| Lewis Denley Limited | Professional & scientific | 2017 |
| Lexi Apps Limited | Information & communication | 2013 |
| LEY Consultants Limited | Other services | 2021 |
| LGM Insurance Services LLP | | 2009 |
| Libertei PA Ltd | Administrative & support | 2015 |
| Liberty Health Clinics Ltd | Health & social care | 2020 |
| Liberty Street Properties Ltd | Real estate | 2024 |
| Life Cycle Financial Planning Ltd | Financial services | 2007 |
| Life Education Ltd | Education | 2023 |
| Lifetime Financial Management & Planning Limited | Extraterritorial | 2024 |
| Lifetime Management & Planning Limited | Professional & scientific | 2000 |
| Lifewave Sales & Marketing Ltd | Wholesale & retail | 2008 |
| Lifsense Ltd | Manufacturing | 2024 |
| Lift IT Solutions Ltd | Transport & logistics | 2020 |
| Lightning Social Ventures Ltd | Information & communication | 2020 |
| Lightscale Tech Ltd | Information & communication | 2016 |
| Lightyear Assets Limited | Real estate | 2018 |
| Lilikat Limited | Hospitality | 2022 |
| Lillypond Healthcare Services Limited | Health & social care | 2011 |
| Lime Kiln Investments Limited | Real estate | 2026 |
| Limitless Prospects Ltd | Professional & scientific | 2020 |
| Lincz Free Shop CIC | Other services | 2025 |
| Linda Meredith Skin Care Limited | Wholesale & retail | 2003 |
| Linden House Properties Limited | Real estate | 2009 |
| Lindfield Loyalty Limited | Professional & scientific | 2025 |
| Lindley House (Felixstowe) Management Company Limited | Households | 2019 |
| Line UP Aviation Limited | Administrative & support | 2001 |
| Line UP Limited | Administrative & support | 1991 |
| Link Minibuses Ltd | Transport & logistics | 2019 |
| Linked AP Ltd | Professional & scientific | 2021 |
| Linked Property Solutions Ltd | Real estate | 2025 |
| Linked UK Investments Ltd | Construction | 2020 |
| Lintott Gardens Residents Company Limited | Professional & scientific | 1987 |
| Lion Co Construction Limited | Construction | 2025 |
| Lion Pack Ltd | Administrative & support | 2024 |
| Lion Property Services and Reports Ltd | Households | 2025 |
| Lion Rock London Property Management Limited | Construction | 2024 |
| Lions, Tygas and Bairs Ltd | Professional & scientific | 2024 |
| Liquid Language Ltd | Health & social care | 2020 |
| Liquorice Productions Limited | Administrative & support | 2011 |
| Lismore Instruments Limited | Manufacturing | 1986 |
| Lispro Ltd | Manufacturing | 2009 |
| Litalist Ltd | Wholesale & retail | 2020 |
| Litebyte Media Ltd | Information & communication | 2024 |
| Lito Design Ltd | Wholesale & retail | 2023 |
| Liton Ltd | Wholesale & retail | 2024 |
| Little Bridge Search Limited | Administrative & support | 2021 |
| Little Brown Bears Ltd | Manufacturing | 2025 |
| Little Capital Ltd | Real estate | 2024 |
| Little Editions & Co Limited | Wholesale & retail | 2026 |
| Little Jester Productions Ltd | Arts & recreation | 2025 |
| Little Notes Franchising Limited | Education | 2014 |
| Little Notes Horsham Ltd | Education | 2008 |
| Little Notes Ltd | Education | 2014 |
| Little Oak Energy Ltd | Professional & scientific | 2012 |
| Little Rowfold Doggy Daycare Ltd | Other services | 2025 |
| Little Vintage TIN Ltd | Hospitality | 2024 |
| Littlefords Pilates Ltd | Arts & recreation | 2025 |
| Littleworth Open Space Limited | Real estate | 2013 |
| Live at the Drill Ltd | Arts & recreation | 2026 |
| Live&Loveit Ltd. | Health & social care | 2017 |
| Liveco Homes Ltd | Construction | 2018 |
| Living Architects Limited | Professional & scientific | 2000 |
| Living Your Passion Ltd | Professional & scientific | 2024 |
| Lizard Properties (Sussex) Limited | Administrative & support | 2005 |
| Lizzie Tulip Limited | Administrative & support | 2012 |
| Ljbirch Management Ltd | Administrative & support | 2026 |
| LJL Groundwork’S and Landscaping Ltd | Construction | 2025 |
| LJT Ventures Ltd | Professional & scientific | 2023 |
| LK Trade Limited | Information & communication | 2012 |
| LKA Bath Property Ltd | Real estate | 2018 |
| LKR Enterprises Limited | Wholesale & retail | 2011 |
| LKR Group Ltd | Real estate | 2026 |
| Lloyd Digital UK Ltd | Information & communication | 2026 |
| Lloyd Williams Property Ltd | Real estate | 2021 |
| LM Business Partnering Limited | Professional & scientific | 2014 |
| LMB Plumbing Ltd | Construction | 2026 |
| LMC Performance Ltd | Wholesale & retail | 2020 |
| LMH Management Ltd | Professional & scientific | 2022 |
| LMP Electricals Limited | Construction | 2006 |
| LMR Consultancy Ltd | Professional & scientific | 2024 |
| Lmsc (Knightsbridge) Limited | Wholesale & retail | 2025 |
| LN Healing Ltd | Health & social care | 2016 |
| LNF Recycling Limited | Water & waste | 2025 |
| LOC Limited | Transport & logistics | 2005 |
| Lock House Partners LLP | | 2025 |
| Lockwell Trustees Limited | Professional & scientific | 1965 |
| Locum Relief Ltd | Administrative & support | 2008 |
| Loesche Energy Systems Limited | Manufacturing | 2006 |
| Logic 1ST Limited | Information & communication | 2003 |
| Logistics Development UK Limited | Administrative & support | 1999 |
| Logitheque Limited | Information & communication | 2020 |
| Lokisoft Ltd | Information & communication | 2021 |
| Londinium Human Resources Ltd | Professional & scientific | 2018 |
| London Country Tours Limited | Administrative & support | 2011 |
| London English Tutors Limited | Education | 2008 |
| London Shortstays Limited | Administrative & support | 2019 |
| London Soundproofing Pro Ltd | Construction | 2019 |
| London Transport International Limited | Manufacturing | 2018 |
| London Wine Exchange Limited | Extraterritorial | 2011 |