| Lohan Solutions Ltd | Education | 2024 |
| Lokul Ltd | Wholesale & retail | 2025 |
| Lomas House Management Company Limited | Households | 2012 |
| Lomsach Food Limited | Hospitality | 2025 |
| Lomsach Investment Limited | Financial services | 2022 |
| London & Chelsea Estates Limited | Real estate | 2011 |
| London Luxury Refurbishments Limited | Construction | 2020 |
| London South East, Bromley & Croydon Limited | Other services | 2014 |
| London Town Properties Limited | Real estate | 1962 |
| Longacre Care Home Limited | Health & social care | 2007 |
| Longstraw Bakery Limited | Manufacturing | 2022 |
| Longtail Group Limited | Information & communication | 2026 |
| Look Like Fred Limited | Administrative & support | 2009 |
| Looking for Magic Limited | Information & communication | 2002 |
| Loomah Carpets 2009 Limited | Wholesale & retail | 2009 |
| Loomah Limited | Wholesale & retail | 2001 |
| Lopez Aesthetics Ltd | Health & social care | 2024 |
| Lorabanton Limited | Real estate | 2021 |
| Lorin Limited | Financial services | 2023 |
| Lorwick Chemicals Limited | Wholesale & retail | 1998 |
| Loseth Properties Limited | Real estate | 2012 |
| Lost at Sea Ltd | Information & communication | 2015 |
| Lost Found Studios Ltd | Information & communication | 2015 |
| LOU ROY Skin Ltd | Other services | 2025 |
| Loubou Limited | Other services | 2021 |
| Louis Harrison Ltd | Construction | 2024 |
| Louise Rennison Ltd | Arts & recreation | 2009 |
| Loutro Developments Limited | Other services | 2019 |
| Loutro Holdings Limited | Other services | 2019 |
| Louu Ltd | Information & communication | 2023 |
| Louverly Shutters Limited | Wholesale & retail | 2014 |
| Love for Laser Limited | Other services | 2018 |
| Love Long Limited | Real estate | 2017 |
| Lovelace & Carter Ltd | Information & communication | 2012 |
| Lower Street Management Limited | Households | 1974 |
| Loxley Pharma Consulting Ltd | Professional & scientific | 2017 |
| Loyd Steele Building Ltd | Construction | 2024 |
| LP Group Holding Ltd | Financial services | 2025 |
| LP Group Investments Limited | Financial services | 2025 |
| LP Group Properties Limited | Real estate | 2025 |
| LPA (HR) Limited | Professional & scientific | 2007 |
| LPS Europe Limited | Administrative & support | 2009 |
| LPS Sussex Ltd | Construction | 2020 |
| LQS Healthcare Services Ltd | Health & social care | 2021 |
| LRB Cleaning Services Ltd | Administrative & support | 2014 |
| LS (SE) Ltd | Wholesale & retail | 2020 |
| LS Vehicle Recycling Limited | Wholesale & retail | 2021 |
| LSM Consultants Ltd | Professional & scientific | 2017 |
| LSS Tiling Services Ltd | Construction | 2022 |
| LST Dining Limited | Hospitality | 2023 |
| LT Buff Ltd | Other services | 2024 |
| LTA Property Management Ltd | Real estate | 2022 |
| LTS M&E Services Ltd | Construction | 2019 |
| Lucie-Smith & Co Limited | Professional & scientific | 2006 |
| LUCK3 Ltd | Hospitality | 2010 |
| Luckin Kitchens Limited | Manufacturing | 2017 |
| Luckjiff Ltd | Administrative & support | 2022 |
| Lucky Chickens Films Limited | Information & communication | 2026 |
| Lucurum Limited | Information & communication | 2013 |
| Lucy Campbell Ltd | Arts & recreation | 2021 |
| Lucy Marks Development Limited | Professional & scientific | 2005 |
| Ludbrook Limited | Professional & scientific | 2023 |
| Ludcoclean Ltd | Administrative & support | 2019 |
| Ludisa Recruitment Limited | Administrative & support | 2002 |
| Luff Holdings Hove Limited | Real estate | 2021 |
| Luff Property Group Limited | Professional & scientific | 2021 |
| Lufflur Limited | Professional & scientific | 2022 |
| Luft Training Services Limited | Education | 2010 |
| Luina Limited | | 1977 |
| Luis Abreu Ltd | Professional & scientific | 2020 |
| Luke Avery Ltd | Arts & recreation | 2022 |
| Lullaby Events Ltd | Arts & recreation | 2022 |
| Lumo Electrical Ltd | Construction | 2018 |
| Luna & Quinn Ltd | Information & communication | 2025 |
| Luna Services Ltd | Wholesale & retail | 2022 |
| Luna Sound LLP | | 2025 |
| Lunardi Limited | Hospitality | 2018 |
| Lunaria Sales Ltd | Wholesale & retail | 2024 |
| Lundenwic Ltd | Information & communication | 2023 |
| Luumen Limited | Information & communication | 2013 |
| LUX CUT Ltd | Other services | 2026 |
| LUX Barber Worthing Ltd | Other services | 2023 |
| LUX Interior Services Ltd | Construction | 2015 |
| LWA Technology Ltd | Information & communication | 2017 |
| LY Distribution Ltd | Wholesale & retail | 2025 |
| LYG Invest Ltd | Administrative & support | 2025 |
| Lynch Civil Engineering Limited | Construction | 2008 |
| Lynsay Biss Design Limited | Professional & scientific | 2019 |
| Lynwood Installations Limited | Construction | 2013 |
| Lynwood Strings Limited | Information & communication | 2026 |
| Lyon PUB Company Ltd | Hospitality | 2022 |
| Lyssa Ltd | Information & communication | 2024 |
| M & O Servicing Limited | Manufacturing | 2013 |
| M . R Worthing Ltd | Hospitality | 2023 |
| M a Window Cleaning Limited | Administrative & support | 2006 |
| M B S Properties Ltd | Real estate | 2015 |
| M C Global Engineering Limited | Professional & scientific | 2011 |
| M C Locums Limited | Health & social care | 2013 |
| M Carr Limited | Health & social care | 2019 |
| M F Scarfe Decorators Ltd | Construction | 2019 |