| Killshot Pest Control Ltd | Administrative & support | 2025 |
| KIM Henry Limited | Other services | 2022 |
| KIN6MARK Ltd | Manufacturing | 2018 |
| King Street Garage Ltd | Wholesale & retail | 2009 |
| Kingdom House Developments Ltd | Real estate | 2019 |
| Kingsway Draughting Services Limited | Professional & scientific | 2015 |
| Kinsley Boys Football Club CIC | Arts & recreation | 2019 |
| Kinsley Greyhound Stadium Limited | Arts & recreation | 2009 |
| Kinsley MOT Centre Ltd | Professional & scientific | 2018 |
| Kinsley Timber Supplies Limited | Manufacturing | 2002 |
| Kinsley Tyres Limited | Wholesale & retail | 2011 |
| Kinwood Group Limited | Financial services | 2025 |
| Kirkby 2017 Limited | Financial services | 2017 |
| Kirkby's Fast Food Ltd | Hospitality | 2024 |
| Kirkbygate Auto Centre Ltd | Wholesale & retail | 2021 |
| Kirkbygate Tyres & Garage Ltd | Manufacturing | 2015 |
| Kizmoon Ltd | Wholesale & retail | 2022 |
| KJ Salesprofessional Ltd | Wholesale & retail | 2023 |
| Kj&Co Ltd | Wholesale & retail | 2022 |
| Kleman Sushi Co Ltd | Wholesale & retail | 2024 |
| Kloay's Care Ltd | Health & social care | 2017 |
| KMS S&A Ltd | Transport & logistics | 2016 |
| Knight-Reevell Limited | Real estate | 2023 |
| Knights Fish & Chips Ltd | Hospitality | 2017 |
| Knottingley Motor Wreckers Limited | Wholesale & retail | 2013 |
| Koby Studio Limited | Administrative & support | 2017 |
| Kokofoodies Ltd | Hospitality | 2025 |
| Kondo Yamada Systems and Services Limited | Information & communication | 2019 |
| Kreations by KAZ Limited | Wholesale & retail | 2017 |
| Kris Freight Limited | Administrative & support | 2017 |
| Krystal Hope Ltd | Health & social care | 2022 |
| Ktcladding Ltd | Wholesale & retail | 2022 |
| KTK Ventures Limited | Real estate | 2024 |
| Kuba Trans Ltd | Transport & logistics | 2018 |
| Kucharczyk Ltd | Transport & logistics | 2019 |
| Kurly Planet Ltd | Wholesale & retail | 2018 |
| Kwimbo C.I.C. | Administrative & support | 2022 |
| Kyte Limited | Hospitality | 2008 |
| L & J Contract Flooring Limited | Extraterritorial | 2014 |
| L B Electrical Limited | Construction | 2015 |
| L Baker Enterprises Ltd | Transport & logistics | 2024 |
| L R News Ltd | Wholesale & retail | 2012 |
| L&G Roofing Services Limited | Construction | 2026 |
| LA 2012 Limited | Manufacturing | 2004 |
| LA Pizzeria Ltd | Hospitality | 2024 |
| Ladybalk Ltd | Hospitality | 2012 |
| Ladywell Ventures Limited | Construction | 2025 |
| Lala Barbers 17 Ltd | Other services | 2024 |
| Lalo Mini Market 16 Ltd | Wholesale & retail | 2025 |
| Lamontgarner Limited | Real estate | 2017 |
| Lancaster Memorials Limited | Wholesale & retail | 2003 |
| Langthwaite Business Association Ltd | Other services | 2005 |
| Langthwaite Storage & Distribution Limited | Transport & logistics | 2008 |
| Lansdell Renewable Services Yorkshire Ltd | Construction | 2025 |
| Larch Gate Implants Ltd | Health & social care | 2024 |
| Lass Services Ltd | Transport & logistics | 2023 |
| Lasting Touch Limited | Manufacturing | 2023 |
| Latch Technologies Limited | Wholesale & retail | 2020 |
| Lauren Spanton Ltd | Transport & logistics | 2026 |
| Lavie Nails & Beauty Ltd | Other services | 2026 |
| Lawson Solutions Limited | Professional & scientific | 2022 |
| LBC Cladding Ltd | Construction | 2017 |
| LBS Electrical Ltd | Construction | 2025 |
| LCA Lettings Limited | Real estate | 2025 |
| LDC Driving Schools Limited | Education | 1991 |
| LDG Engineering Ltd | Professional & scientific | 2024 |
| LE Cars Ltd | Wholesale & retail | 2026 |
| Lead Technical Services Ltd | Professional & scientific | 1999 |
| Leap Accountancy Limited | Professional & scientific | 2014 |
| Learner Driving Centres Limited | Professional & scientific | 2002 |
| LED Associates Ltd | Professional & scientific | 2023 |
| Leda Online Ltd | Professional & scientific | 2025 |
| Ledger Logistics Limited | Transport & logistics | 2013 |
| Leeds Ductwork Services Limited | Manufacturing | 2012 |
| Leeds GAS Ltd | Construction | 2023 |
| Leewires Limited | Construction | 2017 |
| Legn Contracting Services Limited | Construction | 2022 |
| Lenticular Aviation Ltd | Manufacturing | 2020 |
| Lenticular Services Ltd | Professional & scientific | 2021 |
| Leonvexa Ltd | Information & communication | 2025 |
| LET North Property Group Ltd | Real estate | 2019 |
| Lethaus LLP | | 2026 |
| LG Hemsworth Limited | Hospitality | 2022 |
| LH Psychology Ltd | Education | 2021 |
| LHC Plastering & Rendering Ltd | Construction | 2023 |
| Libbi Interiors Limited | Other services | 2016 |
| Libbi Properties Ltd | Real estate | 2022 |
| Liberty Legal & Financial Services Limited | Professional & scientific | 2007 |
| Liberty Legal Services Limited | Professional & scientific | 2010 |
| Liberty Probate Services Limited | Professional & scientific | 2009 |
| Liberty TRS Limited | Other services | 2018 |
| Liberty Wills Limited | Professional & scientific | 2013 |
| Lightclife Property Investment Ltd | Real estate | 2012 |
| Lighting Jacks Ltd | Construction | 2011 |
| Lila Project CIC | Health & social care | 2026 |
| Limbert Brothers Limited | Construction | 2003 |
| Limbert Pipelines Limited | Manufacturing | 2012 |
| Limelight Estates Ltd | Real estate | 2023 |
| Linea Rossa Autorefinishing Ltd | Wholesale & retail | 2011 |
| Linpac Environmental Limited | Manufacturing | 2005 |