| LBP Data Solutions Ltd | Information & communication | 2020 |
| Lckicks Ltd | Wholesale & retail | 2025 |
| LD Import Group Ltd | Wholesale & retail | 2021 |
| LDN Utilities Ltd | Energy | 2019 |
| Lead Givers International Ltd | Information & communication | 2023 |
| Leading Solutions Southern Limited | Construction | 2013 |
| Leaina Ltd | Wholesale & retail | 2025 |
| Learner Driving Guide Ltd | Education | 2017 |
| Leaside Close Freehold Limited | Households | 2020 |
| Ledlites Ltd | Wholesale & retail | 2011 |
| LEE Maisey Consulting Ltd | Professional & scientific | 2019 |
| Lee-Lewis Commercial Ltd | Real estate | 2025 |
| Lees Property and Design Ltd | Professional & scientific | 2011 |
| Leessa Limited | Manufacturing | 2017 |
| Leif Community Interest Company | Education | 2026 |
| Leijgrave Fire Protection Ltd | Administrative & support | 2024 |
| Lemco Acquisitions Limited | Real estate | 2023 |
| Lemsford Building & Construction Ltd | Construction | 2013 |
| Lemsford Metal Products (1982) Limited | Manufacturing | 1982 |
| LEVEL9 Talent Limited | Information & communication | 2025 |
| Levell Games Limited | Manufacturing | 2025 |
| Levona Group Ltd | Wholesale & retail | 2025 |
| LG Properties (WGC) Limited | Real estate | 2001 |
| Lgdn Bidco Limited | Financial services | 2019 |
| Lgdn Cross Stream Limited | Health & social care | 2022 |
| Lgdn Finco Limited | Financial services | 2019 |
| Lgdn Midco Limited | Financial services | 2019 |
| Lgdn PROPCO1 Limited | Real estate | 2021 |
| Lgdn Topco Limited | Financial services | 2019 |
| LH Restaurant Ltd | Hospitality | 2023 |
| LHWGC1 Ltd | Administrative & support | 2025 |
| Liberecas Limited | Professional & scientific | 2020 |
| Lifesight Limited | Financial services | 2015 |
| Lighthawk Ltd | Professional & scientific | 2009 |
| Lightning Cleaning Solutions Ltd | Administrative & support | 2025 |
| Lily Interiors Limited | Construction | 2026 |
| Lindsey Celebrant Ltd | Arts & recreation | 2017 |
| Linevie Services Ltd | Construction | 2015 |
| Lingwood Plastering Limited | Construction | 2008 |
| Link Design Development Ltd | Administrative & support | 2010 |
| Lionservices Ltd | Construction | 2013 |
| Liquid Imaging Limited | Information & communication | 2007 |
| Liquidsun Ltd | Manufacturing | 2016 |
| Lisdrive Ltd | Transport & logistics | 2023 |
| Lithium Grid Limited | Energy | 2026 |
| Little Explorers Day Nursery Ltd | Education | 2005 |
| Little Garden Day Nurseries Limited | Health & social care | 1988 |
| Little Monster Sites Limited | Information & communication | 2003 |
| Little Munchkins Montessori Ltd. | Education | 2015 |
| Little Robins Pre-School Limited | Education | 2014 |
| Live Chat Factory Ltd | Professional & scientific | 2020 |
| Live in Peace Ltd | Other services | 2019 |
| Live Successfully Limited | Arts & recreation | 2010 |
| Livingspring Consult Ltd | Health & social care | 2025 |
| Livingspring Homes Limited | Real estate | 2023 |
| Livingsprings Care Limited | Administrative & support | 2023 |
| Llama Scenes Ltd | Construction | 2022 |
| Llch Welwyn Ltd | Hospitality | 2017 |
| LLR Services Ltd | Extraterritorial | 2019 |
| LM Domestic Ltd | Administrative & support | 2020 |
| LMJ Electrical Contractors Ltd | Construction | 2019 |
| Load OFF Your Back Ltd | Administrative & support | 2011 |
| Local Electricians Hertfordshire Ltd | Energy | 2019 |
| Locationtime Services Ltd | Information & communication | 2025 |
| Lockdownsoft Technology Ltd | Wholesale & retail | 2024 |
| Logic 78 Limited | Professional & scientific | 2011 |
| London Football Catering Ltd | Hospitality | 2010 |
| London Furniture Spraying Ltd | Other services | 2015 |
| London Joinery Services Ltd | Construction | 2018 |
| London Road Motors Ltd | Wholesale & retail | 2018 |
| Lone and Grey Outfitters Ltd | Wholesale & retail | 2020 |
| Longcroft Luxury Cat Hotels Ltd | Hospitality | 2011 |
| Longcroft Mortgages Ltd | Financial services | 2024 |
| Longwave Media Limited | Information & communication | 2015 |
| Lord M'S Limited | Hospitality | 2016 |
| Lornmark (Perth) Limited | Administrative & support | 2005 |
| Lote.Barbers Ltd | Other services | 2026 |
| Lotus Clinic Hitchin Ltd | Other services | 2026 |
| Loudpack Construction Ltd | Construction | 2022 |
| Loui GAS Services Ltd | Construction | 2026 |
| Loui Plumbing Services Ltd | Construction | 2026 |
| Louise FW Ltd | Manufacturing | 2025 |
| Love Dove Generation Limited | Wholesale & retail | 2019 |
| Lovejoy Event Hire Limited | Administrative & support | 2024 |
| Lovejoy Solutions Limited | Administrative & support | 2024 |
| Lovelectrical Services Limited | Construction | 2016 |
| LPD Equestrian Limited | Extraterritorial | 2020 |
| LS Lexia Ltd | Professional & scientific | 2021 |
| Lssl Ltd | Financial services | 2023 |
| LT Air Conditioning Limited | Construction | 2026 |
| LT Art Management Ltd | Wholesale & retail | 2026 |
| Luchi Ltd | Real estate | 2025 |
| Lucy BEE Ltd | Manufacturing | 2012 |
| LUK Autos AL7 Ltd | Wholesale & retail | 2020 |
| LUK Export Ltd | Wholesale & retail | 2024 |
| Luk-Al Ltd | Construction | 2014 |
| Luma De'Ceu Ltd | Information & communication | 2022 |
| Luma KI Productions Limited | Information & communication | 2017 |
| Lunedale Limited | Administrative & support | 1992 |
| Luxe Distribution Limited | Administrative & support | 2014 |