| JK Dhaliwal Construction Ltd | Construction | 2021 |
| JK Hudson Services Ltd | Construction | 2021 |
| JK Legal Services Ltd | Professional & scientific | 2022 |
| JK Machine & Model Limited | Manufacturing | 2009 |
| JK Martt Ltd | Wholesale & retail | 2025 |
| JK Real Estate Holdings Limited | Real estate | 2025 |
| JK Technologies CIC | Information & communication | 2025 |
| Jkar Services Limited | Construction | 2025 |
| JKD Digital Limited | Information & communication | 2021 |
| JKH Commercials Limited | Real estate | 2022 |
| JKM Dental Therapy Ltd | Health & social care | 2026 |
| JKM Supported Living Ltd | Health & social care | 2024 |
| JKN Healthcare Limited | Health & social care | 2021 |
| JKN Transport Ltd | Transport & logistics | 2020 |
| JKO & Co Consultancy Ltd | Professional & scientific | 2024 |
| JKP Property Holdings Limited | Financial services | 2021 |
| JKS Property Investments Ltd | Real estate | 2025 |
| Jksk Properties Ltd | Real estate | 2026 |
| JKU Holdings Limited | Financial services | 2023 |
| JL Drinks Ltd | Wholesale & retail | 2019 |
| JL GAS and Plumbing Ltd | Construction | 2025 |
| JL Homes & Investment Ltd | Real estate | 2026 |
| JL Safetyeye Solutions Ltd | Professional & scientific | 2025 |
| JLB Precision Engineering Ltd | Professional & scientific | 2024 |
| JLC Holdings Limited | Real estate | 2018 |
| Jlij Consultants Ltd | Information & communication | 2019 |
| JLM Project Services Ltd | Information & communication | 2025 |
| JLS 4 Ltd | Construction | 2025 |
| JLU Properties Limited | Real estate | 2020 |
| JM & KM Gifts Limited | Wholesale & retail | 2024 |
| JM Building & Construction Service Company Ltd | Extraterritorial | 2023 |
| JM Butler Electrical Ltd | Manufacturing | 2013 |
| JM Convenience Ltd | Wholesale & retail | 2018 |
| JM Events & Enterprise Limited | Wholesale & retail | 2024 |
| JM Generation Limited | Administrative & support | 2017 |
| JM Studies Ltd | Information & communication | 2024 |
| JM UK Properties Ltd | Real estate | 2020 |
| JMB Smart Solution Limited | Construction | 2018 |
| JMC Property Group Ltd | Hospitality | 2019 |
| JMD Estates Ltd | Real estate | 2025 |
| JMD Store Ltd | Wholesale & retail | 2024 |
| JME Property Holdings Limited | Real estate | 2023 |
| Jminvestmentsgroup Ltd | Construction | 2024 |
| JML Solutions Limited | Professional & scientific | 2007 |
| JML UK Property Ltd | Real estate | 2025 |
| Jmlongeaton Ltd | Construction | 2024 |
| JMP Wilcox & Co Limited | Wholesale & retail | 2000 |
| JMR Fitness Limited | Arts & recreation | 2017 |
| JMR Holdings Limited | Financial services | 2018 |
| JMT Property Investments Limited | Real estate | 2023 |
| JMW Aesthetics Ltd | Other services | 2026 |
| JN Solicitors Ltd | Professional & scientific | 2026 |
| JND Developers Ltd | Construction | 2026 |
| JNK Tower Ltd | Real estate | 2026 |
| JNM Homes Limited | Real estate | 2015 |
| Jnpk Limited | Transport & logistics | 2019 |
| JO MAE Ltd | Wholesale & retail | 2024 |
| Joan L'Lanziva Healthcare Services Limited | Health & social care | 2022 |
| JOB Change | Other services | 1988 |
| JOB Change 2007 (West Midlands) CIC | Administrative & support | 2017 |
| Jobhaze Ltd | Wholesale & retail | 2025 |
| Jobmate Cloud Limited | Information & communication | 2022 |
| Jobmate Group Limited | Information & communication | 2022 |
| Jobmate Holdings Limited | Financial services | 2022 |
| Jobmate Ltd | Information & communication | 2018 |
| Jobs Arena Limited | Administrative & support | 2024 |
| Jobs Group Ltd | Administrative & support | 2020 |
| Jobs NET Recruitment Consultants Limited | Administrative & support | 2024 |
| Jobsi Ltd | Professional & scientific | 2017 |
| JOBSKILLS2007 Ltd | Information & communication | 2024 |
| Jodha Jewellers Limited | Manufacturing | 2018 |
| Jodies Quality Care Ltd | Health & social care | 2022 |
| JOE and Joel Limited | Wholesale & retail | 2015 |
| JOE Sheridan Limited | Construction | 2018 |
| Joel Contracts Limited | Construction | 2016 |
| Joel's Place Ltd | Wholesale & retail | 2025 |
| Jogibal Medical Ltd | Health & social care | 2024 |
| Johal Holdco Limited | Construction | 2016 |
| Johal Residence Ltd | Real estate | 2024 |
| John Anthony Davis Limited | Extraterritorial | 2025 |
| John Ashley Exhausts Limited | Wholesale & retail | 2007 |
| John Biddle (Opticians) Limited | Wholesale & retail | 1975 |
| John Farbon UK Comp Ltd | Wholesale & retail | 2026 |
| John Grimes Fencing Limited | Manufacturing | 1990 |
| John Leason Limited | Wholesale & retail | 2003 |
| John Marston's Taverners Limited | Hospitality | 1995 |
| John Micheal Omorehiomwan Limited | Wholesale & retail | 2019 |
| John Mockler Next Level HR Consultancy Limited | Professional & scientific | 2025 |
| John Partridge & Co. Ltd | Wholesale & retail | 2012 |
| John Poole Limited | Wholesale & retail | 2014 |
| John Ryan Camera Ltd | Information & communication | 2016 |
| John Scott Works Limited | Manufacturing | 2016 |
| John Shooter Limited | Wholesale & retail | 2009 |
| John Yates & Partners LLP | | 2020 |
| Johns TM Ltd | Construction | 2024 |
| Johnson Poole & Bloomer Limited | Administrative & support | 1988 |
| Johnson Poole & Bloomer(Holdings) Limited | Professional & scientific | 2006 |
| Johnson Street Properties Ltd | Real estate | 2026 |
| Johnsons Property Management Group Ltd | Households | 2023 |
| Johnston Solar Farm Limited | Real estate | 2021 |