| Limitless Academy of Performing Arts Ltd | Education | 2015 |
| Linchpin BIO Consultants Limited | Professional & scientific | 2025 |
| Linchpin BIO Holdings Limited | Financial services | 2026 |
| Linda KAY Limited | Professional & scientific | 2011 |
| Linford Grove Management Company Limited | Households | 2000 |
| Lingfield Herts Ltd | Other services | 2023 |
| Lingley Electronics Limited | Manufacturing | 2006 |
| Link Cctv Holdings Limited | Financial services | 2018 |
| Link Cctv Systems Limited | Administrative & support | 2005 |
| Link Portfolio Management Limited | Administrative & support | 2021 |
| Links Auto Centre Limited | Wholesale & retail | 2025 |
| Lintott Close Management Limited | Real estate | 1980 |
| Lion OUT Limited | Wholesale & retail | 2023 |
| Lionel Eyre Residential Ltd | Administrative & support | 2025 |
| LIS Plumbing Ltd | Construction | 2023 |
| Lisa Investments Limited | Financial services | 2012 |
| Liscarroll Properties Limited | Real estate | 2023 |
| Lishchuk Construction Ltd | Construction | 2025 |
| Lister Tennis Club Limited | Arts & recreation | 2012 |
| Lithx Limited | Wholesale & retail | 2025 |
| Little Coders Ltd | Education | 2021 |
| Little Conkers Limited | Health & social care | 2019 |
| Little Dog VFX Limited | Information & communication | 2015 |
| Little Legs Dog Care Limited | Households | 2017 |
| Little Lumens Radiology Ltd | Health & social care | 2025 |
| Little Malgraves Essex Ltd | Real estate | 2020 |
| Little Tots Childcare Ltd | Other services | 2018 |
| Little Valley Lettings Limited | Real estate | 2023 |
| Littleloosegoose Ltd | Wholesale & retail | 2023 |
| Live More Innovations Ltd | Wholesale & retail | 2025 |
| Livesey Grips Limited | Information & communication | 2023 |
| Living Your Way Ltd | Real estate | 2026 |
| LJ Diamond Drilling & Sawing Ltd | Construction | 2018 |
| LJ Property Holdings Limited | Real estate | 2020 |
| LJ Taylor Recruitment Limited | Administrative & support | 2022 |
| LJB Properties Ltd. | Real estate | 2019 |
| LJS Brickwork Ltd | Construction | 2022 |
| LJS Scaffolding Solutions Ltd | Construction | 2019 |
| LK X Productions Ltd | Administrative & support | 2025 |
| LL Bristol Limited | Real estate | 2025 |
| LL Holdings West Ltd | Financial services | 2025 |
| LL QR Limited | Real estate | 2026 |
| LL West Ltd | Real estate | 2025 |
| LL White Harte Limited | Administrative & support | 2023 |
| Ll-Eb Friar Street Limited | Hospitality | 2010 |
| Lloyd Property Sourcing Ltd | Administrative & support | 2024 |
| Lloyd Williamson Limited | Information & communication | 2005 |
| LM Estates Limited | Hospitality | 2019 |
| LM Logistic (UK) Ltd | Transport & logistics | 2014 |
| LMC Handyman Services Limited | Construction | 2021 |
| LMI Electrical Services Ltd | Construction | 2020 |
| LMM Project Services Ltd | Professional & scientific | 2025 |
| Lmnr Gynaecology Ltd | Health & social care | 2025 |
| LMR Assets Limited | Financial services | 2019 |
| LMR Capital Limited | Administrative & support | 2025 |
| LMR Investments Limited | Hospitality | 2018 |
| LNS Environmental Ltd | Water & waste | 2025 |
| Loca Logistics Ltd | Wholesale & retail | 2017 |
| Local 1 4 U Limited | Information & communication | 2006 |
| Local Pest Control Limited | Administrative & support | 2020 |
| Location Department Limited | Professional & scientific | 2019 |
| Location Secure Ltd | Administrative & support | 2007 |
| LOCK45 Limited | Other services | 2016 |
| Locked INK Ltd | Other services | 2026 |
| Lockleys Manor (Digswell) Management Limited | Households | 1999 |
| Locksley Court Residents Limited | Households | 1991 |
| Locksmiths Near ME Ltd | Other services | 2020 |
| Lodestone Associates Ltd | Other services | 2021 |
| Lodge Farm Contracting Limited | Administrative & support | 2018 |
| Loft Ease Limited | Construction | 2019 |
| Logic LED UK Ltd | Manufacturing | 2024 |
| Logicore Ltd | Information & communication | 2022 |
| Lolascrust Ltd | Manufacturing | 2025 |
| Lollyprop Investments Limited | Other services | 2019 |
| Lombard Accounting Services Limited | Professional & scientific | 2023 |
| London & Herts Gastroenterology Healthcare Ltd | Health & social care | 2022 |
| London & Lisbon Properties Limited | Administrative & support | 1999 |
| London & Somerset Ltd | Real estate | 2013 |
| London and Prime Limited | Real estate | 2022 |
| London Colney Pro Football Club Limited | Wholesale & retail | 2026 |
| London Home Guard Ltd | Administrative & support | 2025 |
| London Kidney Clinic Limited | Health & social care | 2024 |
| London Oral Health Group Ltd | Real estate | 2008 |
| London Paramount Care Ltd | Health & social care | 2019 |
| London Posters Services Limited | Professional & scientific | 2014 |
| London Prime RE Limited | Financial services | 2024 |
| London Road (Block K) Management Company Limited | Households | 1993 |
| London Road (Block M) Management Company Limited | Households | 1991 |
| London Road (Block N) Management Company Limited | Households | 1991 |
| London Road (Block P) Management Company Limited | Real estate | 1992 |
| London Road (Block Q) Management Company Limited | Households | 1991 |
| London Road (West Thurrock) Management Company Limited | Households | 2011 |
| London Road Biggleswade Ltd | Real estate | 2018 |
| London School of Education and Professional Studies Ltd | Information & communication | 2024 |
| London Show Choir Limited | Arts & recreation | 2023 |
| Long and Co (Dentax) Limited | Professional & scientific | 2013 |
| Longacre Garden Maintenance Ltd | Administrative & support | 2018 |
| Longacre Landscaping Ltd | Administrative & support | 2018 |
| Longacre Tree and Garden Services Ltd | Administrative & support | 2016 |
| Longbow Properties Limited | Real estate | 1995 |