| Jard Holdings Ltd | Information & communication | 2024 |
| Jasmine Homes Ltd | Administrative & support | 2019 |
| JD Fleet Services Limited | Wholesale & retail | 2023 |
| Jecta Limited | Manufacturing | 1998 |
| Jegata Ltd | Health & social care | 2023 |
| Jessica Thomas Housekeeping Ltd. | Households | 2018 |
| Jetica Limited | Other services | 1998 |
| Jfaudio Ltd | Information & communication | 2016 |
| JK Consulting (Global) Ltd | Information & communication | 2025 |
| JM Auto Consultancy Ltd | Professional & scientific | 2025 |
| JMC Fabrications and Pipework Limited | Administrative & support | 2014 |
| JMW Global Ltd | Wholesale & retail | 2010 |
| Jo's Fast Food Ltd | Hospitality | 2022 |
| Jogeem Holdings Limited | Financial services | 2026 |
| John Giddings (Farms) Limited | Agriculture & fishing | 1973 |
| John Woodhouse Heating Limited | Construction | 2014 |
| Jonathan Peters Play Limited | Professional & scientific | 2018 |
| Jongen Supply Chain Consultancy Ltd | Professional & scientific | 2024 |
| JR 25 Controls Limited | Construction | 2016 |
| JR Homes (SW) Limited | Construction | 2024 |
| JS Training Consultancy Limited | Professional & scientific | 2018 |
| JSF Services (South West) Ltd | Other services | 2022 |
| JTF Limited | Professional & scientific | 2024 |
| JTS Automation Limited | Professional & scientific | 2010 |
| K N & P Limited | Education | 2023 |
| K R Ventures Limited | Information & communication | 2015 |
| Kadir Catering Ltd | Hospitality | 2022 |
| Kapan Melksham Ltd | Wholesale & retail | 2025 |
| Kate Johnson Aesthetics and Beauty Ltd | Other services | 2025 |
| Kathryn Dugdale Counselling & Holistics Ltd | Other services | 2021 |
| Kaydon Group Ltd | Agriculture & fishing | 2023 |
| Kelana Ltd | Transport & logistics | 2023 |
| Kennick Building Contractors Limited | Construction | 2013 |
| Kevan Family LLP | | 2013 |
| Keystone Security Group Ltd | Administrative & support | 2026 |
| Kinded Limited | Health & social care | 2021 |
| Kings Home Improvements Ltd | Construction | 2008 |
| Kingsbury M.O.T Centre Limited | Wholesale & retail | 2025 |
| Kipa Tree Consulting Ltd | Professional & scientific | 2024 |
| Kirkman Bespoke Woodworking Ltd | Manufacturing | 2026 |
| Kirkuk Grill House Ltd | Hospitality | 2024 |
| Kitchen Interiors (UK) Ltd | Construction | 2002 |
| KLS Automotive Ltd | Wholesale & retail | 2025 |
| Knorr-Bremse Rail Systems (UK) Limited | Manufacturing | 2000 |
| Kristek (Holdings) Limited | Professional & scientific | 1995 |
| Kristek Precision Limited | Manufacturing | 1986 |
| KS Plumbing & Bathrooms Ltd | Construction | 2026 |
| L & C Scaffolding Limited | Construction | 2018 |
| L S B Retail Ltd | Wholesale & retail | 2022 |
| L W Roofing Limited | Construction | 2018 |
| L&A Nails Ltd | Other services | 2022 |
| Larkwood Management Services Limited | Real estate | 1997 |
| Lashesbyshianna Ltd | Other services | 2025 |
| Launch With Love Ltd | Information & communication | 2022 |
| Law Plumbing & Heating Ltd | Construction | 2018 |
| LBL Midlands Limited | Wholesale & retail | 2011 |
| LCP Fire Protection Ltd | Construction | 2024 |
| Leafield Marine Limited | Manufacturing | 2006 |
| Leclercq Ltd | Professional & scientific | 2023 |
| LEE Hvca Management Ltd | Administrative & support | 2016 |
| Lemms Ltd | Hospitality | 2025 |
| LGP Investments Ltd | Real estate | 2025 |
| Lifecraft Development Limited | Professional & scientific | 2000 |
| Lionheart Law Limited | Professional & scientific | 2025 |
| Lionhearts Consultancy Ltd | Health & social care | 2012 |
| Little Sparks Tutoring Ltd | Education | 2025 |
| Little Thornham Holidays Ltd | Hospitality | 2023 |
| LKJ Aesthetics & PMU Ltd | Other services | 2019 |
| Lloyd Winter Partners Ltd | Real estate | 2025 |
| Lofti Bath Bombs Limited | Wholesale & retail | 2019 |
| Longleaze Lane Limited | Other services | 2011 |
| Lordlevisten Plumbing Limited | Construction | 2025 |
| Lost Valley Ltd | Real estate | 2018 |
| Lovejoys Wholesale Ltd | Wholesale & retail | 2011 |
| Loyal Logistics Limited | Transport & logistics | 2024 |
| LR9 Ltd | Wholesale & retail | 2026 |
| LSH Civil Engineering Solutions Ltd | Professional & scientific | 2026 |
| Lukas & Ayliffe Limited | Construction | 1995 |
| Luma Eco-Flex Lighting Limited | Wholesale & retail | 2026 |
| Lumos Energy Ltd | Construction | 2015 |
| LWB Management Ltd | Real estate | 2019 |
| LWB Property Ltd | Real estate | 2019 |
| LWR Electrical Ltd | Construction | 2014 |
| LZ Honey Upholstery Ltd | Real estate | 2024 |
| M J Elmes Electrical Services Ltd | Construction | 2012 |
| M L King Electrical Limited | Construction | 2014 |
| M&J Asbestos Specialists Ltd | Water & waste | 2025 |
| M&P Tanning Salons Empire Limited | Other services | 2021 |
| M.A.A.C.Currier Ltd | Transport & logistics | 2022 |
| M4 Lock & Safe Limited | Administrative & support | 2013 |
| MA Avad & Sons Ltd | Real estate | 2024 |
| MAC Village Phone Repair Ltd | Other services | 2026 |
| MAC Village.M Ltd | Wholesale & retail | 2022 |
| Macey's Architectural Design & Development Ltd | Professional & scientific | 2024 |
| MAD Monkey Media Ltd | Information & communication | 2025 |
| Magicads Ltd | Information & communication | 2021 |
| Magnate Consultancy Limited | Information & communication | 1993 |
| Magpie Traders Limited | Wholesale & retail | 2012 |
| MAID2CLEAN North Staffs Limited | Administrative & support | 2011 |
| Majo Investment Ltd | Public administration | 2019 |