| LES Marais Properties Ltd | Real estate | 2025 |
| Levante Agency Limited | Health & social care | 2020 |
| Leverett and Hawley Grand Limited | Administrative & support | 2025 |
| Lewis Marie Limited | Financial services | 2025 |
| Lewis Technical Services Ltd. | Manufacturing | 2022 |
| Leyland Farm (Gawcott) Management Limited | Households | 2009 |
| LF1 Limited | Real estate | 2014 |
| LF2 Limited | Financial services | 2014 |
| Liberty Real Estate Limited | Real estate | 2017 |
| Life Azure Limited | Extraterritorial | 2013 |
| Life-Assure Limited | Financial services | 2020 |
| Lifetime Installations Limited | Construction | 2014 |
| Lifrege Limited | Financial services | 2021 |
| Lightfoot Bros.Limited | Construction | 1968 |
| Lighthouse Technology Holdings Limited | Professional & scientific | 2020 |
| Limbwise Medico-Legal Reporting Ltd | Health & social care | 2026 |
| Limbwise Physiotherapy Ltd | Health & social care | 2025 |
| Lime & Soda Ltd | Professional & scientific | 2023 |
| Limitless Entertainment Ltd | Arts & recreation | 2024 |
| Linda Marshall Consulting Ltd | Professional & scientific | 2013 |
| Linden Village Stores Ltd | Wholesale & retail | 2020 |
| Lions Equipment (UK) Ltd | Manufacturing | 2017 |
| Lions Equipment Limited | Manufacturing | 1985 |
| Liquid Rituals Ltd | Hospitality | 2014 |
| Litenet Ltd | Information & communication | 2019 |
| Little Heartland Financial Limited | Financial services | 2025 |
| Little Heartland Homes Limited | Real estate | 2022 |
| Little Ridge Ltd | Hospitality | 2017 |
| Little Roo's Place Limited | Extraterritorial | 2009 |
| Little Santi Designs Limited | Professional & scientific | 2024 |
| Little Tingewick Access Limited | Households | 2020 |
| Little White Bird Ltd | Extraterritorial | 2021 |
| Lloyd Woodworking Limited | Manufacturing | 2004 |
| Lokys Consultants Ltd | Professional & scientific | 2010 |
| Lola Leyland Ltd | Professional & scientific | 2024 |
| London Refrigeration Ltd | Construction | 2021 |
| London Road (Ashford) Freehold Limited | Administrative & support | 2021 |
| Lone Sound Ltd | Information & communication | 2025 |
| Lorian Delicatessen Ltd | Professional & scientific | 2022 |
| Loring Brown Limited | Real estate | 2007 |
| Louise DE Winter (London) Limited | Professional & scientific | 2016 |
| Louise Hannah Consulting Ltd | Professional & scientific | 2019 |
| Lounovo Ltd | Professional & scientific | 2020 |
| Love & Blooms Limited | Wholesale & retail | 2021 |
| Love Chiropractic Limited | Health & social care | 2022 |
| Love Coco Aesthetics Ltd | Other services | 2021 |
| Love My Competitions Limited | Other services | 2023 |
| Love My Lotto Ltd | Information & communication | 2019 |
| Lovelwood Farm Limited | Agriculture & fishing | 2023 |
| Lovely Paper Stuff Limited | Wholesale & retail | 2022 |
| Lower Wharf (Buckingham) Management Limited | Households | 2002 |
| Loyalprime Limited | Other services | 1990 |
| LR Clinical Solutions Limited | Administrative & support | 2007 |
| LS Physiotherapy Ltd | Health & social care | 2020 |
| LSL Recruitment Ltd | Administrative & support | 2014 |
| LSR Property Service's Ltd | Administrative & support | 2020 |
| LTC Awards Limited | Extraterritorial | 2014 |
| LTM Industries Ltd | Arts & recreation | 2025 |
| Lucid Soft Systems Limited | Information & communication | 2010 |
| Ludcombe Property Limited | Real estate | 2018 |
| Luma Dental Agency Ltd | Health & social care | 2021 |
| Luma Distribution Limited | Wholesale & retail | 2018 |
| Luminor Electrical Services Ltd | Construction | 2026 |
| Lumyx Ltd | Professional & scientific | 2026 |
| Lunar Hub Ltd | Information & communication | 2026 |
| Lunatics Limited | Arts & recreation | 2010 |
| Luxcars London Ltd | Wholesale & retail | 2023 |
| Luxe Dental Clinic Limited | Education | 2021 |
| Lyon Court Associates Limited | Professional & scientific | 1995 |
| M & F Construction Limited | Manufacturing | 2021 |
| M & L Arnott (Contracting) Ltd | Professional & scientific | 2017 |
| M & M (Bucks) Limited | Other services | 2015 |
| M 2 Electrical Services Ltd | Construction | 2018 |
| M 2 Mechanical Ltd | Construction | 2015 |
| M a R Agri Ltd. | Agriculture & fishing | 2007 |
| M Carter Brickwork Limited | Construction | 2007 |
| M J Harris Flooring Ltd | Administrative & support | 2019 |
| M M H Consulting (Europe) Ltd | Professional & scientific | 2008 |
| M&M Small Works Ltd | Construction | 2020 |
| M-Eve Consulter Limited | Administrative & support | 2024 |
| M2 Commercial Property Ltd | Real estate | 2026 |
| M2 Creative Consulting Ltd | Information & communication | 2026 |
| M2 UK Holdings Ltd | Real estate | 2020 |
| M22 Property Company Ltd | Real estate | 2013 |
| Macetrix Ltd | Information & communication | 2024 |
| Macintyre Trees Limited | Professional & scientific | 2015 |
| MAD Mage Ltd | Wholesale & retail | 2025 |
| Made 4 Fighters LLP | | 2013 |
| Made in the Wild Ltd. | Information & communication | 2016 |
| MADE4SPORT Limited | Administrative & support | 2016 |
| Madrin Ltd | Professional & scientific | 2026 |
| Magmanager Content Limited | Professional & scientific | 2020 |
| Mahsl Limited | Other services | 2024 |
| Maid Perfect Limited | Administrative & support | 2006 |
| Maitland James Limited | Professional & scientific | 2020 |
| Maluso Investments Limited | Financial services | 2024 |
| Mangos Tropical Taste Ltd | Hospitality | 2024 |
| Manitowoc Crane Group (UK) Limited | Wholesale & retail | 1984 |
| Manor Carpets & Flooring Ltd | Wholesale & retail | 2019 |
| Manor Farm Barns (Management Company) Limited | Households | 2021 |