| Lexcom Information Systems Ltd | Information & communication | 1973 |
| Lexcom UK Limited | Professional & scientific | 2008 |
| Lexent Partners Ltd | Extraterritorial | 2010 |
| Lexicologist Ltd. | Information & communication | 2020 |
| Lfcm Services Limited | Professional & scientific | 2025 |
| LFM10 Consulting Limited | Information & communication | 2018 |
| LGE Horizon Limited | Information & communication | 2025 |
| Lifecaring Holdings Limited | Professional & scientific | 1994 |
| Lift & Shift 1664 Ltd | Water & waste | 2025 |
| Liftechnic Limited | Professional & scientific | 2004 |
| Liftrig Consulting Ltd | Professional & scientific | 2021 |
| Liftsy UK Ltd | Construction | 2020 |
| Liftx Limited | Wholesale & retail | 1999 |
| Light & Land Limited | Administrative & support | 1995 |
| Lightbeam Consulting Limited | Information & communication | 2024 |
| Lightly Salted Ltd | Information & communication | 2017 |
| Ligs Consultancy Ltd | Construction | 2021 |
| Lilley & Partners Limited | Professional & scientific | 1987 |
| Lillidale Ltd. | Wholesale & retail | 1993 |
| Lily & Co (Dorset) Ltd | Health & social care | 2022 |
| Limbo Limited | Real estate | 2004 |
| Lime Ecosystem Limited | Manufacturing | 2020 |
| Lime Keys Ltd | Professional & scientific | 2017 |
| Limecove Limited | Agriculture & fishing | 1989 |
| Limehurst Consulting Limited | Professional & scientific | 2019 |
| Limeshake Limited | Information & communication | 2018 |
| Limitless Cleaning Ltd | Households | 2021 |
| LIN & Co Property Ltd | Real estate | 2018 |
| Lincoln Beasley P.R. & Marketing Limited | Arts & recreation | 1998 |
| Lindum IT Ltd | Information & communication | 2024 |
| Linfield Developments Limited | Construction | 2008 |
| Link Logistics Services Ltd | Professional & scientific | 2021 |
| Lintrathen Consulting Limited | Professional & scientific | 2019 |
| Linwood Farm Limited | Arts & recreation | 2024 |
| Linwood Sawmill Ltd | Manufacturing | 2014 |
| Lion Change Management Limited | Public administration | 2022 |
| Lionex Logistics Ltd | Transport & logistics | 2016 |
| Lionhunt Ministries | Other services | 2009 |
| Lipco Engineering Limited | Manufacturing | 1992 |
| Lipco Holding Company Limited | Professional & scientific | 2010 |
| Liquid Mango Ltd | Information & communication | 2025 |
| Lisa James Consultancy Ltd | Professional & scientific | 2014 |
| Lishr Limited | Information & communication | 2018 |
| Literary Lovelies Ltd | Manufacturing | 2022 |
| Little Bears Hideaway Ltd | Health & social care | 2018 |
| Little Lives UK Trading Ltd | Other services | 2017 |
| Little Lotus Films Limited | Information & communication | 2015 |
| Little.Bella.Coco Ltd | Manufacturing | 2024 |
| Littoral Risk Ltd | Administrative & support | 2020 |
| Living Healthy Limited | Education | 2019 |
| Living Your Learning Ltd | Education | 2017 |
| LJH Electrical & Training Ltd | Construction | 2024 |
| LJH Graphic Consultants Limited | Professional & scientific | 2000 |
| LKB Commercial Ltd | Professional & scientific | 2023 |
| Llamify Limited | Professional & scientific | 2024 |
| Llannir Ltd | Information & communication | 2018 |
| Llewellin Builders Limited | Construction | 2021 |
| LLJ Services Limited | Professional & scientific | 2025 |
| Lloyd 2000 Ltd | Financial services | 2023 |
| Lloydsconsultancy Limited | Information & communication | 2016 |
| LMB Holdings Ltd | Real estate | 2022 |
| Lmel Consulting Limited | Professional & scientific | 2024 |
| LMG Swart Consulting Ltd | Information & communication | 2019 |
| LMJ Leisure Limited | Arts & recreation | 2019 |
| Lnrc Ltd | Wholesale & retail | 2011 |
| Loader Engineering & Sons Ltd | Manufacturing | 2015 |
| Loadpoint Bearings Limited | Manufacturing | 1988 |
| Lobo Creative Limited | Professional & scientific | 2018 |
| Local IS Best Ltd | Administrative & support | 2025 |
| Localize Gaming Limited | Information & communication | 2023 |
| Locators Limited | Construction | 1985 |
| Lockdown Competitions Limited | Wholesale & retail | 2020 |
| Locke Estates Limited | Real estate | 1998 |
| Locked in Learning Limited | Education | 2026 |
| Lodere Limited | Information & communication | 2025 |
| Lodge Associates Limited | Professional & scientific | 2018 |
| LOE & Lime Ltd | Wholesale & retail | 2025 |
| Logical Paradox Ltd | Information & communication | 2022 |
| Logiccache Ltd. | Information & communication | 2016 |
| Logiemuir Investments Limited | Administrative & support | 2021 |
| Logix Transport Solutions Worldwide Limited | Transport & logistics | 2018 |
| London Claws Limited | Hospitality | 2022 |
| London Four Limited | Professional & scientific | 2019 |
| London Four Property Limited | Real estate | 2021 |
| London House Marketing Limited | Professional & scientific | 2013 |
| Long Lane Building Contractors Ltd | Professional & scientific | 2009 |
| LONGFLEET133 Ltd | Real estate | 2022 |
| Longitude Consulting Ltd | Professional & scientific | 2018 |
| Longmeads Management Limited | | 2007 |
| Longworthy Limited | Energy | 2021 |
| Lonnen Investments Limited | Professional & scientific | 2024 |
| Lonnen Woods Maintenance Company Limited | Households | 1983 |
| Lord Coding Services Limited | Information & communication | 2017 |
| Lord's Tutorial College Ltd | Education | 2013 |
| Lostech Limited | Information & communication | 2022 |
| Lotelle Limited | Other services | 2006 |
| Lothair Consulting Limited | Professional & scientific | 2025 |
| Lotus Seed Limited | Information & communication | 2024 |
| Louise Tope Ltd | Professional & scientific | 2019 |
| Loulouexplores Ltd | Information & communication | 2024 |