| JB Concept Communications Ltd | Construction | 2016 |
| JB Heating Plumbing and Electrical Ltd | Construction | 2018 |
| JC West Midlands Pubs Limited | Hospitality | 2024 |
| JCD Cars Limited | Wholesale & retail | 2010 |
| Jcdc Home Supplies Limited | Wholesale & retail | 2026 |
| JDM (Whitehouse) Investments Limited | Financial services | 2018 |
| JER Electrical Services Ltd | Construction | 2024 |
| Jesp Conjugal Ltd | Real estate | 2020 |
| JET Plumbing and Heating Services Ltd | Construction | 2019 |
| Jewkes Consulting Limited | Professional & scientific | 2011 |
| JFS Recruit Limited | Administrative & support | 2025 |
| JG Foods EOT Limited | Financial services | 2025 |
| JG Foods Limited | Wholesale & retail | 2012 |
| JGK Properties Ltd | Financial services | 2022 |
| JHD Fire Protection Contractors Limited | Public administration | 2020 |
| JHD Partnership Housing Limited | Construction | 2019 |
| JHD Solutions Limited | Agriculture & fishing | 2013 |
| JI & Sons Properties Limited | Real estate | 2024 |
| Jirehuk Limited | Wholesale & retail | 2006 |
| JJF Paving Limited | Administrative & support | 2019 |
| Jjnplnt Ecommerce Ltd | Wholesale & retail | 2023 |
| JJS Sports Coaching Ltd | Education | 2025 |
| Jkpubmanagement Ltd | Hospitality | 2025 |
| JL Tennis Limited | Arts & recreation | 2011 |
| JLB Design Services Ltd | Professional & scientific | 2021 |
| Jlhmcp (Holdings) Ltd | Financial services | 2025 |
| JLP Motors Ltd | Wholesale & retail | 2025 |
| JLT Equine Ltd | Agriculture & fishing | 2020 |
| JLT Utilities Ltd | Construction | 2022 |
| JLW (Surfacing) Ltd | Construction | 2016 |
| JM Bramall Limited | Financial services | 2018 |
| JM Plumbing & Domestic Services Ltd | Construction | 2017 |
| JMA Decor Ltd | Construction | 2023 |
| JN Electrical & Renovations Ltd | Construction | 2024 |
| JND Management Ltd | Professional & scientific | 2022 |
| JNS Utilities Ltd | Construction | 2023 |
| Jodi LEE Photography Ltd | Professional & scientific | 2022 |
| John Toogood Upholstery Limited | Other services | 2025 |
| Johnsons (Midlands) Properties Limited | Real estate | 2025 |
| Joined UP Carpentry Ltd | Manufacturing | 2018 |
| Jointmedica Limited | Manufacturing | 2000 |
| JON & Sam's Cafe Bar Ltd | Hospitality | 2023 |
| JON Kevan Limited | Other services | 2002 |
| JP Alliance Properties Ltd | Financial services | 2016 |
| JP Berks Limited | Real estate | 2022 |
| JPA Financial Services Limited | Other services | 2009 |
| JPB Restaurants Ltd | Hospitality | 2021 |
| JPC Cancelo Limited | Administrative & support | 2020 |
| Jplp Consultancy Limited | Professional & scientific | 2008 |
| Jpmc Properties Limited | Real estate | 2018 |
| JRC Industrials Ltd | Administrative & support | 2023 |
| JRC Travel Ltd | Administrative & support | 2026 |
| JRP Plastering Limited | Construction | 2024 |
| JS and TM Smith Services Ltd | Hospitality | 2020 |
| JT Pre-Training and Schooling Ltd | Agriculture & fishing | 2026 |
| Jubilee Fireworks Limited | Professional & scientific | 1994 |
| Judsons Fruit and VEG Limited | Wholesale & retail | 2022 |
| Juicy Creams Ltd | Wholesale & retail | 2023 |
| Junction Road Trading Estate Ltd | Real estate | 2023 |
| Jupiter Clear-Away Services Limited | Water & waste | 2023 |
| Just Press Print Limited | Administrative & support | 2017 |
| Jwebdesign Ltd | Professional & scientific | 2025 |
| K J E Financial Ltd | Administrative & support | 2016 |
| K Pearson Building Services Ltd | Construction | 2010 |
| K'Ford Auto Parts Ltd | Wholesale & retail | 2014 |
| K1 Kickboxing GB Ltd | Arts & recreation | 2023 |
| K1GB Ltd | Arts & recreation | 2023 |
| Kallenhard Limited | Financial services | 2024 |
| Kalra Investments Limited | Extraterritorial | 2008 |
| Kapital Limited | Wholesale & retail | 2019 |
| Karen Stone Consultancy Limited | Administrative & support | 2010 |
| Karma Clothing Ltd | Wholesale & retail | 2024 |
| Kate Dyoss Limited | Public administration | 2026 |
| KBC KW Ltd | Other services | 2018 |
| Kcbo Limited | Wholesale & retail | 2025 |
| Kdpengineering Limited | Professional & scientific | 2025 |
| KE Electrical Limited | Construction | 2022 |
| KE Solar Limited | Construction | 2022 |
| KEE 6 Investments Ltd | Real estate | 2020 |
| KEE Engineering Limited | Manufacturing | 2006 |
| KEE Solutions Ltd | Manufacturing | 2025 |
| Kennametal Logistics UK Limited | Transport & logistics | 2005 |
| Kennametal Manufacturing UK Limited | Manufacturing | 2005 |
| Kennametal UK Limited | Manufacturing | 1997 |
| Kesan Integrated Controls Ltd | Professional & scientific | 2020 |
| Keys of Freedom Limited | Real estate | 2022 |
| KF Lean Solutions Ltd | Professional & scientific | 2024 |
| Kford Pizza 5S Limited | Hospitality | 2026 |
| Kford Tutoring Ltd | Education | 2026 |
| Kford Tyres (Gornal) Ltd | Extraterritorial | 2015 |
| Kford Tyres Ltd | Manufacturing | 2012 |
| Kford Vehicle Deliveries Limited | Transport & logistics | 2012 |
| Khaya Buildings Ltd | Financial services | 2021 |
| KHC Real Estate Services Limited | Real estate | 2025 |
| Kilo Limited | Wholesale & retail | 2003 |
| Kindridge BID Solutions LLP | | 2024 |
| Kinfayre Property Co. Ltd | Real estate | 2019 |
| Kinfayre Restaurant Co. Ltd | Hospitality | 2019 |
| Kingsford Brickwork Limited | Construction | 2021 |
| Kingsley Consulting (Kingswinford) Ltd | Financial services | 2018 |