| JBD Europe Limited | Professional & scientific | 2012 |
| JBD Properties (Yorkshire) Ltd | Real estate | 2023 |
| JBH GAS and Plumbing Limited | Construction | 2026 |
| JC Python Analytics Ltd | Professional & scientific | 2023 |
| JCB MED Healthcare Limited | Professional & scientific | 2023 |
| JD Jetwashing Limited | Administrative & support | 2025 |
| JD Martial Arts Limited | Wholesale & retail | 2023 |
| Jd's Eco Friendly Waste Services Ltd | Water & waste | 2025 |
| Jeffery Consultants Limited | Construction | 2023 |
| Jeiz Ltd | Hospitality | 2015 |
| Jelish Limited | Real estate | 2020 |
| Jellicoe Installation Limited | Construction | 2025 |
| Jenson Homes Ltd | Real estate | 2025 |
| Jensten Insurance Brokers (Yorkshire & Humberside) Ltd | Financial services | 1941 |
| JEP Pubs Limited | Hospitality | 2025 |
| Jeremy's Cafe Bar Limited | Hospitality | 2025 |
| JF IT Services Ltd | Information & communication | 2018 |
| JFW Services (West Yorkshire) Ltd | Other services | 2025 |
| Jialen Sing Ltd | Wholesale & retail | 2026 |
| Jiffy Trucks Holdings Limited | Professional & scientific | 2008 |
| Jiffy Trucks Limited | Manufacturing | 1974 |
| JJ Technical Ltd | Construction | 2025 |
| Jj&Co Ltd | Administrative & support | 2025 |
| Jjeb Developments Limited | Real estate | 2002 |
| Jkendell Ltd | Other services | 2022 |
| JKJ 67 Properties Ltd | Households | 2024 |
| JKR Medicals Ltd | Health & social care | 2019 |
| JLB Fabric Ltd | Wholesale & retail | 2020 |
| JLV Properties Ltd | Real estate | 2026 |
| JMS Construction and Maintenance Limited | Construction | 2021 |
| JNR Cooling Ltd | Construction | 2024 |
| John Kearns Butchers Ltd | Wholesale & retail | 2013 |
| Johnsons Signs & Engravers Limited | Manufacturing | 2005 |
| Joint Activities and Motor Education Service (James) | Wholesale & retail | 1996 |
| Jolly Bean Roastery Ltd | Manufacturing | 2024 |
| Jolly Brenny Ltd | Professional & scientific | 2020 |
| JON Rushton Film Publicity and Consultancy Limited | Professional & scientific | 2016 |
| Jonathan Baxter Limited | Education | 2026 |
| Jonathan Kerr Dormant Limited | Professional & scientific | 1994 |
| Jorvik Business Consultancy Limited | Administrative & support | 2019 |
| Joshua Hart Photo Limited | Professional & scientific | 2025 |
| JP GAS Services Ltd | Construction | 2010 |
| JPW Tech Ltd | Information & communication | 2024 |
| JRJ Technology Limited | Information & communication | 2018 |
| JRW & Co Windows and Doors Limited | Construction | 2025 |
| JS Healthcare Services Limited | Health & social care | 2015 |
| JS Risk & Controls Limited | Professional & scientific | 2013 |
| Jtma Investment Limited | Financial services | 2021 |
| Jubilee Garage Shipley Limited | Wholesale & retail | 2022 |
| Jugnu Film Productions Limited | Information & communication | 2008 |
| Jukes Joinery & Building Services Limited | Construction | 2018 |
| Julie Whiting Consultancy Ltd | Hospitality | 2023 |
| Jump JET Ltd | Wholesale & retail | 2014 |
| Junaid Khan Trading Ltd | Health & social care | 2025 |
| Jupiter Consultants Ltd | Professional & scientific | 2019 |
| Just Desserts Yorkshire Limited | Manufacturing | 2012 |
| Just OK Services Limited | Administrative & support | 2015 |
| Just Stock Trading Limited | Wholesale & retail | 2024 |
| JVC Building & Construction Limited | Construction | 2026 |
| JW Translation Ltd | Professional & scientific | 2022 |
| K and M Property Services (Yorkshire) Limited | Construction | 2014 |
| K Deen Ltd | Real estate | 2025 |
| K-Tec Electrical Limited | Wholesale & retail | 2009 |
| K.D. World Limited | Other services | 2013 |
| K.G.T. Advanced Hair, Beauty and Skin Specialists Limited | Other services | 2012 |
| K.M. Davies Furnishings Limited | Wholesale & retail | 1991 |
| K7 Logistics Ltd | Transport & logistics | 2021 |
| K9 Grass Ltd | Manufacturing | 2025 |
| K9 Turf Europe Ltd | Manufacturing | 2019 |
| K9 Turf Limited | Manufacturing | 2022 |
| K9 Turf Yorkshire Ltd | Administrative & support | 2021 |
| Kamec UK Ltd | Professional & scientific | 2020 |
| Karen Eckstein Ltd | Public administration | 2020 |
| Karma Fashion Limited | Wholesale & retail | 2026 |
| Kashmiri Aroma (Baildon) LLP | | 2023 |
| Katie Gardens Limited | Financial services | 2022 |
| Katy LE Ltd | Other services | 2025 |
| Kauser Developments Ltd | Health & social care | 2024 |
| KAY DEE Engineering (Plastics) Limited | Manufacturing | 1979 |
| KAY JAY Management Ltd | Professional & scientific | 2025 |
| Kaylan Offshore Limited | Manufacturing | 2013 |
| KCB Enterprise Ltd | Wholesale & retail | 2012 |
| KCB Ventures Limited | Real estate | 2020 |
| Kdep Holdings Limited | Financial services | 2013 |
| KEB Productions Ltd | Professional & scientific | 2022 |
| KEB Property Ltd | Real estate | 2023 |
| Keen EYE Copywriting Ltd | Professional & scientific | 2022 |
| KEG MAN Limited | Wholesale & retail | 2020 |
| Keighley Engraving Ltd | Manufacturing | 2021 |
| Kendene Limited | Real estate | 2002 |
| Kenworth Properties Limited | Real estate | 2025 |
| Kerrzinga Ltd | Information & communication | 2014 |
| Keswick Roofing and Maintenance Limited | Construction | 2021 |
| Keszen Rouge Ltd | Other services | 2016 |
| Key Care Limited | Financial services | 1977 |
| Key in Properties Limited | Real estate | 2017 |
| Key Verse Automotive Ltd | Construction | 2026 |
| KFM Quality Ltd | Construction | 2014 |
| Khruawantanee Ltd | Hospitality | 2025 |
| Kickstart Swimming Academy Ltd | Education | 2022 |