| Livingston Visionplus Limited | Wholesale & retail | 1989 |
| Lizard NDE Limited | Professional & scientific | 2012 |
| Lj's Communities Ltd | Information & communication | 2024 |
| LJM Trading Ltd | Financial services | 2025 |
| LJR Estates Limited | Real estate | 2017 |
| LJS Windows Ltd | Construction | 2019 |
| LJW Project Management Services Ltd | Professional & scientific | 2024 |
| LK Hris Ltd | Administrative & support | 2023 |
| Llanelli Sand Dredging Limited | Mining & quarrying | 1938 |
| Llangefni Specsavers Limited | Wholesale & retail | 2026 |
| Llanishen Specsavers Limited | Wholesale & retail | 2016 |
| LLC Limited | Extraterritorial | 2016 |
| Lloyds Environmental Waste Management Limited | Extraterritorial | 1993 |
| LM & AM Property Ltd | Real estate | 2018 |
| LM Law Consultancy Limited | Professional & scientific | 2016 |
| LM Psychotherapy Services Ltd | Health & social care | 2023 |
| LM1 Management Ltd | Real estate | 2016 |
| Lmds Architectural Limited | Professional & scientific | 2010 |
| Lmglservices Ltd | Transport & logistics | 2025 |
| Lmpg Investments Ltd | Administrative & support | 2023 |
| LMS Solutions Ltd | Administrative & support | 2023 |
| Lmsuk (Music) Ltd | Arts & recreation | 2021 |
| LMT Properties Ltd | Real estate | 2025 |
| LMV Management Company Limited | Households | 1992 |
| LMX Bidco Limited | Financial services | 2024 |
| LMX Holdco Limited | Financial services | 2024 |
| LNA Projects Limited | Professional & scientific | 2010 |
| Local Company Services Limited | Other services | 2017 |
| Location Charlie Ltd | Information & communication | 2016 |
| Lockbox Security Limited | Information & communication | 2026 |
| Locks Heath Builders Ltd | Construction | 2022 |
| Locksash Company | Financial services | 2018 |
| Locum Logic Limited | Health & social care | 2008 |
| Locum Nurse Ltd | Administrative & support | 2025 |
| Loft Access Solutions Ltd | Construction | 2024 |
| Loguin Ltd | Information & communication | 2010 |
| LOK Medpm Ltd | Administrative & support | 2025 |
| London 4 Domiciliary Specsavers Limited | Wholesale & retail | 2014 |
| London 8 Domiciliary Specsavers Limited | Wholesale & retail | 2013 |
| London Colney Specsavers Limited | Wholesale & retail | 2018 |
| London Magnolia Limited | Information & communication | 2025 |
| London Southern Logistics Ltd | Transport & logistics | 2025 |
| London Wall Visionplus Limited | Wholesale & retail | 2004 |
| Lone Star Global Ltd | Construction | 2019 |
| Longbridge Specsavers Hearcare Limited | Wholesale & retail | 2025 |
| Longbridge Specsavers Limited | Wholesale & retail | 2016 |
| Longcross Limited Partnership | | 2021 |
| Longdon Hall School Limited | Education | 2010 |
| Longshaw Developments Limited | Real estate | 2011 |
| Longton Specsavers Hearcare Limited | Wholesale & retail | 2018 |
| Longton Specsavers Limited | Wholesale & retail | 2002 |
| Longwater Specsavers Limited | Wholesale & retail | 2019 |
| Lopez Lettings Limited | Real estate | 2019 |
| LOR Ltd | Information & communication | 2023 |
| Lord Street Specsavers Limited | Wholesale & retail | 1992 |
| Lord Street Visionplus Limited | Wholesale & retail | 1992 |
| Lordhair Co., Ltd | Wholesale & retail | 2016 |
| Lostballsfound Ltd | Wholesale & retail | 2025 |
| Lostit Parts N' Accessories Limited | Wholesale & retail | 2011 |
| Lotus Family Law Limited | Professional & scientific | 2022 |
| Loughborough Specsavers Hearcare Limited | Wholesale & retail | 2013 |
| Loughton Specsavers Limited | Wholesale & retail | 2002 |
| Louiscoco Ltd | Wholesale & retail | 2024 |
| Louise Hart Ltd | Health & social care | 2025 |
| Louleighs Sweet Treats Ltd | Hospitality | 2025 |
| Loumax Services Ltd | Professional & scientific | 2018 |
| Louth Specsavers Hearcare Limited | Wholesale & retail | 2017 |
| Louth Specsavers Limited | Wholesale & retail | 2004 |
| Louth Visionplus Limited | Wholesale & retail | 2004 |
| Love Compliance Limited | Professional & scientific | 2018 |
| Love My Lights Limited | Administrative & support | 2026 |
| Loveday Hampshire Limited | Other services | 2013 |
| Lovett Investment Properties Ltd | Real estate | 2022 |
| LOW Carbon Recruitment Ltd | Administrative & support | 2021 |
| LOW Hall Specsavers Limited | Wholesale & retail | 2019 |
| Lowes Financial Management Limited | Financial services | 1973 |
| Lowes Group Limited | Professional & scientific | 1989 |
| Lowes Investment Management Limited | Financial services | 2000 |
| Lowes Quantum Limited | Financial services | 2021 |
| Lowestoft Specsavers Limited | Wholesale & retail | 1995 |
| Lowestoft Visionplus Limited | Wholesale & retail | 1995 |
| Lowtide Coffee Co. Ltd | Manufacturing | 2020 |
| LP Construction Civils Limited | Construction | 2025 |
| LP Property Services Ltd | Real estate | 2023 |
| LQ III Propco 1 Ltd | Real estate | 2025 |
| LS Decorating and Tiling Services Limited | Construction | 2018 |
| LS3 Properties Ltd | Real estate | 2023 |
| LSH Decorating Services Ltd | Construction | 2018 |
| Lsmc Properties Limited | Real estate | 2025 |
| LTA Real Estate Limited | Real estate | 2022 |
| LTJ Primekey Properties Ltd | Real estate | 2025 |
| LTT Property Ltd | Real estate | 2019 |
| Luan Consultancy Ltd | Professional & scientific | 2012 |
| Lubega Limited | Administrative & support | 2012 |
| Lucid Edge Group Ltd | Information & communication | 2023 |
| Lucidum Data Science Limited | Professional & scientific | 2013 |
| Lucious Lets Limited | Hospitality | 2025 |
| Lucky Crab Limited | Hospitality | 2017 |
| Lucy MAI Harwood Limited | Professional & scientific | 2013 |
| Lucy Wiltshire Consulting Ltd | Professional & scientific | 2021 |