| L'Event Ltd | Construction | 2021 |
| L.I.S. (U.K.) Limited | Other services | 2016 |
| L.M. Peacock Contractors Limited | Construction | 2012 |
| L.R.V Couriers Ltd | Transport & logistics | 2015 |
| L22G Limited | Information & communication | 2024 |
| Ladera Limited | Professional & scientific | 1987 |
| Lambert Consultancy Group Ltd. | Administrative & support | 2016 |
| Landhold Properties Limited | Real estate | 1983 |
| Landscape Business AI Systems Ltd | Information & communication | 2025 |
| LAS Enterprises Limited | Other services | 2022 |
| Latestchoice. COM. Ltd | Information & communication | 2000 |
| Latham Hellmers Limited | Wholesale & retail | 1987 |
| Latitude Technical Solutions Ltd | Information & communication | 2018 |
| Lauren Louise Ltd | Other services | 2021 |
| LB Properties Epping Ltd | Real estate | 2023 |
| LBC Investment Holding Ltd | Financial services | 2021 |
| LCB Leaseplans Ltd | Professional & scientific | 2024 |
| LCD Property Holdings Ltd | Real estate | 2026 |
| LCS Facilities Limited | Administrative & support | 2020 |
| LDP Electrical and Sons Ltd | Construction | 2022 |
| LEA Valley Lofts Ltd | Administrative & support | 2017 |
| Leadenhall London Property Ltd | Hospitality | 2026 |
| Lean Business Consulting Limited | Professional & scientific | 2014 |
| Learn and Prosper School Limited | Education | 2022 |
| Learnyogalondon Limited | Arts & recreation | 2013 |
| Leasair & Co LP | | 2012 |
| LEE & Stort Boat Co. Ltd | Transport & logistics | 2012 |
| LEE Family Investments Limited | Real estate | 1960 |
| Lepad Projects Ltd | Construction | 2023 |
| Levenshulme Transport Ltd | Transport & logistics | 2014 |
| LEX Fort Limited | Real estate | 2005 |
| Lexaim Properties Limited | Real estate | 2022 |
| LGB CAD Limited | Administrative & support | 2014 |
| Life Energy and Climate UK Limited | Construction | 2019 |
| Life in the Garden Ltd | Administrative & support | 2011 |
| LIGHTHOUSE-100% Ltd | Construction | 2017 |
| Lilac-May Limited | Other services | 2017 |
| Lillybell Limited | Other services | 2023 |
| Limehouse Funding Limited | Administrative & support | 2017 |
| Link Workspace Ltd | Real estate | 2021 |
| Lint and Kemp Therapy Ltd | Health & social care | 2024 |
| Lionel Smith Compliance Services Limited | Professional & scientific | 2016 |
| Little Drinks Co. (UK) Limited | Manufacturing | 2025 |
| LJP Properties Limited | Real estate | 2021 |
| LK Lighting Limited | Information & communication | 2009 |
| Lleshi Construction Ltd | Construction | 2015 |
| LLM Property Services Ltd | Administrative & support | 2021 |
| Lloyds Legal Wills & Probate Limited | Other services | 2018 |
| LMG (Epping) Limited | Professional & scientific | 2014 |
| LMP Property (Epping) Ltd | Real estate | 2017 |
| LND Signs Limited | Other services | 2018 |
| Logice Sport Ltd | Wholesale & retail | 2025 |
| Logicpress Limited | Extraterritorial | 2001 |
| London Alpacas Ltd | Agriculture & fishing | 2022 |
| London City Waste Clearance Ltd | Water & waste | 2021 |
| London Essex Group Ltd | Extraterritorial | 2018 |
| London Essex Hot Tubs Ltd | Wholesale & retail | 2014 |
| London Essex Outdoor Kitchens Ltd | Construction | 2018 |
| London Essex Outdoor Living Ltd | Wholesale & retail | 2020 |
| London Fields West Management Company Limited | Households | 2025 |
| London Landscapes Limited | Construction | 2007 |
| London Online Store Limited | Wholesale & retail | 2021 |
| London Right Rooms Ltd | Real estate | 2021 |
| London's Hub Ltd | Administrative & support | 2025 |
| Longfield Kennels & Cattery Limited | Hospitality | 2000 |
| Lotus and Lantern Limited | Hospitality | 2025 |
| Louis Moreau London Limited | Manufacturing | 2009 |
| Love 2 Travel Ltd | Administrative & support | 2021 |
| Love Code Less Ltd | Information & communication | 2024 |
| LOVE2CONSULT Ltd | Professional & scientific | 2023 |
| LP Racing Syndicate Ltd | Arts & recreation | 2025 |
| LSG Homes Limited | Real estate | 2022 |
| Lucianstefan Ltd | Construction | 2026 |
| Lucky 13 Music Group Limited | Professional & scientific | 2021 |
| Lucy Pohl Limited | Arts & recreation | 2002 |
| Ludama Ltd | Information & communication | 2026 |
| Lunch Prep Meals Limited | Hospitality | 2021 |
| Luxo 24/7 Tyres Ltd | Wholesale & retail | 2026 |
| Luxo Motors Ltd | Wholesale & retail | 2025 |
| Luxpro Build and Design Ltd | Construction | 2024 |
| Luxpro Construction Limited | Administrative & support | 2010 |
| LV Equestrian Limited | Agriculture & fishing | 2007 |
| LVE Locks and Accessories Ltd | Other services | 2019 |
| LW Media Group Ltd | Arts & recreation | 2026 |
| Lydiam Group Ltd | Information & communication | 2022 |
| M & E Interiors Ltd | Construction | 2015 |
| M&G Logistic Solutions Limited | Transport & logistics | 2016 |
| M&O Management Limited | Real estate | 2023 |
| M. a. Downes Consulting Ltd | Professional & scientific | 2013 |
| M.C Connolly Limited | Construction | 2010 |
| M.P.E. Site Engineering Limited | Professional & scientific | 1998 |
| M11 Construction Limited | Construction | 2006 |
| M2SK Ltd | Hospitality | 2015 |
| Mabe&A Limited | Wholesale & retail | 2022 |
| MAC Plumbing Services Ltd | Construction | 2026 |
| Made by Barton Limited | Professional & scientific | 2024 |
| Made Employment Ltd | Administrative & support | 2020 |
| Made With Volume Ltd | Professional & scientific | 2015 |
| Majestic Property & Estates Limited | Professional & scientific | 1975 |
| Malt & HOP Brewing Supplies Ltd | Wholesale & retail | 2026 |