| Kcmw Enterprises Ltd | Wholesale & retail | 2025 |
| Keble Court (Stamford) Limited | Households | 1976 |
| Keeprising Limited | Real estate | 1984 |
| KEL Property Ltd | Real estate | 2021 |
| Kelsa Limited | Hospitality | 2025 |
| Kendik Ltd | Real estate | 2020 |
| Kennington Commercials Limited | Wholesale & retail | 2012 |
| Kensington Homes Capital Ventures Ltd | Real estate | 2023 |
| Kent Construction Business Ltd | Construction | 2023 |
| Kent Construction Stamford Ltd | Construction | 2026 |
| Key Publishing Limited | Information & communication | 1992 |
| Keystone Collective Ltd | Construction | 2016 |
| Keystone Paraplanning Ltd | Administrative & support | 2021 |
| Kezan Limited | Hospitality | 2024 |
| KG Retreats Ltd | Hospitality | 2023 |
| KGB Infrastructure Services Limited | Professional & scientific | 2019 |
| Kick Consultancy Ltd | Professional & scientific | 2023 |
| KIM J Creative Limited | Arts & recreation | 2025 |
| Kimble Property Limited | Real estate | 2017 |
| Kindred House Advisory Ltd | Professional & scientific | 2025 |
| Kings Accounting Services Ltd | Professional & scientific | 2018 |
| Kirby Electrical Contracts Limited | Manufacturing | 2013 |
| Kirk Marketing and Media Ltd | Professional & scientific | 2013 |
| Kitesr Ltd | Wholesale & retail | 2023 |
| Kittisaks Muay Thai Ltd | Arts & recreation | 2019 |
| Kiwitech UK Limited | Extraterritorial | 2016 |
| KJA Developments Ltd | Construction | 2025 |
| KJE Services Limited | Professional & scientific | 2023 |
| KJW Automotive Limited | Manufacturing | 2013 |
| KLA Skin Limited | Wholesale & retail | 2025 |
| Klavis Holdings Limited | Professional & scientific | 1978 |
| Klimes & Co Ltd | Real estate | 2005 |
| Kmck Ltd | Transport & logistics | 2018 |
| Kopriva Ltd | Professional & scientific | 2013 |
| Kozi Course Limited | Education | 2021 |
| KPB Property Enterprises Ltd | Real estate | 2024 |
| Krushr Limited | Manufacturing | 2006 |
| KSA Commercial Ltd. | Real estate | 2012 |
| Ktlifestyle Ltd | Wholesale & retail | 2025 |
| Ktvision Limited | Information & communication | 2021 |
| Kumusha Limited | Real estate | 2019 |
| Kwik Surfacing Limited | Construction | 2007 |
| L.P Tyres Ltd | Wholesale & retail | 2012 |
| L52 Limited | Construction | 2022 |
| LAB Films Global Ltd | Information & communication | 2026 |
| LAB Property Holdings Ltd | Real estate | 2024 |
| LAC Civils Limited | Construction | 2017 |
| Lackenby Energy Limited | Energy | 2022 |
| Laidler Homecare Services Ltd | Health & social care | 2024 |
| Laird Norfolk Homes Ltd | Hospitality | 2018 |
| Lakeside Clubhouse Limited | Hospitality | 2020 |
| Land Girls Ltd | Wholesale & retail | 2022 |
| Landmark Financial Group Limited | Financial services | 2017 |
| Landmark Group EOT Limited | Financial services | 2022 |
| Landmark IFA Limited | Financial services | 2003 |
| Landmark Media International Limited | Administrative & support | 2006 |
| Landmark Sports Marketing Ltd | Professional & scientific | 2015 |
| Lanehouse Investments Ltd | Real estate | 2023 |
| Laneshift Ltd | Information & communication | 2026 |
| Lang Learning Systems Ltd | Education | 2025 |
| Langheath Limited | | 1987 |
| Lanzarote Estates and Leisure Limited | Real estate | 1981 |
| Lartec Power Ltd | Wholesale & retail | 2014 |
| Lauda Technology Limited | Wholesale & retail | 2012 |
| Lauren Crowe Ltd | Professional & scientific | 2024 |
| Lawton Consulting Services Ltd | Professional & scientific | 2017 |
| LB Homes Limited | Construction | 2007 |
| LBD Danielle Ltd | Other services | 2025 |
| Lbear Ltd | Information & communication | 2014 |
| LCP Chelsea Limited | Extraterritorial | 2006 |
| LCP Depots Limited | Real estate | 2025 |
| LCP Fleetfoot Limited | Real estate | 2025 |
| LCP Harlesden Limited | Transport & logistics | 1996 |
| LCP Lock-Up Garages Limited | Real estate | 2016 |
| LCP Parking Services Limited | Transport & logistics | 1994 |
| LCP Property Holdings Ltd | Real estate | 2021 |
| LCP Quantum Limited | Transport & logistics | 2008 |
| LCP Storage Limited | Real estate | 2014 |
| LD Building and Joinery Ltd | Construction | 2019 |
| Leatherline Limited | Professional & scientific | 1983 |
| Leholtz Limited | Information & communication | 2026 |
| Leisure Site Limited | Other services | 2020 |
| Leisure Venture Land Limited | Other services | 2020 |
| Lepton Electrical Limited | Construction | 2017 |
| Lesley Violet Ltd | Education | 2022 |
| Lets NOW Order Ltd | Information & communication | 2023 |
| Lewis and Grae Ltd | Real estate | 2025 |
| Lhjr LLP | | 2019 |
| Liam Creative Business Limited | Professional & scientific | 2025 |
| Liberty Atlantic Advisors UK Ltd | Financial services | 2026 |
| Liberty Mind Ltd | Professional & scientific | 2018 |
| Libraco Acquisition Limited | Real estate | 2019 |
| Libraco Finance Limited | Financial services | 2019 |
| Licensed Brands International Limited | Professional & scientific | 2012 |
| Life Fiend Ltd | Other services | 2018 |
| Lifestyle Stories Limited | Professional & scientific | 2022 |
| Lifetime Wills & Trusts Limited | Professional & scientific | 2015 |
| Light Path Limited | Professional & scientific | 2023 |
| Lighting Styles Limited | Wholesale & retail | 2004 |
| Limetree Building Ltd | Construction | 2007 |