- FOOSH LIMITEDDisolved- 12211215 - Dissolved on 21 February 2025 
- QUANTUM U.K. LTDDisolved- 12393856 - Dissolved on 13 July 2021 
- QUANTUM S 1 LTDActive - Proposal to Strike off- 07073993 - Incorporated on 12 November 2009 
- 53 QUANTUM LTD- 05555986 - Incorporated on 7 September 2005 
- QUANTUM Z LTDActive - Proposal to Strike off- 08686688 - Incorporated on 11 September 2013 
- QUANTUM33 LTDActive - Proposal to Strike off- 08359550 - Incorporated on 14 January 2013 
- QUANTUM L LTDDisolved- 11108459 - Dissolved on 17 May 2022 
- QUANTUM Z LTDActive - Proposal to Strike off- 15579279 - Incorporated on 20 March 2024 
- QUANTUM M & D LTDActive - Proposal to Strike off- 07874371 - Incorporated on 7 December 2011 
- QUANTUM88 LTD- 12063029 - Incorporated on 21 June 2019 
- QUANTUM O2 LTD- 15823308 - Incorporated on 8 July 2024 
- QUANTUM U.K LTD- 14634492 - Incorporated on 2 February 2023 
- QUANTUM G LTD- 15139755 - Incorporated on 15 September 2023 
- QUANTUM3 LTDActive - Proposal to Strike off- 07348815 - Incorporated on 18 August 2010 
- QUANTUM S 2 LTDActive - Proposal to Strike off- 07074032 - Incorporated on 12 November 2009 
- QUANTUM&2 LTDDisolved- 12845805 - Dissolved on 21 June 2022 
- QUANTUM 2 LTDActive - Proposal to Strike off- 06979607 - Incorporated on 4 August 2009 
- QUANTUM D+M LTD.Active - Proposal to Strike off- 07115771 - Incorporated on 4 January 2010 
- QUANTUM S 3 LTDActive - Proposal to Strike off- 07073987 - Incorporated on 12 November 2009 
- QUANTUM44 LTD- NI620680 - Incorporated on 1 October 2013