| JJT Electrical Limited | Construction | 2012 |
| JK Construction Consultancy Ltd | Professional & scientific | 2014 |
| JK Road Markings Ltd | Construction | 2003 |
| Jkdev Foods Limited | Hospitality | 2025 |
| JKG Carpets Ltd | Wholesale & retail | 2008 |
| JL Maritime Services Limited | Other services | 2019 |
| JL Plastics Limited | Professional & scientific | 2008 |
| JL Prescribing Ltd | Health & social care | 2025 |
| Jlbr Consultants Ltd | Administrative & support | 2024 |
| JLM Construction Services Ltd | Construction | 2016 |
| JLM Garden Design Limited | Administrative & support | 2016 |
| JLO Electrical Ltd | Construction | 2022 |
| JLQ Management Ltd | Information & communication | 2019 |
| Jlsrp Holdings Ltd | Real estate | 2022 |
| JM Access Ltd | Construction | 2023 |
| JM Flooring NW Ltd | Wholesale & retail | 2024 |
| JM Holdings Group Ltd | Financial services | 2025 |
| JM IT Services and Contracts Limited | Information & communication | 2021 |
| JM Mobile Tech Ltd | Wholesale & retail | 2025 |
| JM Rope Services Limited | Other services | 2013 |
| JMB Specialised Services Limited | Professional & scientific | 2018 |
| Jmb&G Limited | Other services | 2014 |
| JMC Fylde Property Management Ltd | Households | 2026 |
| JMC Inspection NW Ltd | Professional & scientific | 2023 |
| Jmcall Landscaping Limited | Other services | 2021 |
| JMD Business Ltd | Real estate | 2025 |
| JMD Housing Ltd | Real estate | 2022 |
| JMD X2 Ltd | Wholesale & retail | 2023 |
| JML Building & Construction Services Ltd | Construction | 2020 |
| JMY Properties Limited | Real estate | 2016 |
| JNB Accountancy Limited | Professional & scientific | 2014 |
| Jncs Inc Ltd | Construction | 2023 |
| JNF Builders Ltd | Construction | 2025 |
| JNM Holdings Ltd | Financial services | 2020 |
| Jnshaw Ltd | Construction | 2021 |
| JO Alice Group Ltd | Professional & scientific | 2021 |
| JO Diep Limited | Professional & scientific | 2012 |
| Joanne M Laffin Financial Planning Ltd | Financial services | 2020 |
| Jobs, Friends & Houses Community Interest Company | Construction | 2014 |
| JOE & Tins Ltd | Wholesale & retail | 2024 |
| JOE Barlow Vape Store Limited | Wholesale & retail | 2023 |
| Joel Lewis Cars Limited | Extraterritorial | 2018 |
| Joeysons Ltd | Wholesale & retail | 2022 |
| Johanna Carter Coaching, Mentoring and Training Limited | Administrative & support | 2023 |
| John & C.Lowes,Limited | Professional & scientific | 1960 |
| John Boyle Consulting Ltd | Professional & scientific | 2013 |
| John Crookall Aviation Ltd | Manufacturing | 2024 |
| John Duffies Ltd | Wholesale & retail | 2025 |
| John Earnshaw Holdings Ltd | Real estate | 2017 |
| John Earnshaw Independent Financial Advisers Limited | Financial services | 2003 |
| John Frederick Duckworth Ltd | Extraterritorial | 2024 |
| John Jackson (Bacon) Limited | Wholesale & retail | 1972 |
| John Morrison Limited | Professional & scientific | 2018 |
| John Nicol Fabrications Ltd | Manufacturing | 2022 |
| John the Fish Limited | Wholesale & retail | 2003 |
| John Turner Aviation Consultancy Ltd | Professional & scientific | 2010 |
| Johns Friary Limited | Hospitality | 2022 |
| Johnson Empire Ltd | Hospitality | 2021 |
| Johnson G.B. Limited | Professional & scientific | 1984 |
| Johnston Consulting Engineers Limited | Construction | 2011 |
| Jolly Bars Limited | Hospitality | 2025 |
| JON Conway Limited | Arts & recreation | 2009 |
| JON Kelly Plastering Contractors Limited | Construction | 2015 |
| Jonathan Holt Ltd | Transport & logistics | 2024 |
| Jonathan M Daniels Limited | Information & communication | 2011 |
| Jonathan Nolan Ltd | Administrative & support | 2019 |
| Jones Innovation Group Limited | Financial services | 2026 |
| Jones Joinery and Builders Limited | Construction | 2024 |
| Jones the PUB Limited | Hospitality | 2012 |
| Jones's Garage Ltd | Wholesale & retail | 2009 |
| Jonmac Mobile Limited | Wholesale & retail | 2023 |
| Jonny Sumner Scaffolding Services Limited | Construction | 2017 |
| Jonnys Barbers Ltd | Other services | 2022 |
| Jonsar Properties Ltd | Real estate | 2021 |
| Jood Transport Ltd | Transport & logistics | 2019 |
| JOR 1 Ltd | Real estate | 2025 |
| Jordans Glass Services Limited | Manufacturing | 2019 |
| Jorde Ltd | Wholesale & retail | 2021 |
| Josbro Investments Limited | Real estate | 2023 |
| Joseph Boniface Architects Ltd | Professional & scientific | 2010 |
| Joseph Fielding Properties (Blackpool) Limited | Construction | 1946 |
| Joseph Louise Properties Ltd | Real estate | 2018 |
| Joseph Reilly Ltd | Information & communication | 2020 |
| Josephmoly Limited | Health & social care | 2025 |
| Joshuajack Ltd | Real estate | 2020 |
| Joules Energy Efficiency Services Ltd | Wholesale & retail | 2025 |
| Joyasoft Consulting Limited | Information & communication | 2012 |
| Joëlle NW Ltd | Professional & scientific | 2025 |
| JP Hamilton Limited | Construction | 2018 |
| JPB Property Limited | Real estate | 2008 |
| JPG (UK) Limited | Professional & scientific | 1998 |
| JPH Offshore Services Limited | Transport & logistics | 2015 |
| JPK Consulting Limited | Other services | 2013 |
| JPM Management Consultancy Ltd | Information & communication | 2021 |
| JPM Smart Repair’S Ltd | Wholesale & retail | 2026 |
| JR & D Sillis Ltd | Manufacturing | 2002 |
| JR NDT Inspection Ltd | Manufacturing | 2013 |
| JR Roofing Lancs Limited | Construction | 2017 |
| JR Solutions Services Limited | Construction | 2022 |
| Jr-Pr Holdings Ltd | Financial services | 2023 |