| Lindsay Johnson Property Ltd | Households | 2022 |
| Links Scaffolding Group Limited | Construction | 2016 |
| Linton Heath Ltd | Real estate | 2022 |
| Lion Lodge Freehold Management Company Limited | Households | 2009 |
| Liora Power Solutions Limited | Construction | 2025 |
| Lipman Commercial INS Brokers Limited | Administrative & support | 2022 |
| Lipman Holdings Limited | Financial services | 2023 |
| Liquid Flat Roofing Ltd | Construction | 2019 |
| Liquorice Real Estate Limited | Real estate | 2022 |
| List Properties Ltd | Real estate | 2017 |
| Liteworks 2014 Ltd | Administrative & support | 2014 |
| Little Adventurers Montessori (Selby) Ltd | Education | 2025 |
| Little Adventurers Montessori Ltd | Health & social care | 2022 |
| Little Legends Ltd | Education | 2024 |
| Little Rainbow Ltd | Wholesale & retail | 2019 |
| Little Spring Wonders Daycare Nursery Limited | Education | 2007 |
| Little TIN Shed Weddings Ltd | Wholesale & retail | 2018 |
| Little Unicorn Limited | Arts & recreation | 2023 |
| Littlemissflawless Ltd | Wholesale & retail | 2021 |
| Live Love Dance Limited | Arts & recreation | 2017 |
| Lives Transformed Ltd | Health & social care | 2023 |
| Living Huts Ltd | Manufacturing | 2008 |
| LJ Pratley and Co Limited | Extraterritorial | 2000 |
| LJP Professional Services Ltd | Construction | 2014 |
| LJR Heating Ltd | Construction | 2025 |
| LJS Transportation Ltd | Transport & logistics | 2024 |
| LKD Engineering Limited | Professional & scientific | 2011 |
| Lknowles Ltd | Health & social care | 2023 |
| Lkyw Development Ltd | Construction | 2011 |
| LLA Brown & SON Limited | Construction | 1993 |
| Lljr Ltd | Professional & scientific | 2017 |
| LM Electrical Services (Essex) Ltd | Construction | 2024 |
| LMM Consultants Limited | Professional & scientific | 2023 |
| Lmpc Ltd | Other services | 2009 |
| LNE Electrical Contractors Limited | Construction | 2011 |
| Local Asbestos Surveys Ltd | Professional & scientific | 2021 |
| Local Fire Risk Assessments Ltd | Administrative & support | 2021 |
| Lock and Key Housing Limited | Construction | 2024 |
| Lockedin Gyms Ltd | Arts & recreation | 2026 |
| Lodean Limited | Professional & scientific | 2020 |
| Lollipops Cheshunt Limited | Education | 2019 |
| Londinium Elite Chauffeurs Ltd | Transport & logistics | 2026 |
| London & Essex Ground Rents Ltd | Other services | 2021 |
| London 101 Developments Limited | Construction | 2021 |
| London 101 Ltd | Construction | 2014 |
| London Luxury Flowers Ltd | Hospitality | 2024 |
| London Marble Polishing Ltd | Manufacturing | 2020 |
| London Sightseeing Taxi Tours Ltd | Administrative & support | 2024 |
| London Structural Repairs Ltd | Construction | 2014 |
| Londonbim Ltd | Construction | 2024 |
| Long Tale Consulting Ltd | Professional & scientific | 2021 |
| Long's Electrical Services Ltd | Construction | 2023 |
| Longbow Services Management Ltd | Construction | 2026 |
| Lord Jewellers Ltd | Wholesale & retail | 2024 |
| Lorenzo Investments Ltd | Real estate | 2025 |
| Lotus Laser Systems Limited | Extraterritorial | 2018 |
| Love Beauty Training Limited | Education | 2019 |
| Lovedo Ltd | Wholesale & retail | 2025 |
| LOW ALE Limited | Professional & scientific | 2010 |
| Lower Cloister Residents Group Ltd | Households | 2022 |
| Lowtax Investments Limited | Real estate | 2017 |
| Lowtax Limited | Professional & scientific | 1999 |
| LP Search Ltd | Administrative & support | 2025 |
| LPS London Property Services Ltd | Construction | 2025 |
| LPS Scaffolding Ltd | Construction | 2010 |
| LSA Systems Holdings Ltd | Financial services | 2017 |
| LSA Systems Limited | Information & communication | 2011 |
| LSK Services Limited | Professional & scientific | 2002 |
| LSP Property Services Limited | Professional & scientific | 2009 |
| LTG Accountants Limited | Professional & scientific | 1999 |
| LTG Accounting Limited | Extraterritorial | 2023 |
| LTG Billericay Limited | Administrative & support | 2013 |
| LTG Domestic Appliances Limited | Other services | 2023 |
| LTG Nominees Limited | Professional & scientific | 1999 |
| LTG Secretarial Services Limited | Professional & scientific | 1999 |
| LTH Property Services Ltd | Manufacturing | 2015 |
| LTO G Clearance Ltd | Construction | 2025 |
| LTO Property Sales and Management Ltd | Real estate | 2021 |
| LTS Holdings Limited | Financial services | 2022 |
| LTS South East Ltd | Manufacturing | 2022 |
| Lucia Pica Limited | Other services | 2009 |
| Luck and Fuller Bathroom Design Studio Ltd | Construction | 2020 |
| Luckings Properties Limited | Real estate | 2022 |
| Lucy Burt Ltd | Other services | 2026 |
| Lucy Jennings Limited | Professional & scientific | 2019 |
| Luduslabs Ltd | Information & communication | 2025 |
| Lumada Limited | Manufacturing | 2009 |
| Luna Land Investments Limited | Construction | 2018 |
| Luxe Design Studios Ltd | Wholesale & retail | 2021 |
| Luxury Discount Bathrooms Limited | Wholesale & retail | 2023 |
| Luxury Lodge Developments Limited | Hospitality | 2025 |
| Luxury Lodge Estates Company Ltd | Hospitality | 2015 |
| Luxury Lodge Holdings Limited | Financial services | 2025 |
| Luxury Self Catering Resorts.Com Ltd | Hospitality | 2015 |
| Luxx Nails Spa Ltd | Other services | 2025 |
| LV Properties (S E) Limited | Real estate | 2010 |
| Lynwood Limited | Administrative & support | 2009 |
| Lynx Cleaning Limited | Administrative & support | 2000 |
| L’Hexagone Ltd | Wholesale & retail | 2022 |
| M & K Flooring Ltd | Construction | 2011 |