- SIRINI LTDDisolved- 12862716 - Dissolved on 8 February 2022 
- SIRIUS 2020 LTDDisolved- 11513558 - Dissolved on 18 October 2022 
- SIRATT LTDDisolved- 09977809 - Dissolved on 8 July 2025 
- SIRACH109 LTD- 11094316 - Incorporated on 4 December 2017 
- SIRENA LLP- OC426065 - Incorporated on 15 February 2019 
- SIRROM LTD- 12001722 - Incorporated on 17 May 2019 
- SIR MAMA LTDDisolved- 13447675 - Dissolved on 20 December 2022 
- 4SIRENS LTDDisolved- 13330192 - Dissolved on 19 September 2023 
- SIRDIY LTDDisolved- 13268306 - Dissolved on 2 August 2022 
- SIRONE LTD- 12919701 - Incorporated on 1 October 2020 
- SIRAIS LTD- 16519278 - Incorporated on 16 June 2025 
- SIRACO LTDActive - Proposal to Strike off- 11645583 - Incorporated on 26 October 2018 
- SIRAAT LTD- 11554797 - Incorporated on 5 September 2018 
- SIRPHI LTDDisolved- 12642744 - Dissolved on 18 February 2025 
- SIRAJI LTDActive - Proposal to Strike off- 11905571 - Incorporated on 26 March 2019 
- SIRIUS93 LTD- 08135934 - Incorporated on 10 July 2012 
- SIRAAT LTDActive - Proposal to Strike off- 06784126 - Incorporated on 6 January 2009 
- SIRROM LTDDissolved- 07455851 - Dissolved on 19 March 2013 
- SIRETT LTD- 07465890 - Incorporated on 10 December 2010 
- SIRECO LTD- 06364650 - Incorporated on 7 September 2007