| Jj's Gift Ideas Ltd | Wholesale & retail | 2026 |
| JK Carr Ltd | Health & social care | 2011 |
| JK Cars Ltd | Wholesale & retail | 2025 |
| JK Express Services Ltd | Transport & logistics | 2018 |
| JK Telecomms Ltd | Construction | 2023 |
| JKC Consulting Ltd | Professional & scientific | 2024 |
| JLC Telecommunications Ltd | Information & communication | 2004 |
| JLD Property Solutions Limited | Real estate | 2023 |
| JLM Commercial Property Ltd | Real estate | 2023 |
| JLM Pro Ltd | Wholesale & retail | 2015 |
| JLM Property Lettings Ltd | Real estate | 2018 |
| JM Bateman Limited | Construction | 2006 |
| JMG Couriers Ltd | Transport & logistics | 2026 |
| JMG Engineering Solutions Limited | Professional & scientific | 2022 |
| JMJ Mortgages Limited | Financial services | 2023 |
| Jmrob Ltd | Other services | 2022 |
| JO Breeze Aesthetics Beauty Training Ltd | Education | 2020 |
| Joal Joinery Limited | Construction | 2005 |
| Jodie Pepper Virtual Assistant Limited | Administrative & support | 2024 |
| JOE Hawden Financial Planning Ltd | Professional & scientific | 2018 |
| John Brook Events Ltd | Administrative & support | 2016 |
| John Massarella Limited | Real estate | 1969 |
| John Swaby Logistics Limited | Transport & logistics | 2019 |
| Johnstons Property Ltd | Real estate | 2021 |
| Jonathan Hampton Ltd | Professional & scientific | 2021 |
| Jonathan Hull & SON Ltd | Wholesale & retail | 2022 |
| Jordan Developments Ltd | Construction | 1999 |
| Jordan Properties Yorkshire Ltd | Real estate | 2025 |
| Joshsam Limited | Health & social care | 2018 |
| Jotpa IT Consultancy Limited | Information & communication | 2025 |
| Joule Engineering Services Limited | Construction | 1999 |
| Joule Hot Water Systems UK Ltd | Manufacturing | 2011 |
| Joys House Ltd | Real estate | 2021 |
| JP Advisory Ltd | Professional & scientific | 2025 |
| JP Builders Merchant Ltd | Wholesale & retail | 2012 |
| JP GAS Installations Limited | Construction | 2017 |
| JP Homes (Yorkshire) Limited | Construction | 2025 |
| JPT Plumbing & Heating Services Ltd | Construction | 2020 |
| Jpwalker Property Ltd | Households | 2026 |
| JR Brand Marketing Ltd | Professional & scientific | 2024 |
| JR Hardwick Ltd | Information & communication | 2022 |
| JRC Automotive Ltd | Wholesale & retail | 2020 |
| JRC Properties Ltd | Construction | 2024 |
| JRS Estates Ltd | Real estate | 2022 |
| JS Electrical Controls / Installations Ltd | Construction | 2007 |
| JSD Driveways Ltd | Construction | 2025 |
| JSD Education Support Ltd | Education | 2016 |
| JT Home Improvements Limited | Construction | 2026 |
| JT Precision Engineering Ltd | Construction | 2026 |
| JTA Transport Limited | Transport & logistics | 2019 |
| Junior Kitchen North Community Interest Company | Hospitality | 2018 |
| Just Football Foundation CIC | Arts & recreation | 2021 |
| Justin Scott Chiropractic Ltd | Health & social care | 2022 |
| Justtradingminis Ltd | Wholesale & retail | 2026 |
| JW Dale Coffee Ltd | Hospitality | 2025 |
| JW Precision Wood Panels Limited | Construction | 2015 |
| JWB Housing Ltd | Real estate | 2024 |
| JWF Shaw (Electrical Installations) Limited | Construction | 2015 |
| JXL Performance Ltd | Wholesale & retail | 2023 |
| K & T Oral Health Care Ltd | Health & social care | 2009 |
| K Gate Shop Ltd | Wholesale & retail | 2018 |
| K J and Son's Ltd | Construction | 2008 |
| K J Carr Limited | Professional & scientific | 2012 |
| K L King Accountants Limited | Professional & scientific | 2017 |
| K Mofrad Properties Limited | Real estate | 2025 |
| K Nails 99 Ltd | Other services | 2026 |
| K&K Direct Limited | Transport & logistics | 2024 |
| K&K Fancy Bubbles Ltd | Arts & recreation | 2026 |
| K. Glazing Limited | Manufacturing | 2003 |
| K.L.M. Building Contractors Co. Limited | Construction | 1973 |
| K.M. Refurbishments Ltd | Construction | 2024 |
| Kairos Personnel Ltd | Administrative & support | 2022 |
| Kairos Social Care Ltd | Health & social care | 2021 |
| Kaka Hemsworth Ltd | Other services | 2021 |
| Kanart Ltd | Transport & logistics | 2012 |
| Kanart Properties Ltd | Real estate | 2019 |
| Karahan Delivery & Transport Ltd | Transport & logistics | 2019 |
| Karen Betts & Co Holdings Limited | Financial services | 2025 |
| Karen Betts Beauty Limited | Wholesale & retail | 2025 |
| Karen Betts Clinic's Limited | Other services | 2006 |
| Karen Betts Holdings Limited | Real estate | 2019 |
| Kasikai Ltd | Health & social care | 2019 |
| Katrhea Limited | Real estate | 2025 |
| KAY4 Group Ltd | Health & social care | 2020 |
| Kayasan Yorkshire Limited | Hospitality | 2017 |
| Kazarius Limited | Arts & recreation | 2026 |
| KCH Change Management Limited | Administrative & support | 2024 |
| KCK Housing Ltd | Construction | 2025 |
| KCK Property Ltd | Real estate | 2026 |
| Kcoe Limited | Information & communication | 2024 |
| Kellycraft Ltd | Wholesale & retail | 2015 |
| Kelwood Machinery Limited | Professional & scientific | 2009 |
| Kendall Medical Services Ltd | Health & social care | 2018 |
| Kenilla Ltd | Health & social care | 2019 |
| Kerb Protect Ltd | Wholesale & retail | 2019 |
| Kestrel Real Estate Ltd | Real estate | 2025 |
| Key Installations U.K Ltd | Construction | 2018 |
| Keys Holdings Limited | Agriculture & fishing | 2015 |
| Keystream Limited | Manufacturing | 2007 |
| Khawars Ranch (Pontefract) Ltd | Hospitality | 2016 |