| Independent Timber Supplies Limited | Wholesale & retail | 2016 |
| Ingen Limited | Extraterritorial | 2006 |
| Inglewood Amenity Management Company Limited | Real estate | 2005 |
| Innocent Energy Ltd | Construction | 2010 |
| Insight Dynamics Limited | Health & social care | 2005 |
| Inspect South West Limited | Professional & scientific | 2023 |
| Inspire Construction (SE) Limited | Real estate | 2022 |
| Inspired Lines Limited | Professional & scientific | 2005 |
| Inst Logistics Ltd | Transport & logistics | 2017 |
| Intego Life Limited | Financial services | 2017 |
| Integrity Driver Training Ltd | Education | 2023 |
| Iris Resourcing Services Limited | Administrative & support | 2016 |
| Isight Therapies Limited | Health & social care | 2009 |
| ISL Coaching Ltd | Other services | 2023 |
| Iszod Ltd | Administrative & support | 2018 |
| J & S Realty Ltd | Real estate | 1998 |
| J Bibby Limited | Construction | 2015 |
| J C Lettings Limited | Real estate | 2013 |
| J Cottrell Railway Tester Ltd | Construction | 2020 |
| J R Ward Limited | Construction | 2008 |
| J W Plumbing and Heating (SW) Ltd | Construction | 2020 |
| J&S Commercials Limited | Transport & logistics | 2022 |
| J. V. LEE Electrical Limited | Construction | 2005 |
| J.C. Thompson (Stoneland Farm) Limited | Agriculture & fishing | 1964 |
| J.H. & J.L. Gibson Limited | Hospitality | 2008 |
| J28 Tackle and Bait Ltd | Wholesale & retail | 2025 |
| J3I Limited | Professional & scientific | 1999 |
| Jackson Walker Limited | Professional & scientific | 2008 |
| Jagged Edge Limited | Information & communication | 2016 |
| Jake Young Services Ltd | Arts & recreation | 2021 |
| Jalapinos Ltd | Hospitality | 2023 |
| James Loftus Construction Ltd | Construction | 2020 |
| James Loftus Groundworks Limited | Construction | 2025 |
| James Mason Limited | Wholesale & retail | 2002 |
| James Planning & Development Services Ltd | Professional & scientific | 2020 |
| James Pryce Tractors Limited | Wholesale & retail | 2011 |
| Jamic Properties Limited | Real estate | 2024 |
| Jansen UK EOT Limited | Professional & scientific | 2024 |
| Janus Gbac Limited | Manufacturing | 2014 |
| JB Autos (SW) Limited | Wholesale & retail | 2023 |
| Jbdevon Ltd | Wholesale & retail | 2026 |
| JBR Buildings Limited | Construction | 2019 |
| Jemima Wilmon Stokes Ltd | Arts & recreation | 2025 |
| Jennifer Jane Photography Limited | Professional & scientific | 2015 |
| Jenny Field Property Limited | Real estate | 2016 |
| Jfdi Print Services Ltd | Manufacturing | 2007 |
| JGS Forestry Ltd | Agriculture & fishing | 2024 |
| JH & GR Ison Limited | Professional & scientific | 2012 |
| JHD Automotive Limited | Professional & scientific | 2008 |
| JJ Mobiles Limited | Wholesale & retail | 2019 |
| JK Properties South West Limited | Real estate | 2019 |
| JKG (South West) Limited | Arts & recreation | 2016 |
| JLG Construction Services Ltd | Construction | 2016 |
| JM & CW Limited | Real estate | 2014 |
| Joanna North Adoption Limited | Health & social care | 2020 |
| Joanne Russell Limited | Health & social care | 2009 |
| John Heathcoat Trustee Company Limited | Professional & scientific | 2007 |
| John Kennedy Investment Limited | Real estate | 1949 |
| John Luffman Group Ltd. | Financial services | 2009 |
| John Luffman Trading Limited | Construction | 2001 |
| John Maxwell Limited | Information & communication | 2012 |
| Johnson Hawkins LLP | | 2016 |
| Jolly Vintner Limited | Wholesale & retail | 2004 |
| JRM Mechanical Engineering Ltd | Professional & scientific | 2023 |
| JSP Textile Solutions Ltd | Wholesale & retail | 2014 |
| Jtka Limited | Health & social care | 2013 |
| JTT Property Limited | Real estate | 2021 |
| Judo Services Limited | Education | 2024 |
| Jurston Farm Limited | Households | 2010 |
| K & C Denscombe Ltd | Agriculture & fishing | 2022 |
| K & D Roofing Specialists Limited | Construction | 2023 |
| K & G Carpenters Ltd | Construction | 2022 |
| K & J Greeting Cards Ltd | Wholesale & retail | 2019 |
| K a Mingo Livestock Limited | Transport & logistics | 2011 |
| K and T Tyres Ltd | Wholesale & retail | 2018 |
| K Ayre Building Limited | Construction | 2015 |
| K Campbell Consulting Ltd | Professional & scientific | 2019 |
| K J Milton Limited | Agriculture & fishing | 2015 |
| K M Carpentry & Building Services Limited | Construction | 2019 |
| K R Construction Contractors Ltd | Construction | 2025 |
| K4 Service Ltd | Construction | 2014 |
| KA2A Limited | Wholesale & retail | 2025 |
| Kaba Limited | Manufacturing | 1999 |
| KAP Engineering & Fabrication Limited | Manufacturing | 2010 |
| Katie's Kare Ltd | Health & social care | 2024 |
| Kayem Systems Ltd | Information & communication | 2024 |
| KDB Supply Chain Consultant Ltd | Professional & scientific | 2025 |
| KEK International Trading LLP | | 2024 |
| Kelly Legal Services Limited | Professional & scientific | 2013 |
| KEN White Signs Limited | Professional & scientific | 2002 |
| Kensington Court Management (Washfield) Co. Limited | Households | 2003 |
| Kenyon Clarke Financial Services Ltd | Financial services | 2010 |
| KEP Limited | Professional & scientific | 1986 |
| Keralakada Ltd | Wholesale & retail | 2023 |
| Kestrel Wildlife Consultants Limited | Professional & scientific | 2008 |
| Kevin Ford Ltd | Professional & scientific | 2014 |
| Keystone Farms Ltd | Agriculture & fishing | 2019 |
| Keystone Portfolio Limited | Financial services | 2011 |
| KG & MRS SA Middleton Limited | Construction | 2006 |
| Kids Holiday Heroes Ltd | Health & social care | 2023 |