- REID MACKELLAR LIMITED- SC224081 - Incorporated on 9 October 2001 
- MACKELLAR RACING LTD- 09982893 - Incorporated on 2 February 2016 
- DOUGLAS & STEWART CONTRACTING UK LIMITEDDisolved- 12201453 - Dissolved on 13 September 2022 
- STEWART DOUGLAS (THISTLE SERVICES) LTDActive - Proposal to Strike off- SC581882 - Incorporated on 17 November 2017 
- MACKELLAR SUB-SEA LTD- SC784931 - Incorporated on 4 October 2023 
- SUJIN MACKELLAR LIMITEDDisolved- 12859716 - Dissolved on 28 February 2023 
- D J MACKELLAR LIMITEDDisolved- 05058988 - Dissolved on 20 August 2024 
- MACKELLAR FABTEC LTDActive - Proposal to Strike off- SC499068 - Incorporated on 27 February 2015 
- MACKELLAR ARCHITECTURE LIMITEDDissolved- 03627731 - Dissolved on 5 May 2014 
- MACKELLAR ENGINEERING LTD- SC639388 - Incorporated on 20 August 2019 
- MACKELLAR BARNACK LTDActive - Proposal to Strike off- 09601639 - Incorporated on 20 May 2015 
- MACKELLAR HOLDINGS LTD- SC850257 - Incorporated on 28 May 2025 
- CARNOUSTIE REALISATIONS LIMITEDIn Administration/Administrative Receiver- SC438510 - Incorporated on 10 December 2012 
- STEWART JOHN MR- 72 CALEDONIA ROAD, KIRKCALDY, FIFE, SCOTLAND, KY2 5EP 
- GRANT MACKELLAR LTD- SC705167 - Incorporated on 28 July 2021 
- MACKELLAR SCHWERDT LLP- OC416635 - Incorporated on 29 March 2017 
- MACKELLAR MARINE LIMITEDActive - Proposal to Strike off- SC468351 - Incorporated on 27 January 2014 
- MACKELLAR CONSULT LIMITED- 07397949 - Incorporated on 6 October 2010 
- MACKELLARS- CALEDONIAN SUITE, ST ANDREWS HOUSE, 141 WEST NILE STREET, GLASGOW, LANARKSHIRE, G1 2RN 
- STEWART STEWART STEWART & STEWART LIMITEDDisolved- 12547095 - Dissolved on 14 May 2024