| Jane Hernon Interior Architecture and Design Limited | Professional & scientific | 2019 |
| Jane Tindall Limited | Professional & scientific | 2013 |
| Janus Interiors Bingley Ltd | Wholesale & retail | 2015 |
| Janusian HR Limited | Administrative & support | 2016 |
| Java JOE Coffee House Limited | Hospitality | 2015 |
| JAY Consultancy Limited | Professional & scientific | 2012 |
| JB Creative Copy Ltd | Professional & scientific | 2023 |
| JBP Property Ltd | Real estate | 2024 |
| JC Wrangers Limited | Professional & scientific | 2016 |
| JCT Legal Services Limited | Professional & scientific | 2013 |
| JDC Consult Ltd | Information & communication | 2025 |
| JDH Property Investments Limited | Real estate | 2021 |
| JDP Finance Limited | Financial services | 2020 |
| JDR Consulting Services Ltd | Professional & scientific | 2023 |
| Jeff Barlow Consultancy Limited | Health & social care | 2020 |
| Jempire Property Limited | Real estate | 2025 |
| Jenni Smith Limited | Information & communication | 2016 |
| Jerry Gross Limited | Professional & scientific | 2008 |
| JH Vapes & Beverages Limited | Wholesale & retail | 2022 |
| JHA Retail Limited | Wholesale & retail | 2026 |
| JHT Consultants Limited | Professional & scientific | 2024 |
| Jigsaw Writing Solutions Limited | Professional & scientific | 2006 |
| Jimmy Anson Specialist Services Ltd | Professional & scientific | 2021 |
| Jivanji Holdings Ltd | Real estate | 2013 |
| JKL Property Investment Company Limited | Administrative & support | 2004 |
| JKN Oiltools Limited | Professional & scientific | 2013 |
| JLM M&E Ltd | Construction | 2018 |
| JM Developments (Ilkley) Ltd | Construction | 2017 |
| JM Pathways Ltd | Professional & scientific | 2025 |
| JMB Medical Imaging & Intervention Limited | Health & social care | 2019 |
| JMG Capital (Yorkshire) Limited | Real estate | 2021 |
| Jmkb Limited | Professional & scientific | 2026 |
| JMS London Limited | Information & communication | 2007 |
| John & PS Property Ltd | Real estate | 2024 |
| John Caddick Electrical Contractor Ltd | Construction | 2020 |
| John Coldwell Limited | Administrative & support | 2019 |
| John Henry Plumbing Limited | Construction | 2016 |
| Joint Working Associates Ltd | Professional & scientific | 2018 |
| Jonathan Brooks Booksales Limited | Wholesale & retail | 2006 |
| Jones Lettings Ltd | Real estate | 2015 |
| Jortrip Limited | Real estate | 2016 |
| JP & LE Rentals Ltd | Real estate | 2021 |
| JP Racing Club Limited | Arts & recreation | 2020 |
| Jpsp Limited | Administrative & support | 2001 |
| JRH Investments Ltd | Real estate | 2021 |
| JSM Holdings (Menston) Ltd | Real estate | 2022 |
| JSM Law Ltd | Administrative & support | 2024 |
| JSM Wilkinson Limited | Hospitality | 2017 |
| Jszn Design Limited | Professional & scientific | 2013 |
| JTM Local Stores Ltd | Wholesale & retail | 2019 |
| Junipert Ltd | Real estate | 2021 |
| Just Because Properties Limited | Real estate | 2025 |
| Just for YOU Care (Ilkley & Surrounding Area) Limited | Other services | 2011 |
| Just Swimming Caps Limited | Wholesale & retail | 2021 |
| JVV Operations Limited | Real estate | 2025 |
| JW Joinery & Design Ltd | Construction | 2025 |
| Jwsl Investments Limited | Real estate | 2024 |
| K Clarke Design Ltd | Professional & scientific | 2021 |
| K Houchen Building Contractors Ltd | Construction | 2018 |
| K Parmar Ltd | Wholesale & retail | 2011 |
| K Property Group Ltd | Real estate | 2020 |
| K4 Transport Limited | Transport & logistics | 2012 |
| KAH Smart Family Group Ltd | Financial services | 2022 |
| Kaizen Heart Ltd | Professional & scientific | 2025 |
| Kashmiri Aroma (Bradford) LLP | | 2018 |
| Kasma Ltd | Professional & scientific | 2017 |
| Katie Brindle Limited | Professional & scientific | 2018 |
| KAY & Co Insurance Brokers Ltd | Administrative & support | 2016 |
| KB 49 Holdings Ltd | Real estate | 2018 |
| Kearns and Partners Limited Liability Partnership | | 2009 |
| Kearns Properties Limited | Construction | 2003 |
| Keighley Contract Services Ltd | Administrative & support | 2020 |
| Keighley Properties Limited | Construction | 2014 |
| Kelp and KIN Limited | Arts & recreation | 2017 |
| Kenneth Medical Limited | Health & social care | 2019 |
| Kenton Ensink Training Ltd | Education | 2024 |
| Kernahan Building Contractors Limited | Construction | 2009 |
| Kevin John Pyatt Limited | Hospitality | 2024 |
| Key to Achieving Therapy Services Ltd | Health & social care | 2016 |
| Keystone Financial Management Limited | Financial services | 2017 |
| Keystone Financial Planning Limited | Financial services | 2025 |
| Keystone Site Cleaning Ltd | Administrative & support | 2026 |
| KGW Surveyors Limited | Professional & scientific | 2012 |
| Kilroy Property Ltd | Real estate | 2025 |
| Kind Hands Caring Services Limited | Health & social care | 2006 |
| Kind Kiwi Holdings UK Limited | Real estate | 2023 |
| Kinship Wines Ltd | Wholesale & retail | 2026 |
| Kirbyville Limited | Households | 1983 |
| Kissing Gate Photography Ltd | Extraterritorial | 2015 |
| Kivan Nova Investments Ltd | Real estate | 2025 |
| Kiwi Limited | Construction | 2009 |
| Klasse Corporation Ltd | Construction | 2016 |
| Knoll Textiles Holdings Limited | Financial services | 2025 |
| Knoll Yarns Limited | Wholesale & retail | 1978 |
| Komu Drones Ltd | Construction | 2025 |
| Kopal Impex Ltd. | Wholesale & retail | 2015 |
| Krypton Kitchens and Bedrooms Limited | Manufacturing | 2011 |
| Kumo Shima Ltd | Real estate | 2023 |
| Kurt Handyman Services Ltd | Construction | 2020 |
| L T Cleaning Services Limited | Administrative & support | 2003 |