- K J O'BRIEN LIMITED- 11237316 - Incorporated on 6 March 2018 
- REBEL O'BRIEN LTDActive - Proposal to Strike off- 12064456 - Incorporated on 21 June 2019 
- P & S O'BRIEN LIMITEDDisolved- 11086073 - Dissolved on 3 January 2023 
- O'BRIEN 72 LIMITED- 10432662 - Incorporated on 18 October 2016 
- O'BRIEN-PATEL LLP- OC436854 - Incorporated on 14 April 2021 
- JAMIE O'BRIEN LTDDisolved- 13833105 - Dissolved on 27 June 2023 
- BRIENZOLA LTDDisolved- 14147224 - Dissolved on 16 January 2024 
- MR & MRS S LTDActive - Proposal to Strike off- 12290244 - Incorporated on 30 October 2019 
- P & D O'BRIEN LIMITEDLiquidation- 05506949 - Incorporated on 13 July 2005 
- L M O'BRIEN LIMITEDActive - Proposal to Strike off- 11492382 - Incorporated on 31 July 2018 
- AGNES O'BRIEN LTDActive - Proposal to Strike off- 11455297 - Incorporated on 9 July 2018 
- DAVID P O’BRIEN LTD- 09952505 - Incorporated on 14 January 2016 
- FIONA O'BRIEN LTDDisolved- 13270286 - Dissolved on 23 August 2022 
- O'BRIENS BITS LTDDisolved- 13595741 - Dissolved on 17 October 2023 
- O'BRIEN HAULAGE SERVICES LTD.Liquidation- 10348879 - Incorporated on 27 August 2016 
- O'BRIEN SOLUTIONS GROUP LTDLiquidation- 09785413 - Incorporated on 21 September 2015 
- QUEENSPARK PROPERTY DEVELOPMENTS LIMITEDDissolved- 06889023 - Dissolved on 6 December 2016 
- EOB DRAINAGE LIMITEDDissolved- 09532661 - Dissolved on 10 July 2018 
- FERGAL O'BRIEN TRAINING LIMITED- 09586584 - Incorporated on 12 May 2015 
- RICHARD & RICHARD LIMITEDActive - Proposal to Strike off- 11534948 - Incorporated on 24 August 2018