| K G Civils Ltd | Other services | 2019 |
| K&A London Ltd | Wholesale & retail | 2016 |
| K&D Catering 2024 Limited | Hospitality | 2024 |
| K&N Entertainment Ltd | Hospitality | 2024 |
| K-Automation Ltd | Information & communication | 2018 |
| Kabsky Limited | Transport & logistics | 2017 |
| Kaddoo Ltd | Other services | 2016 |
| Kamado JOE UK Limited | Wholesale & retail | 2018 |
| Kane's Wheels & Deals Limited | Wholesale & retail | 2025 |
| Kapodokia Ltd | Other services | 2022 |
| Kared Ltd | Health & social care | 2024 |
| Keel Marine Limited | Professional & scientific | 1962 |
| Kenbridge Limited | Extraterritorial | 1964 |
| Kenekt Solutions (UK) Ltd | Professional & scientific | 2021 |
| Kenwood Appliances Limited | Professional & scientific | 1989 |
| Kenwood International Limited | Professional & scientific | 1989 |
| Khadija's Property Ltd | Real estate | 2025 |
| Khatana Retail Ltd | Wholesale & retail | 2021 |
| Kingscroft School Mews (Bedhampton) Management Company Limited | Real estate | 2016 |
| Kiraz Limited | Other services | 2025 |
| Kirbstone Brickwork Limited | Construction | 2025 |
| Kiswah International Limited | Wholesale & retail | 2026 |
| KJ UK Holdings Limited | Financial services | 2018 |
| KJM Contractors Ltd | Manufacturing | 2010 |
| KJSNAPS95 Ltd | Professional & scientific | 2026 |
| KL Scaffolding Ltd | Construction | 2018 |
| KML Property Limited | Real estate | 2019 |
| KNC Investment Properties Limited | Real estate | 2017 |
| Knight & Knight Holdings Limited | Professional & scientific | 2023 |
| Knight & Knight Property Limited | Real estate | 2023 |
| Knights & Leonard Limited | Hospitality | 2020 |
| Kota Ace Trading Limited | Other services | 2025 |
| Kraft Restaurants Ltd | Hospitality | 2024 |
| Krapmaps Ltd | Information & communication | 2026 |
| Kudashahwe Ltd | Health & social care | 2023 |
| Kuku Shop Limited | Wholesale & retail | 2025 |
| Kuranda UK Limited | Wholesale & retail | 2002 |
| KW Detailing Ltd | Administrative & support | 2023 |
| Kwlo Ltd | Wholesale & retail | 2023 |
| KWS Building Services Ltd | Construction | 2018 |
| L & R Domestic Property Limited | Real estate | 2021 |
| L J T Investments Ltd | Financial services | 2018 |
| L M Tree Surgery Limited | Agriculture & fishing | 2026 |
| L&D Roofing and Leadworks Ltd | Construction | 2025 |
| LA Kattenhorn & Partners (Holdings) Limited | Professional & scientific | 2000 |
| Lady and the Vamp Ltd. | Other services | 2014 |
| Lalizas UK Ltd | Wholesale & retail | 2019 |
| Lambe Analytics Limited | Administrative & support | 2023 |
| Landscart Limited | Administrative & support | 2013 |
| Langston K Limited | Wholesale & retail | 2016 |
| Langstone Adventure Rowing Limited | Arts & recreation | 2012 |
| Langstone Electrical & Kitchen Services Limited | Construction | 2022 |
| Langstone Financial Services Ltd | Financial services | 2021 |
| Larchwood Leasings Limited | Administrative & support | 2013 |
| Larchwood MOT Mobile Service Centre Ltd | Wholesale & retail | 2016 |
| Larchwood MOT Service Centre Ltd | Wholesale & retail | 2012 |
| Larida Limited | Construction | 2016 |
| Laser MED Clinic Limited | Other services | 2024 |
| Lawrence Housing Solutions Ltd | Real estate | 2024 |
| Lawrence I.T. Solutions Limited | Information & communication | 2022 |
| Lawrence Solutions Group Ltd | Financial services | 2024 |
| Lazco Roofing Ltd | Construction | 2025 |
| LCB Services Limited | Administrative & support | 2025 |
| LDR Control Ltd | Professional & scientific | 2014 |
| LDR HV Solutions Limited | Administrative & support | 2026 |
| Leak Trace Plumbing Solutions Ltd | Construction | 2025 |
| LEE Garage Limited | Real estate | 2020 |
| LEE Mark Tigwell Carpentry Ltd | Construction | 2024 |
| Legend Landscapes Ltd | Administrative & support | 2026 |
| Legendhk Ltd | Real estate | 2022 |
| Legendsr Ltd | Information & communication | 2025 |
| Leggett IT Consulting Ltd | Information & communication | 2018 |
| Leigh Park Community Action Team Community Interest Company | Wholesale & retail | 2025 |
| Leigh Park Express Ltd | Hospitality | 2017 |
| Leigh Park Mini Market Ltd | Wholesale & retail | 2026 |
| Lesama Consultings Ltd | Information & communication | 2026 |
| Let's Construct Ltd | Construction | 2025 |
| Level UP Living Limited | Health & social care | 2021 |
| Lewmar Limited | Manufacturing | 1959 |
| Lexicon UK Limited | Education | 2002 |
| Liberty HR Recruitment Ltd | Administrative & support | 2019 |
| Libra Coaching Limited | Professional & scientific | 2007 |
| Linear Fire Consultants Ltd | Public administration | 2024 |
| Little Wild Theatre Ltd | Arts & recreation | 2023 |
| Lloyds Driver Training Ltd | Education | 2015 |
| LNS Consultancy Limited | Information & communication | 2024 |
| Lockerley 1959 Limited | Extraterritorial | 2015 |
| Lockheed Martin Helicopter Company Ltd | Professional & scientific | 2015 |
| Lockheed Martin UK Holdings Limited | Professional & scientific | 1996 |
| Lockheed Martin UK Limited | Professional & scientific | 1989 |
| London Style Network Ltd | Wholesale & retail | 2019 |
| Longmeadow Lettings Ltd. | Real estate | 2015 |
| Louise Pynen Advanced Beauty & Aesthetics Ltd | Other services | 2019 |
| Lpec Fire Consulting Ltd | Professional & scientific | 2013 |
| LTB Systems Ltd | Administrative & support | 2018 |
| LTF Lettings Ltd | Real estate | 2018 |
| LU Gold Ltd | Other services | 2024 |
| Lucky Catch Ltd | Hospitality | 2023 |
| Lucror 268 Ltd | Real estate | 2021 |
| Ludbourne Hall Management Company Limited | Households | 2018 |