| Jody Kirton Limited | Construction | 2022 |
| JOE Clarke Bricklaying & Building Ltd | Administrative & support | 2017 |
| JOE Conlin Consulting Ltd | Professional & scientific | 2022 |
| Jofish Limited | Administrative & support | 2002 |
| Jogpal Limited | Hospitality | 2013 |
| Johal Property Limited | Real estate | 2006 |
| John Atkins Cycles (Leamington Spa) Ltd. | Wholesale & retail | 1996 |
| John Collins Estimating Limited | Administrative & support | 2018 |
| John Onions Solicitors Limited | Professional & scientific | 2014 |
| John S Hall Limited | Professional & scientific | 2015 |
| John Walker Design Limited | Administrative & support | 2010 |
| Johnchukwu Properties Ltd | Real estate | 2025 |
| Johnson Aviation Solutions Limited | Transport & logistics | 2026 |
| Johnson Family Homes Limited | Real estate | 2025 |
| Jointak Labels UK Limited | Manufacturing | 2020 |
| JON Price Financial Planning Ltd | Financial services | 2026 |
| Jon's Construction and Carpentry Services Ltd | Construction | 2017 |
| Jonathan James Developments Limited | Construction | 2015 |
| Joose Moose Ltd | Manufacturing | 2025 |
| Jora Consulting Limited | Professional & scientific | 2023 |
| Jordan Builders Ltd | Construction | 2004 |
| Joshua Mcguinness Limited | Administrative & support | 2019 |
| Joyful Insights Ltd | Professional & scientific | 2024 |
| Joyful Living NOW Enterprises Ltd | Professional & scientific | 2024 |
| JPK Ukgh Ltd | Transport & logistics | 2026 |
| Jpmad Properties Ltd | Real estate | 2025 |
| JPW Property Limited | Real estate | 2018 |
| JPW2013 Limited | Administrative & support | 2013 |
| JR Gill Investments Limited | Real estate | 2012 |
| JR Sports Massage Therapy Limited | Other services | 2026 |
| JRD Property Maintenance Ltd | Construction | 2020 |
| JRG Construction Limited | Construction | 2009 |
| JRL Contracts Limited | Professional & scientific | 2020 |
| JRP Holdings Ltd | Construction | 2021 |
| JRP Property Development Ltd | Real estate | 2020 |
| JS Logistics Consultancy Limited | Professional & scientific | 2026 |
| JS Property Services Limited | Real estate | 2022 |
| JS Sahota Services Ltd | Transport & logistics | 2022 |
| JS Trading (Leamington Spa) Ltd | Real estate | 2005 |
| JSL (Trevenson) Limited | Real estate | 2015 |
| JSV Autos Ltd | Manufacturing | 2026 |
| JTS KBB Ltd | Professional & scientific | 2019 |
| Jubilee Gardens Property Management Company Limited | Administrative & support | 2012 |
| Julie Bell Ltd | Professional & scientific | 2012 |
| Jumpxl Limited | Professional & scientific | 2012 |
| Jumpxl Ventures Limited | Professional & scientific | 2012 |
| Junerain Ltd | Other services | 2006 |
| Junerain Travels Ltd | Administrative & support | 2025 |
| Just Anything CC Ltd | Manufacturing | 2009 |
| Just Build UP Limited | Education | 2024 |
| Just Build UP Media Limited | Information & communication | 2026 |
| Just Build UP Partnerships Ltd | Construction | 2025 |
| Just Mind Ltd | Health & social care | 2018 |
| Just Prime Ltd | Real estate | 2020 |
| Just Properties CC Limited | Construction | 2025 |
| Just SAY NAY Limited | Arts & recreation | 2020 |
| JW Property Maintenance & Building Services Ltd | Construction | 2015 |
| JWR Pubs Limited | Hospitality | 2024 |
| Jzee Foods Ltd | Extraterritorial | 2019 |
| K & H Productions Limited | Information & communication | 2024 |
| K & L Aesthetics Limited | Other services | 2023 |
| K & N Portfolio Limited | Real estate | 2018 |
| K & S Lettings Limited | Households | 2022 |
| K & S Services (Leicester) Limited | Administrative & support | 2007 |
| K Partridge Holdings Limited | Financial services | 2019 |
| K R Modelling Services Limited | Administrative & support | 2009 |
| K Reardan Family Law Consultancy Ltd | Professional & scientific | 2024 |
| K Shaw Property Services Limited | Households | 2015 |
| K Warriner Limited | Education | 2011 |
| K&C Caffe's Ltd | Hospitality | 2025 |
| K&H Property Company Limited | Real estate | 2021 |
| K&M Halal Food Ltd | Wholesale & retail | 2024 |
| K-San Limited | Information & communication | 2009 |
| K.B Construction (Midlands) Ltd | Construction | 2021 |
| K.Barber Limited | Arts & recreation | 2021 |
| K4 IP Ltd | Professional & scientific | 2025 |
| K9 Anytime Training Limited | Other services | 2019 |
| KA Health Enterprise Ltd | Health & social care | 2024 |
| KAD Healthcare Ltd | Health & social care | 2025 |
| Kaira Homes Ltd | Real estate | 2025 |
| Kairo Data Intelligence Limited | Information & communication | 2025 |
| Kairos Consultoria Y Formacion Ltd | Education | 2024 |
| Kairosnow Ltd | Professional & scientific | 2025 |
| Kaitec Limited | Information & communication | 2025 |
| Kakabashe Limited | Hospitality | 2025 |
| Kalayaan Solutions Ltd | Administrative & support | 2025 |
| Kalza Ltd | Wholesale & retail | 2022 |
| KAM Auto Engineering Limited | Professional & scientific | 2024 |
| Kamakura Properties Limited | Real estate | 2012 |
| Kamirage Limited | Information & communication | 2025 |
| Kandy Apparel UK Limited | Wholesale & retail | 2024 |
| Kanecom Ltd | Wholesale & retail | 2025 |
| Karack Limited | Real estate | 2013 |
| Karate & Dance FED Ltd | Arts & recreation | 2026 |
| Kare Knowledge Learning and Development Ltd | Education | 2025 |
| Karen Ellis Consultancy Limited | Professional & scientific | 2025 |
| Karen Mccormick Associates Limited | Administrative & support | 2015 |
| Karma Yoga Limited | Arts & recreation | 2017 |
| Karpet Kingdom (Leamington) Limited | Wholesale & retail | 2013 |
| Kasai Technologies Ltd | Professional & scientific | 2017 |