- SIREN FX LTD- 14476514 - Incorporated on 10 November 2022 
- SIROUS LTDDisolved- SC771439 - Dissolved on 22 April 2025 
- SIR TECH LTDDisolved- 14932025 - Dissolved on 16 July 2024 
- SIREAN LTDActive - Proposal to Strike off- 15671238 - Incorporated on 23 April 2024 
- SIRENA LTDDisolved- 13648616 - Dissolved on 21 March 2023 
- SIRIUS7 LTD- 16170775 - Incorporated on 8 January 2025 
- SIRENA LTD- 16349264 - Incorporated on 27 March 2025 
- SIRJAH LTD- 16588106 - Incorporated on 17 July 2025 
- SIRDIY LTD- 14527178 - Incorporated on 7 December 2022 
- SIRACH LTD- 14955939 - Incorporated on 23 June 2023 
- SIRIBA LTD.Active - Proposal to Strike off- 10787862 - Incorporated on 24 May 2017 
- SIRUAN LTDDisolved- 15082760 - Dissolved on 4 March 2025 
- SIRON (UK) LTDDissolved- 06962440 - Dissolved on 17 December 2019 
- SIRAMS LTDDissolved- 06615435 - Dissolved on 24 July 2012 
- SIRIUS1 LTDActive - Proposal to Strike off- 07893001 - Incorporated on 28 December 2011 
- SIRVEU LTDActive - Proposal to Strike off- 09511320 - Incorporated on 26 March 2015 
- SIRWAY LTDActive - Proposal to Strike off- 08832946 - Incorporated on 6 January 2014 
- DEER SIR LTDActive - Proposal to Strike off- 09158817 - Incorporated on 4 August 2014 
- SIRASA LTD- 09233288 - Incorporated on 24 September 2014 
- SIRKOT LTDDisolved- 12873332 - Dissolved on 7 November 2023