| JJ Hill Publishing Limited | Information & communication | 2024 |
| JJF Consulting Partners Limited | Professional & scientific | 2024 |
| JL Associates Ltd | Professional & scientific | 2010 |
| JM Garage Doors Ltd | Construction | 2025 |
| Jmdyer Limited | Health & social care | 2020 |
| Jmfe Limited | Professional & scientific | 2016 |
| Jmmedical Ltd | Professional & scientific | 2021 |
| JMP Fitness Promotions Limited | Administrative & support | 2019 |
| Jmra Holdings Limited | Administrative & support | 2017 |
| Jmra Properties Limited | Financial services | 2023 |
| JMT Capital Limited | Administrative & support | 2012 |
| JNC (Holdings) Limited | Financial services | 2016 |
| JNC UK Consulting Limited | Information & communication | 2017 |
| JNV Tree Surgeons Ltd | Administrative & support | 2022 |
| Jobson Property Limited | Real estate | 2017 |
| JOE Ashton Holdings Limited | Financial services | 2025 |
| John Bayliss Plumbing & Heating Limited | Construction | 2018 |
| John Dowty Limited | Arts & recreation | 1953 |
| John Gray (Stone & Lime) Limited | | 1983 |
| John Keel and Partners LLP | | 2015 |
| Johnson Commercial Property Limited | Households | 2023 |
| Johnson Probart & Co Limited | Construction | 2001 |
| Jojay (Droitwich) Limited | Construction | 2023 |
| Jojay (Ledbury) Limited | Construction | 2024 |
| Jojay Limited | Construction | 2009 |
| Jonathan Eaton Limited | Health & social care | 2012 |
| Jonathan Sproule Developments LLP | | 2018 |
| Josh Bloomer Film Services Limited | Information & communication | 2019 |
| Josl Developments Limited | Real estate | 2026 |
| Jotul (UK) Limited | Wholesale & retail | 1999 |
| Journal of CRR Ltd | Information & communication | 2022 |
| JPL Architectural Design Ltd | Professional & scientific | 2009 |
| JPS Investment Group Ltd | Real estate | 2023 |
| JRB Advisers Limited | Financial services | 2017 |
| JRM Risk Management Limited | Professional & scientific | 2019 |
| JRR Electrical Ltd | Construction | 2024 |
| JRW Heating and Plumbing Services Limited | Construction | 2007 |
| JS Transport Solutions Ltd | Professional & scientific | 2023 |
| JSF Services Limited | Information & communication | 2009 |
| Jsnc Hair Limited | Other services | 2026 |
| JTM Consult Ltd | Information & communication | 2021 |
| Jubileepearl Ltd | Transport & logistics | 2019 |
| Jujhar Private Ltd | Transport & logistics | 2026 |
| Jumbo Stud Partitions Ltd | Construction | 2022 |
| Just Build IT (Worcester) Ltd | Construction | 2016 |
| Just Menus Limited | Manufacturing | 2012 |
| Just the Answer Limited | Information & communication | 2003 |
| JW Removals Limited | Administrative & support | 2022 |
| JYW Phoenix Limited | Financial services | 2018 |
| K J Consulting Ltd | Professional & scientific | 2021 |
| K Newbold Ltd | Health & social care | 2017 |
| K V Valets Ltd | Administrative & support | 2025 |
| K&B Operations Ltd | Professional & scientific | 2020 |
| K&T Consultants Ltd | Professional & scientific | 2025 |
| K-D Medical Services Ltd | Health & social care | 2023 |
| K.B. & Sons Wholesale Ltd | Wholesale & retail | 2025 |
| K.B. Vape Pens Ltd | Wholesale & retail | 2024 |
| K.C.G. Installations Limited | Administrative & support | 2005 |
| K.K. Construction Engineering Limited | Construction | 2012 |
| KAD Holdings Limited | Administrative & support | 2018 |
| Kage IT Consultants Ltd | Information & communication | 2022 |
| Kakasev Property Services Limited | Real estate | 2021 |
| KAM Social Care Ltd | Health & social care | 2025 |
| Kangaroo Pouch Limited | Education | 2011 |
| Karelia Limited | Real estate | 2019 |
| Kasabourne Ltd | Construction | 2024 |
| Kasper Property Investments Limited | Real estate | 2025 |
| Kate Evans Coaching Ltd | Other services | 2020 |
| Kate Shrubb Holdings Limited | Financial services | 2011 |
| Kate's Dresses Ltd | Wholesale & retail | 2024 |
| Katie Helliwell Limited | Other services | 2020 |
| KAY & KAM Property Investments Limited | Real estate | 2016 |
| Kazam Retail Limited | Wholesale & retail | 2010 |
| KC Lifestyle Properties Ltd | Real estate | 2023 |
| KD Nail Studio Ltd | Other services | 2025 |
| Keens ELM Property Investments Limited | Real estate | 2018 |
| Keentoclean Ltd | Administrative & support | 2021 |
| Keep Attacking Limited | Administrative & support | 2013 |
| Kelbie Engineering Limited | Administrative & support | 2013 |
| Kelbie Holdings Limited | Financial services | 2022 |
| Kelbie Industries Limited | Administrative & support | 2024 |
| Kelpack Hire Limited | Administrative & support | 2009 |
| KEM Technical Services Limited | Administrative & support | 2018 |
| Kenmar Residents Management Company Limited | Real estate | 2021 |
| Kenneth Charles International Limited | Financial services | 2022 |
| Kents (U.K.) Limited | Professional & scientific | 2001 |
| Kepir Ltd | Hospitality | 2024 |
| Kerensky Limited | Administrative & support | 2026 |
| Keval Enterprises Ltd | Information & communication | 2016 |
| Kevin Hancox Limited | Construction | 2009 |
| KFV Solutions Ltd | Construction | 2011 |
| Khalsa Trade Ltd | Wholesale & retail | 2020 |
| Kidderminster MOT Ltd | Wholesale & retail | 2020 |
| Kido Education Limited | Information & communication | 2019 |
| Kido Nannies Limited | Health & social care | 2019 |
| Kido One Limited | Education | 2019 |
| Kido Schools UK Limited | Health & social care | 2016 |
| Kids F1RST Ltd | Health & social care | 2021 |
| Killernan Limited | Wholesale & retail | 2007 |
| Kingsbridge Homes Limited | Real estate | 2020 |