECT LIMITED | 02995222 | 04/05/2001 | 30/04/2014 | Dissolved |
| CELLULAR RADIO LIMITED | 01612599 | 02/12/2015 | 27/03/2020 | One Red Flag |
| Cellphones Direct (Holdings) Ltd | 03065866 | 04/05/2001 | 30/04/2014 | Dissolved |
| DX COMMUNICATIONS (EDINBURGH) LIMITED | SC144905 | 04/05/2001 | 30/04/2014 | Dissolved |
| DX COMMUNICATIONS LIMITED | SC133682 | 01/12/2015 | 27/03/2020 | One Red Flag |
| GENIE INTERNET LIMITED | 04330446 | 28/11/2001 | 30/04/2014 | Dissolved |
| GIFFGAFF LIMITED | 04196996 | 20/05/2002 | 13/11/2013 | Gold |
| LINK FS LIMITED | 03357545 | 15/09/2006 | 30/04/2014 | Dissolved |
| LUMINA HOLDINGS LIMITED | 02667014 | 04/05/2001 | 30/04/2014 | Dissolved |
| MMO2 LIMITED | 04190833 | 31/10/2006 | 07/07/2016 | Not Trading |
| MMO2 LIMITED | 04190833 | 31/12/2007 | 29/03/2018 | Not Trading |
| MOVISTAR LIMITED | 04101371 | 19/11/2001 | 30/04/2014 | Dissolved |
| O2 (EUROPE) LIMITED | 04247143 | 05/07/2001 | 27/03/2020 | Silver |
| O2 (ONLINE) LIMITED | 01906156 | 02/12/2015 | 27/03/2020 | Dissolved |
| O2 (UK) LIMITED | 02012647 | 01/12/2015 | 27/03/2020 | Not Trading |
| O2 CEDAR LIMITED | 04678681 | 26/02/2003 | 27/03/2020 | Gold |
| O2 COMMUNICATIONS LIMITED | 04271548 | 19/11/2001 | 30/04/2014 | One Red Flag |
| O2 CREDIT VOUCHERS LIMITED | 04273243 | 20/05/2002 | 30/04/2014 | Dissolved |
| O2 HOLDINGS LIMITED | 02604354 | 31/12/2007 | 29/03/2018 | Bronze |
| O2 INTERNATIONAL HOLDINGS LIMITED | 04247157 | 05/07/2001 | 27/03/2020 | Dissolved |
| O2 LIMITED | 04330445 | 28/11/2001 | 30/04/2014 | Dissolved |
| O2 MOBILES LIMITED | 02604355 | 19/11/2001 | 30/04/2014 | Dissolved |
| O2 NETWORKS LIMITED | 02604351 | 19/11/2001 | 27/03/2020 | Gold |
| O2 OAK LIMITED | 03646040 | 02/10/1998 | 30/04/2014 | Not Trading |
| O2 PINE LIMITED | 06281240 | 01/12/2015 | 27/03/2020 | Not Trading |
| O2 REDWOOD LIMITED | 02383186 | 04/05/2001 | 30/04/2014 | One Red Flag |
| O2 SOLUTIONS LIMITED | 01814089 | 04/05/2001 | 30/04/2014 | Dissolved |
| O2 THIRD GENERATION | 03900219 | 01/10/2012 | 30/04/2014 | Dissolved |
| O2 TRANSACTIONS LIMITED | 02713001 | 04/05/2001 | 30/04/2014 | Dissolved |
| O2 UNIFY LIMITED | 07999361 | 25/10/2012 | 30/04/2013 | Gold |
| O2 WILLOW LIMITED | 06281241 | 01/12/2015 | 27/03/2020 | Not Trading |
| O2 WORLDWIDE LIMITED | 09690368 | 16/07/2015 | 27/03/2020 | Bronze |
| PACIFIC SHELF 873 LIMITED | SC198346 | 04/05/2001 | 30/04/2014 | Dissolved |
| SKY HOME COMMUNICATIONS LIMITED | 05262862 | 03/10/2007 | 30/04/2013 | Not Trading |
| TELEFONICA DIGITAL LIMITED | 07884976 | 16/12/2011 | 20/12/2012 | Amber |
| TELEFONICA FINANCIAL SERVICES UK LIMITED | 07584114 | 30/03/2011 | 02/11/2011 | Dissolved |
| TELEFONICA GERMANY HOLDINGS LIMITED | 08202391 | 05/09/2012 | 27/03/2020 | Silver |
| TELEFONICA GLOBAL RESOURCES LIMITED | 02664011 | 04/05/2001 | 30/04/2014 | Dissolved |
| TELEFONICA O2 HOLDINGS LIMITED | 05310128 | 31/10/2006 | 27/03/2020 | Silver |
| TELEFONICA O2 UK LIMITED | 04330394 | 28/11/2001 | 30/04/2014 | Not Trading |
| TELEFONICA UK HOLDINGS LIMITED | 03722259 | 01/12/2015 | 27/03/2020 | Not Trading |
| TELEFONICA UK LIMITED | 01743099 | 19/11/2001 | 24/04/2014 | Gold |
| THE LINK STORES LIMITED | 03317483 | 15/09/2006 | 30/04/2014 | Not Trading |
| THE MOBILE PHONE STORE LIMITED | 02837875 | 28/03/2003 | 30/04/2014 | One Red Flag |
| VMED O2 SECRETARIES LIMITED | 04272689 | 17/08/2001 | 27/03/2020 | One Red Flag |
| WEVE LIMITED | 08178832 | 02/12/2015 | 25/08/2016 | Silver |