| KK Housing Ltd | Real estate | 2020 |
| KL Marketing Ltd | Wholesale & retail | 2025 |
| KL Optics Ltd | Wholesale & retail | 2026 |
| KLN Law Ltd | Professional & scientific | 2025 |
| KLS (Manchester) Ltd | Professional & scientific | 2024 |
| KLW Developments Limited | Real estate | 2021 |
| KLW Family Office Limited | Extraterritorial | 2024 |
| KM Business Services Limited | Administrative & support | 2025 |
| KM Construction NW Ltd | Construction | 2023 |
| KM Electrical Limited | Construction | 2017 |
| KM Properties and Lettings Ltd | Real estate | 2025 |
| Kmctattoo Limited | Other services | 2025 |
| KMM Brickwork Ltd | Construction | 2025 |
| KMM Developments Ltd | Professional & scientific | 2015 |
| KMM Homes Ltd | Administrative & support | 2017 |
| KMM Properties (NW) Limited | Real estate | 2018 |
| KMR Takeaway Ltd | Hospitality | 2018 |
| Knott Hill Farm Livery Stables Limited | Administrative & support | 2010 |
| KNS Groundwork Ltd | Construction | 2024 |
| Konrad Transport Limited | Transport & logistics | 2017 |
| Kore by Kiera DEE Ltd | Health & social care | 2024 |
| Kowall Services Limited | Professional & scientific | 2026 |
| KP Property Incorporation Ltd | Real estate | 2025 |
| KPI Accountants Ltd | Professional & scientific | 2016 |
| KR Apparels Ltd | Manufacturing | 2015 |
| Krakow Food Ltd | Wholesale & retail | 2024 |
| Krushnam Ltd | Wholesale & retail | 2026 |
| Krypton Enterprise Ltd | Wholesale & retail | 2022 |
| KS Professional Roofing Services Ltd | Construction | 2023 |
| Kt's Food and Booze Limited | Wholesale & retail | 2026 |
| Kufta Transporter Ltd | Wholesale & retail | 2025 |
| Kulosa Events Ltd | Arts & recreation | 2025 |
| KW Management Ltd | Professional & scientific | 2026 |
| Kwanjai Thai Spa Ltd | Other services | 2022 |
| L a Signs Ltd | Professional & scientific | 2010 |
| L Fernley Ltd | Financial services | 2021 |
| L J Mccance Ltd | Extraterritorial | 2017 |
| L K Manning Ltd | Administrative & support | 2026 |
| L Pattison Group Ltd | Professional & scientific | 2024 |
| L Rhodes & SON Ltd | Transport & logistics | 2015 |
| L&M Life Ltd | Wholesale & retail | 2024 |
| L&P Accountancy Services Limited | Professional & scientific | 2019 |
| L. I. Property Investments Limited | Real estate | 2020 |
| L.E.S.S. UK Limited | Health & social care | 1990 |
| L2F Direct Limited | Wholesale & retail | 2023 |
| Laburnum Ltd | Wholesale & retail | 2026 |
| LAD Property Services Limited | Construction | 2008 |
| Ladbroke MOT Services Limited | Wholesale & retail | 2011 |
| Lahore Services Group Limited | Administrative & support | 2019 |
| Lambardar Trading Ltd | Wholesale & retail | 2022 |
| Lancashire PAK Properties Ltd | Real estate | 2020 |
| Landandform Ltd | Professional & scientific | 2024 |
| Lang Financial Holding Ltd | Financial services | 2023 |
| Laser Labb & Co Ltd | Other services | 2025 |
| Laser Pro Limited | Other services | 2019 |
| Lashes by Kirsty Limited | Other services | 2025 |
| Last Kingdom Limited | Construction | 2020 |
| Lauda Cartoons Studio Ltd | Information & communication | 2024 |
| Lauren Edwards Limited | Hospitality | 2018 |
| Laurentiu Sorin Limited | Transport & logistics | 2012 |
| LB Telecom & Data Limited | Information & communication | 2013 |
| LB Telecommunications Ltd | Information & communication | 2020 |
| LBG875 Limited | Education | 2021 |
| LCC NW Ltd | Energy | 2021 |
| LCM Farriery Services Limited | Professional & scientific | 2024 |
| LCS Eco Build Ltd | Construction | 2020 |
| LEA Mount Management Limited | Households | 1992 |
| LED OUT of the Box Ltd | Manufacturing | 2017 |
| Ledger Financial Ltd | Professional & scientific | 2020 |
| LEE & Co (UK) Ltd | Hospitality | 2011 |
| LEE Burnham Holdings Ltd | Financial services | 2025 |
| Leejo Ltd | Wholesale & retail | 2016 |
| Leepres Care Limited | Health & social care | 2015 |
| Leffis Organic Limited | Wholesale & retail | 2025 |
| Leisure Grass UK Ltd | Administrative & support | 2012 |
| Leitrim Civils Ltd | Construction | 2020 |
| LEJ Northern Ltd | Real estate | 2021 |
| Lemrend Rendering Services Ltd | Construction | 2022 |
| Lemunn Ltd | Manufacturing | 2026 |
| LEO15 Limited | Wholesale & retail | 2017 |
| Leondevelopers Limited | Wholesale & retail | 2024 |
| Level - TEC Limited | Professional & scientific | 2007 |
| Lexor Ledgers Ltd | Professional & scientific | 2025 |
| LG Associates Limited | Professional & scientific | 2024 |
| LGM Auto's Spares Limited | Wholesale & retail | 2015 |
| Liberton Investigations Ltd | Administrative & support | 2012 |
| Licka-Lota-Deals Ltd | Wholesale & retail | 2026 |
| Lighthouse Collaborative Care Limited | Health & social care | 2023 |
| Lighthouse Digital Studio Ltd | Professional & scientific | 2007 |
| LIL Lisa Ltd | Hospitality | 2025 |
| Lily's Indian Vegetarian Cuisine Limited | Hospitality | 2004 |
| Limb Limited | Wholesale & retail | 2014 |
| Limehurst Farm Livery Ltd | Administrative & support | 2024 |
| Lina Grace Ltd | Wholesale & retail | 2025 |
| Linco Property Ltd | Real estate | 2025 |
| Linda's Secret Ltd | Wholesale & retail | 2024 |
| Linen Concepts Ltd | Administrative & support | 2024 |
| Linenhub Limited | Wholesale & retail | 2025 |
| Linh Associates Ltd | Health & social care | 2015 |
| Link Care Homes Limited | Health & social care | 2025 |