| JTB Holdings (Howden) Ltd | Real estate | 2025 |
| JTM Transport Services Ltd | Transport & logistics | 2025 |
| Julia Shaw Financial Adviser Limited | Financial services | 2020 |
| Junae Ltd. | Wholesale & retail | 2023 |
| Jupiter 2621 Limited | Hospitality | 2026 |
| Jupiter Cycles Ltd | Wholesale & retail | 2020 |
| Jupiter Mountain Ltd | Wholesale & retail | 2020 |
| Just Fitz Ltd | Real estate | 2019 |
| Just ICT Ltd | Information & communication | 2004 |
| Just Kebab Selby Ltd | Hospitality | 2023 |
| Just Paper Tubes Ltd | Manufacturing | 2015 |
| JW Executive Search & Consulting Ltd | Administrative & support | 2020 |
| JWW Trading Ltd | Wholesale & retail | 2023 |
| Jxwm Design Ltd | Professional & scientific | 2017 |
| K and C Love Asset Management Limited | Real estate | 2009 |
| K and C Love Limited | Professional & scientific | 2009 |
| K W Grant Ltd | Construction | 2003 |
| K&D Transportation Ltd | Transport & logistics | 2025 |
| K. S. D Transport Ltd | Transport & logistics | 2025 |
| KAG Financial Limited | Financial services | 2018 |
| Kakoon Hair & Beauty Ltd | Other services | 2024 |
| Kalar Selby Ltd | Wholesale & retail | 2025 |
| Kamil MAC Ltd | Transport & logistics | 2026 |
| Kantor Trans Limited | Transport & logistics | 2016 |
| Kaps First Impressions Limited | Other services | 2021 |
| Kastle Crushers Ltd | Construction | 2012 |
| Kate Eady Consulting Limited | Professional & scientific | 2024 |
| Katie Head Limited | Health & social care | 2023 |
| Katone Holdings Ltd | Financial services | 2022 |
| Katyu Bani Ltd | Transport & logistics | 2019 |
| KCK Pools Ltd | Construction | 2023 |
| Kclub Productions Limited | Information & communication | 2017 |
| KD Construction (Yorkshire) Ltd | Construction | 2016 |
| Keesbury Park Cawood Management Company Limited | Households | 2009 |
| Keith France Electrical Contractor Limited | Construction | 2012 |
| Keith France Holdings Ltd | Construction | 2023 |
| Keith Taylor Holdings Limited | Financial services | 2026 |
| Kendra Electrical Services Ltd | Construction | 2023 |
| Kerry'D Away Cleaning Ltd | Administrative & support | 2025 |
| Keystone Keep Ltd | Real estate | 2025 |
| Kgrit Ltd | Information & communication | 2019 |
| KHS Yorkshire Ltd | Construction | 2025 |
| Kids Corner Whitley Ltd | Health & social care | 2024 |
| Kids Korner Limited | Health & social care | 2018 |
| Kids' Corner Barlow Limited | Health & social care | 2022 |
| Kids' Corner Bridlington Limited | Health & social care | 2021 |
| Kingfield Homes Limited | Real estate | 2025 |
| Kingfisher Recruitment Solutions Limited | Professional & scientific | 2013 |
| Kiss My Glass Window Cleaning Ltd | Administrative & support | 2019 |
| KJL Performance Consulting Ltd | Professional & scientific | 2025 |
| KMM Golden Driver Ltd | Transport & logistics | 2016 |
| KMP Building Contractors Ltd | Construction | 2016 |
| Knapton Tyres Limited | Wholesale & retail | 2014 |
| Komorebi Limited | Professional & scientific | 2025 |
| Kosnik Personnel Ltd | Administrative & support | 2024 |
| KSD Cars Limited | Transport & logistics | 2025 |
| KTC Accountants Limited | Professional & scientific | 2010 |
| Kudos Leisure Ltd | Hospitality | 2017 |
| Kulpa Transport Services Ltd | Transport & logistics | 2022 |
| Kwikcab Selby Ltd | Transport & logistics | 2024 |
| L and G Film Productions Limited | Information & communication | 2019 |
| L B Hayes Limited | Agriculture & fishing | 2002 |
| L Property Ltd | Hospitality | 2023 |
| L. H. C. Cleaning Services (Yorkshire) Ltd | Administrative & support | 2016 |
| Labella Selby Limited | Hospitality | 2024 |
| Lady L Developments Limited | Construction | 2021 |
| Lakeland Leather Limited | Wholesale & retail | 2007 |
| Lakes Capital Limited | Professional & scientific | 2021 |
| Lakeside Property Management Limited | Real estate | 2004 |
| Lakeview Financial Services Ltd | Financial services | 2019 |
| Lambert Consulting Limited | Construction | 2015 |
| Lambert-Dowell Ltd | Professional & scientific | 2009 |
| Lampetia Ltd | Construction | 2010 |
| Lanni Building Contractors Ltd | Construction | 2024 |
| Lavender Croft (Bubwith) Management Company Limited | Households | 2020 |
| Lavender Tech Limited | Arts & recreation | 2017 |
| Law Electrical (Selby) Ltd | Construction | 2009 |
| Lawai Spice Selby Ltd | Hospitality | 2024 |
| LAWN3 North Yorks Limited | Administrative & support | 2023 |
| LB SW Ltd | Health & social care | 2018 |
| LBN Property Ltd | Real estate | 2025 |
| LCI Controls Ltd | Construction | 2009 |
| LCS Agriculture Limited | Agriculture & fishing | 2003 |
| LCS Crane Hire Limited | Transport & logistics | 2003 |
| Leadby Consulting Limited | Information & communication | 2013 |
| Leaktech (Northern) Limited | Professional & scientific | 2020 |
| Ledbrook & Hardwick Employment Law and HR Services Limited | Professional & scientific | 2014 |
| Ledmar Logistics Ltd | Transport & logistics | 2021 |
| Leeds Roller Derby Limited | Arts & recreation | 2010 |
| Legacy Skills Group Limited | Administrative & support | 2020 |
| Lemrich Limited | Hospitality | 2024 |
| Leng Ltd | Manufacturing | 2023 |
| Leonidas Enterprises Ltd | Financial services | 2021 |
| Lesters Farm Machinery Limited | Wholesale & retail | 1999 |
| Lesters Investments Ltd | Financial services | 2012 |
| Letscohost Limited | Real estate | 2025 |
| Level 7 Logistics Limited | Professional & scientific | 2008 |
| Lewis Beaton Creative Ltd | Professional & scientific | 2018 |
| LHE Electrical Ltd | Construction | 2023 |
| Lindley Crane and Plant Hire Limited | Administrative & support | 2006 |