| Landychef Ltd | Hospitality | 2023 |
| Lane Partnerships Limited | Professional & scientific | 2021 |
| Langland Assets LLP | | 2013 |
| Langland Care Limited | Health & social care | 2001 |
| Langland Developments Limited | Extraterritorial | 2013 |
| Langland Holdings Limited | Financial services | 2016 |
| Langland Manor Limited | Construction | 2013 |
| Langmead Consulting Limited | Professional & scientific | 2016 |
| Langmead Limited | Health & social care | 2022 |
| Langton Green Community Sports Association Ltd. | Arts & recreation | 2013 |
| Langton Restaurant Ltd | Hospitality | 2018 |
| Langtonout Limited | Health & social care | 2018 |
| Lansdowne Developments Limited | Real estate | 2026 |
| Lansdowne Manor Limited | Real estate | 2001 |
| Lansdowne Property Consultants Limited | Real estate | 2017 |
| Lansdowne Square Residents Association Limited | Households | 1979 |
| Lansdowne Villa Freehold Limited | Households | 2021 |
| Lanterne Rouge Consulting Ltd | Professional & scientific | 2015 |
| Lanthorne Mews Management Limited | Real estate | 1999 |
| Larkins Services Ltd | Construction | 2022 |
| Larratt & Co (TW) Ltd | Hospitality | 2020 |
| Larry Mayers Leadership and Organisational Development Limited | Professional & scientific | 2013 |
| Laser DOT Templates Ltd | Construction | 2024 |
| Laser Repro 2000 Limited | Manufacturing | 2001 |
| Laser TEC Ltd | Construction | 2013 |
| Late Apex Moto Works Limited | Wholesale & retail | 2025 |
| Lateral Development Limited | Extraterritorial | 2007 |
| Launch PAD Strategies Limited | Construction | 2009 |
| Laura Lindon Consulting Ltd | Professional & scientific | 2018 |
| Laura O'Connor Consulting Limited | Professional & scientific | 2025 |
| Laurie Oppenheim Ltd | Professional & scientific | 2009 |
| Lauriston Family Company Limited | Real estate | 2023 |
| Lavabed Design Limited | Professional & scientific | 2009 |
| Lavanya Infotech Limited | Information & communication | 2014 |
| Lavender Nail & Spa Ltd | Other services | 2025 |
| Law 365 Limited | Professional & scientific | 2014 |
| Lawday Global Commerce Limited | Wholesale & retail | 2024 |
| Lawknox Limited | Financial services | 2013 |
| Lawrence Building & Construction Ltd | Construction | 2020 |
| Lawrence Commercial Services Ltd | Administrative & support | 2024 |
| Lawsons Project Management Limited | Professional & scientific | 2018 |
| Lawtax Limited | Administrative & support | 2000 |
| Lawton's Sustainability Ltd | Professional & scientific | 2025 |
| Lawyers for Liberty | Other services | 2020 |
| Laylee Ltd | Manufacturing | 2026 |
| Lazy J Projects Ltd | Manufacturing | 2011 |
| LB Procurement Limited | Professional & scientific | 2026 |
| LBF Software Ltd | Information & communication | 2025 |
| LC Building Ltd | Construction | 2026 |
| LCH Supervision Ltd | Professional & scientific | 2025 |
| Ldkrail Ltd | Administrative & support | 2025 |
| LDV Construction UK Ltd | Construction | 2015 |
| LE Gonzales Ltd | Professional & scientific | 2026 |
| LE Mistral Wine Company Limited | Wholesale & retail | 2025 |
| LE PUB Scientifique Ltd | Professional & scientific | 2020 |
| Lead Solve Ltd | Professional & scientific | 2021 |
| Leanr ADS Ltd | Information & communication | 2025 |
| Leap Fall Ltd | Information & communication | 2026 |
| Learn Engage Lead Limited | Administrative & support | 2024 |
| Learnedex Limited | Public administration | 2022 |
| Leaves Under Foot Ltd | Information & communication | 2017 |
| Lebs Investments LLP | | 2012 |
| Ledav Properties Ltd | Construction | 2020 |
| LEE 3D Limited | Administrative & support | 2013 |
| LEE Clutch Centre Limited | Wholesale & retail | 2002 |
| LEE Holman Ltd | Information & communication | 2022 |
| Leedham and Company Ltd | Professional & scientific | 2022 |
| Lees' Financial Holdings Limited | Information & communication | 2015 |
| Legacie Developments Ordsall Lane Ltd | Construction | 2020 |
| Legacy Brickwork Ltd | Construction | 2021 |
| Legal and Insurance Services Limited | Financial services | 1989 |
| Legal Tech Services Ltd | Information & communication | 2025 |
| Legatum Property Ltd | Real estate | 2021 |
| Legends Eagle Barbers Ltd | Other services | 2023 |
| Leggett Europe Limited | Administrative & support | 2010 |
| Leigh Roberts Limited | Other services | 2021 |
| Leighton Capital Management Limited | Professional & scientific | 2003 |
| Leighton Hall Management Company Limited | Administrative & support | 2005 |
| Lekki Lagoon Limited | Health & social care | 2010 |
| Lematy Ltd | Information & communication | 2026 |
| Lencrest Partners Ltd | Professional & scientific | 2025 |
| Lending Made Simple Limited | Financial services | 2017 |
| Lenscarefx Ltd | Hospitality | 2004 |
| Lenside Limited | Real estate | 2025 |
| Lenside Management Limited | Real estate | 2025 |
| LEO Mserv Ltd | Construction | 2017 |
| Leonie Wharton Ltd | Professional & scientific | 2019 |
| Lernovatic PVT Ltd | Administrative & support | 2022 |
| Leslie Trevor Limited | Professional & scientific | 2017 |
| Less Deceived Consulting Ltd | Information & communication | 2025 |
| Less EGO Limited | Manufacturing | 2023 |
| Lesters (Tunbridge Wells) Ltd | Construction | 1999 |
| Letterstone Professional Services Limited | Other services | 2026 |
| Lettology Limited | Real estate | 2022 |
| Level Best Solutions Holdings Ltd | Professional & scientific | 2026 |
| Level One Showroom Ltd | Wholesale & retail | 2019 |
| Level Water | Arts & recreation | 2012 |
| Leverage Shares (UK) Limited | Financial services | 2022 |
| Lewin Paro Limited | Professional & scientific | 2026 |
| Lewisprop Ltd | Real estate | 2020 |