| LEE Ventus Limited | Professional & scientific | 2016 |
| Leela Barham Economic Consulting Ltd | Professional & scientific | 2012 |
| Legacy Stage Productions Co. Limited | Arts & recreation | 2025 |
| Leigh Robinson Limited | Construction | 2018 |
| Leisure Client Limited | Arts & recreation | 2009 |
| Lemonhill Properties Ltd | Administrative & support | 2010 |
| Leon Property Company Ltd | Real estate | 2017 |
| Leonards Flooring Ltd | Construction | 2024 |
| LES Clifford Advisory Ltd | Professional & scientific | 2024 |
| Let's TAN (Bexleyheath) Ltd | Other services | 2022 |
| Lewis of London Limited | Extraterritorial | 2013 |
| LEX Regulatory Ltd | Real estate | 2017 |
| Lexpol (U.K.) Limited | Manufacturing | 1989 |
| Lfer Limited | Energy | 2025 |
| LGC Waste Ltd | Financial services | 2020 |
| LGD Farming Limited | Construction | 1998 |
| LH Strategic Finance Ltd | Professional & scientific | 2026 |
| Liberty House Management Company Limited | Real estate | 2011 |
| Libra Mechanical Services Limited | Construction | 2014 |
| Lidge Interiors Ltd | Manufacturing | 2015 |
| Lifesaver Skills Limited | Education | 2025 |
| Lifezone Health Limited | Extraterritorial | 2025 |
| Lightbulb Moments Coaching and Events Limited | Other services | 2015 |
| Lighttrapper Photography Limited | Professional & scientific | 2011 |
| Lilford Squire Ltd | Information & communication | 2016 |
| Lily & Lace Ltd | Health & social care | 2025 |
| Limegreendreams Ltd | Professional & scientific | 2010 |
| Limehill Properties Ltd | Administrative & support | 2010 |
| Limestone Oak Ltd | Construction | 2024 |
| Limitless Academy Franchise Limited | Education | 2025 |
| Limitless Lithium Limited | Wholesale & retail | 2026 |
| Limitlessness Ltd | Education | 2022 |
| Line Mark (UK) Limited | Manufacturing | 1995 |
| Linenova Home Ltd | Wholesale & retail | 2026 |
| Linhope Consulting Limited | Professional & scientific | 1999 |
| Link Creators Club Ltd | Professional & scientific | 2026 |
| Litlington Management Company Limited | Administrative & support | 2006 |
| Little Barrington Hall Farms Limited | Agriculture & fishing | 1997 |
| Littlefair Developments Ltd | Real estate | 2026 |
| Lizian Hitchin Ltd | Financial services | 2016 |
| LJB Limited | Real estate | 2022 |
| LMC Accounts Ltd | Professional & scientific | 2024 |
| LMC Taverns Limited | Hospitality | 2024 |
| LMS Vehicle Solutions Ltd | Wholesale & retail | 2014 |
| Local Scaffolding Ltd | Construction | 2025 |
| Lockey Digital UK Ltd | Wholesale & retail | 1982 |
| Lodge Plumbing & Building Supplies Ltd | Wholesale & retail | 2021 |
| Lodge Plumbing & Heating Services Ltd | Construction | 2016 |
| Lokono AI Ltd | Information & communication | 2025 |
| Lombari Holdings Limited | Administrative & support | 1994 |
| London Cabinet Makers Ltd | Manufacturing | 2010 |
| London Heritage Roofing Ltd | Construction | 2025 |
| London Supply Teachers Ltd | Administrative & support | 2016 |
| Lone Ranger Films Limited | Information & communication | 2014 |
| Long Lane Fowlmere Management Company Limited | Real estate | 2018 |
| Longmead Homes Limited | Construction | 1998 |
| Lonsdale Place Management Limited | Households | 1981 |
| Lonsdale Venture Group Limited | Wholesale & retail | 2024 |
| Loreto Property Developments Ltd | Construction | 2025 |
| Lotus Gardens Herts Ltd | Hospitality | 2023 |
| Love Aviation Ltd | Professional & scientific | 2025 |
| Love YOU Burlesque Ltd | Arts & recreation | 2016 |
| Lower Manor Farm Limited | Extraterritorial | 2011 |
| Lucy Mays Cleaning Services Ltd | Administrative & support | 2018 |
| Lulu Transport Ltd | Transport & logistics | 2026 |
| Lunarixs Enterprises Ltd | Manufacturing | 2025 |
| Luui's Pride Limited | Health & social care | 2025 |
| Luxury Student Homes Ltd | Real estate | 2012 |
| Lyngham Court Management Limited | Households | 1982 |
| Lynn Brett Fcma Limited | Professional & scientific | 2024 |
| Lyric Lounge Studio Ltd | Information & communication | 2024 |
| M & a Dryliners Limited | Construction | 1989 |
| M & a Hearn Limited | Health & social care | 2012 |
| M & D Design Limited | Manufacturing | 2025 |
| M & M Entertainments Ltd | Hospitality | 2017 |
| M a Motors (ST. Neots) Limited | Wholesale & retail | 2011 |
| M Blenkley Consulting Ltd | Administrative & support | 2014 |
| M Groundworks Limited | Construction | 2018 |
| M J Group Ltd | Construction | 2017 |
| M K Companies Limited | Professional & scientific | 2009 |
| M P Bischoff Ltd | Professional & scientific | 2018 |
| M R Carter & Sons Limited | Extraterritorial | 2010 |
| MA Johnson Properties Ltd | Real estate | 2024 |
| MA Khin IP Ltd | Administrative & support | 2024 |
| Macduff Properties Limited | Real estate | 2014 |
| Mace Property Maintenance Ltd | Administrative & support | 2021 |
| Machine Soul Collective Ltd | Information & communication | 2025 |
| Machine Tool Maintenance (Cambridge) Limited | Administrative & support | 2000 |
| Macpherson Training & Retreats Ltd | Hospitality | 2026 |
| Made MAN Limited | Other services | 2025 |
| Magnimopus Limited | Professional & scientific | 2015 |
| Maillica Toys Ltd | Extraterritorial | 2023 |
| Main Plumbing Limited | Construction | 2021 |
| Maison Sandra Ltd | Administrative & support | 2025 |
| Maitlands Limited | Construction | 1982 |
| Malina Ciuca Ltd | Manufacturing | 2024 |
| Mallula Limited | Wholesale & retail | 2015 |
| Management & Support Processes Ltd | Administrative & support | 2017 |
| Mango's Group Ltd | Hospitality | 2021 |
| Mannawell Limited | Health & social care | 2016 |