| Janser UK Limited | Wholesale & retail | 1988 |
| Jarratt Ltd | Wholesale & retail | 2026 |
| Jason Pegg Limited | Arts & recreation | 2024 |
| Jasper Barton Ltd | Arts & recreation | 2023 |
| Jasper Wright Ltd | Real estate | 2026 |
| Java House Ltd | Financial services | 2020 |
| Jaybies Wholesale Ltd | Wholesale & retail | 2024 |
| JB Utilities Ltd | Administrative & support | 2017 |
| Jb's Fitness Hub Ltd | Arts & recreation | 2020 |
| JB18 Properties Ltd | Real estate | 2021 |
| JBM 365 Ltd | Transport & logistics | 2022 |
| JBS (Tiling Contractors) Limited | Construction | 1992 |
| JBS9 Property Limited | Real estate | 2025 |
| JC Events Stourbridge Ltd | Arts & recreation | 2014 |
| JC32 Properties Limited | Real estate | 2025 |
| JCR Media Ltd | Information & communication | 2023 |
| JCR Plumbing & Heating Limited | Administrative & support | 2009 |
| JD Hoskins Limited | Construction | 2025 |
| JD Services (Plant) Limited | Administrative & support | 2019 |
| JD25 Property Limited | Real estate | 2021 |
| JDD Furniture Ltd | Manufacturing | 2010 |
| JDM Installations Limited | Construction | 2008 |
| JDN Property Ltd | Real estate | 2023 |
| JDN Trades Ltd | Other services | 2023 |
| JDS2 Property Ltd | Real estate | 2024 |
| Jedics Holdings Limited | Financial services | 2025 |
| Jesp Engineering Limited | Professional & scientific | 1998 |
| JET Air Conditioning Ltd | Construction | 2005 |
| Jetset Couriers Ltd | Transport & logistics | 2021 |
| JF26 Cricket Limited | Arts & recreation | 2025 |
| JF26 Properties Limited | Real estate | 2023 |
| JFO Limited | Professional & scientific | 2026 |
| JGC Services Limited | Administrative & support | 2020 |
| JHP UK Services Limited | Other services | 2019 |
| JJE Consultancy Solutions Ltd | Information & communication | 2023 |
| JL Brigdale Ltd | Wholesale & retail | 2025 |
| Jlet Limited | Real estate | 2021 |
| JLJ21 Properties Limited | Real estate | 2025 |
| JLW2 Properties Ltd | Real estate | 2024 |
| JMB Global Ltd | Wholesale & retail | 2013 |
| JMB Innovations Ltd | Wholesale & retail | 2016 |
| JMC Accountants & Tax Advisers Limited | Professional & scientific | 2008 |
| JMC Holdings (Midlands) Limited | Financial services | 2019 |
| JML Haulage Ltd | Transport & logistics | 2019 |
| JML Transport Ltd | Transport & logistics | 2025 |
| JN Dancing Chef Ltd | Hospitality | 2024 |
| Joanna Carter Flowers Limited | Wholesale & retail | 2014 |
| Joaquin Properties Ltd | Real estate | 2025 |
| JOE Sbarra Properties Limited | Real estate | 2020 |
| JOE the Rockstar Limited | Arts & recreation | 2016 |
| John Bood Butchers Limited | Wholesale & retail | 2007 |
| John Downes (Garage) Limited | Real estate | 1999 |
| John Downes (Garages UK) Limited | Wholesale & retail | 2012 |
| John Henderson Dart Promotions Limited | Arts & recreation | 2012 |
| John Law Machinery Limited | Professional & scientific | 1980 |
| Johnstell Construction and Finisher Ltd | Construction | 2024 |
| Jomac Developments LLP | | 2025 |
| Jonathan's Kitchen Ltd | Hospitality | 2020 |
| Joseph & Sons Asian Groceries Ltd | Wholesale & retail | 2021 |
| Josh Rock Darts Limited | Arts & recreation | 2022 |
| Jotams Plumbing & Heating Ltd | Construction | 2021 |
| Joyce Software Services Limited | Information & communication | 2000 |
| Jozalia Limited | Real estate | 2023 |
| Jozefzoon Properties Limited | Real estate | 2020 |
| JP Brockmoor Limited | Hospitality | 2025 |
| Jpfc Properties Limited | Real estate | 2025 |
| JPM (Acquisitions) Limited | Financial services | 2010 |
| JPM (Directorships) Limited | Extraterritorial | 2004 |
| JPM (Insurance Management) Limited | Financial services | 1999 |
| JPM Group Limited | Financial services | 1999 |
| JR Aa&G Properties Limited | Real estate | 2024 |
| JR Executive Legal Solutions Limited | Administrative & support | 2025 |
| JRL Forklift Services Limited | Construction | 2016 |
| JRS Plumbing and Heating Midlands Ltd | Construction | 2024 |
| JS Barbers Ltd | Other services | 2018 |
| JS Seventeen Limited | Real estate | 2020 |
| JS10 Properties Limited | Real estate | 2025 |
| JSA Accountants Ltd | Professional & scientific | 2013 |
| JSA8 Properties Ltd | Real estate | 2024 |
| Jsiw Lighting Ltd | Professional & scientific | 2026 |
| JSS Homes Ltd | Real estate | 2023 |
| JT23 Properties Ltd | Real estate | 2024 |
| JTM Midlands Limited | Financial services | 2022 |
| Juice Gremlins Ltd | Wholesale & retail | 2017 |
| Julian Stafford Limited | Professional & scientific | 2023 |
| Julie Price & Co Limited | Financial services | 2001 |
| Jumbo Express (Freight) Limited | Transport & logistics | 2009 |
| June Barnett Properties Limited | Real estate | 2008 |
| Junernal Ltd | Administrative & support | 2016 |
| Just Modular Limited | Financial services | 2019 |
| Just Modular Services Limited | Extraterritorial | 2019 |
| Jutz Cutz 2 Limited | Other services | 2019 |
| Jutz Cutz 3 Limited | Other services | 2020 |
| Jutz Cutz Limited | Other services | 2014 |
| JW1 Properties Ltd | Real estate | 2024 |
| JW68 Limited | Arts & recreation | 2023 |
| JW68 Properties Limited | Real estate | 2023 |
| Jwss Ltd | Construction | 2026 |
| K & C Consulting Limited | Professional & scientific | 2023 |
| K & D Bespoke Sheds Ltd | Manufacturing | 2022 |