- IRWIN & ASSOCIATES LIMITED- 09655705 - Incorporated on 24 June 2015 
- IRWIN SECURITY LIMITED- NI617102 
- IRWIN COMPOSITES LTDActive - Proposal to Strike off- 09393024 - Incorporated on 16 January 2015 
- IRWIN AVIATION LIMITEDActive - Proposal to Strike off- 12080769 - Incorporated on 2 July 2019 
- IRWIN INVESTMENTS LTD- 13902261 - Incorporated on 8 February 2022 
- IRWIN EDITORIAL LIMITED- 13509780 - Incorporated on 14 July 2021 
- IRWIN SENIOR LIMITEDActive - Proposal to Strike off- 14528525 - Incorporated on 7 December 2022 
- IRWIN NEUROPSYCHOLOGY LIMITED- 16187546 - Incorporated on 16 January 2025 
- JACQUELINE SMITH 1665 LTDActive - Proposal to Strike off- 10073104 - Incorporated on 18 March 2016 
- CONNOR MACLEOD LIMITEDActive - Proposal to Strike off- SC245358 - Incorporated on 10 March 2003 
- KATRINA IRWIN LIMITEDActive - Proposal to Strike off- 10583676 - Incorporated on 25 January 2017 
- IRWIN MORGAN LIMITEDDisolved- 14684977 - Dissolved on 15 April 2025 
- IRWIN CONSULTING LIMITED- 15471782 - Incorporated on 7 February 2024 
- DAVID IRWIN LIMITED- 00840404 - Incorporated on 9 March 1965 
- IRWIN HOMES LIMITEDDissolved- 06838447 - Dissolved on 13 May 2014 
- LLOYD & IRWIN LIMITEDDissolved- 05860624 - Dissolved on 22 November 2011 
- IRWIN EDUCATION LIMITED- 07495077 - Incorporated on 17 January 2011 
- IRWIN CONSULTANCY LTDDissolved- 09547059 - Dissolved on 8 January 2019 
- IRWIN & JORDAN LIMITEDIn Administration- 06143221 - Incorporated on 7 March 2007 
- IRWIN PAVING LIMITEDActive - Proposal to Strike off- 04887067 - Incorporated on 4 September 2003