- ANNIS & O'BRIEN LTD- 09633605 - Incorporated on 11 June 2015 
- J O'BRIEN 7 LIMITEDLiquidation- 08301638 - Incorporated on 21 November 2012 
- NIALL O'BRIEN LTDActive - Proposal to Strike off- 09567046 - Incorporated on 29 April 2015 
- GAVIN O'BRIEN LTD- 10706436 - Incorporated on 4 April 2017 
- KITTY O'BRIEN LTD- 13737740 - Incorporated on 11 November 2021 
- G O'BRIEN LIMITEDDisolved- 12979489 - Dissolved on 3 January 2023 
- O'BRIEN FELLOWS LIMITEDActive - Proposal to Strike off- 05400886 - Incorporated on 22 March 2005 
- O'BRIEN PAYROLL UK LIMITED- 04703306 - Incorporated on 19 March 2003 
- SIMONE’S TAKEAWAY LTDDisolved- 13032825 - Dissolved on 26 April 2022 
- SIMON&SIMONETTE LTDDissolved- 09861163 - Dissolved on 26 February 2019 
- MALIK-O'BRIEN LLPDissolved- OC325378 - Dissolved on 13 October 2009 
- D.W. O'BRIEN LIMITEDDisolved- 01099894 - Dissolved on 1 March 2022 
- D P O'BRIEN LIMITED- 07064464 - Incorporated on 3 November 2009 
- E. J. O'BRIEN LIMITED- 06339441 - Incorporated on 10 August 2007 
- ROGER O'BRIEN LTDActive - Proposal to Strike off- 07910154 - Incorporated on 16 January 2012 
- M O'BRIEN LIMITED- 07911506 - Incorporated on 16 January 2012 
- H E J O'BRIEN LIMITED- 04646753 - Incorporated on 24 January 2003 
- J. O'BRIEN LIMITED- 05653237 - Incorporated on 13 December 2005 
- P O'BRIEN LIMITED- 08610850 - Incorporated on 16 July 2013 
- J & K O'BRIEN LIMITED- 09506055 - Incorporated on 24 March 2015