- CARTER HAYNES LIMITEDDisolved- 07140792 - Dissolved on 7 December 2021 
- FISHER & HAYNES LIMITED- 04682098 - Incorporated on 28 February 2003 
- HAYNES FURNISHERS LIMITED- 07800806 - Incorporated on 6 October 2011 
- HAYNES & RUSSELL LIMITEDDissolved- 07698289 - Dissolved on 9 May 2017 
- HAYNES ACCOUNTING LIMITED- 07923011 - Incorporated on 25 January 2012 
- WATSON HAYNES LIMITED- 00653673 - Incorporated on 23 March 1960 
- HAYNES INTERNATIONAL LTD- 01209891 - Incorporated on 29 April 1975 
- MORGAN HAYNES LIMITED- 06690011 - Incorporated on 5 September 2008 
- HAYNES HOUSE LIMITEDActive - Proposal to Strike off- 08276193 - Incorporated on 31 October 2012 
- HAROLD HAYNES LIMITED- 00526091 - Incorporated on 25 November 1953 
- HAYNES MEDICAL LIMITEDDisolved- 08843849 - Dissolved on 19 October 2021 
- HAYNES STUART LIMITED- 11642576 - Incorporated on 25 October 2018 
- HAYNES ASSOCIATES LTD.- 09705438 - Incorporated on 28 July 2015 
- GEOFF HAYNES LIMITED- 09420112 - Incorporated on 3 February 2015 
- HAYNES AUTOMOTIVE LTDDisolved- 10021129 - Dissolved on 28 June 2022 
- HAYNES CRANES LIMITEDActive - Proposal to Strike off- 10587182 - Incorporated on 27 January 2017 
- STEVEN HAYNES LIMITED- 11060749 - Incorporated on 13 November 2017 
- HAYNES PORTFOLIO LIMITED- 11119421 - Incorporated on 20 December 2017 
- HAYNES MASON LIMITEDDisolved- 11143307 - Dissolved on 21 January 2025 
- HAYNES PSYCHOLOGY LTD- 13275947 - Incorporated on 18 March 2021