| Longwood Copse Residents Limited | Households | 2015 |
| Loova Marketing Ltd | Wholesale & retail | 2023 |
| Loranridge Limited | Manufacturing | 1988 |
| Lorena Accountants Ltd | Professional & scientific | 2018 |
| Lorimer-O'Neill Grab & Groundworks Ltd | Construction | 2024 |
| Lorita Interprises Limited | Health & social care | 2015 |
| Lost in I.T Limited | Information & communication | 2006 |
| LOT Property Developments Ltd | Construction | 2020 |
| Lotex PD Limited | Real estate | 2019 |
| Lotus Lubes Limited | Financial services | 2024 |
| Louise Laing Fashion Consultancy Limited | Professional & scientific | 2015 |
| Louise Sykes Styling Limited | Arts & recreation | 2014 |
| Louvieri Ltd | Wholesale & retail | 2023 |
| Lou’S Luxuries Ltd | Wholesale & retail | 2026 |
| Lovat Parks 2 Limited | Arts & recreation | 2021 |
| Lovat Parks 3 Limited | Arts & recreation | 2026 |
| Lovat Parks Limited | Hospitality | 2017 |
| Love Cleaners Limited | Administrative & support | 2026 |
| Love Creates | Information & communication | 2002 |
| Love Grabs & Groundworks Ltd | Transport & logistics | 2025 |
| Love Recovery & Storage Ltd | Transport & logistics | 2026 |
| Love Your Skin London LLP | | 2010 |
| Loving Care Healthcare Services Ltd | Health & social care | 2016 |
| LOW Energy Systems Limited | Energy | 2013 |
| LOX Homes Limited | Real estate | 2024 |
| Loyalty Properties Ltd | Construction | 2026 |
| LP Sports LLP | | 2019 |
| LP Trans Ltd | Transport & logistics | 2023 |
| LPS Property Refurbishments Ltd | Construction | 2025 |
| LQS Services Limited | Construction | 2017 |
| LR Drainage Limited | Construction | 2023 |
| LR Procurement Services Limited | Professional & scientific | 2026 |
| Lray Consulting Limited | Administrative & support | 2014 |
| LS Ferry Trans Sped Ltd | Transport & logistics | 2022 |
| LS Motors Services Ltd | Other services | 2016 |
| Lsab Consulting Ltd | Real estate | 2020 |
| LSF Electrical Services Ltd | Construction | 2012 |
| LSL Access Ltd | Professional & scientific | 2023 |
| LSS London Limited | Administrative & support | 2019 |
| Luca Swift Transport Ltd | Transport & logistics | 2018 |
| Lucagabriel Limited | Transport & logistics | 2019 |
| Lucid Books Limited | Professional & scientific | 2014 |
| Lucille Jenner Services Limited | Hospitality | 2019 |
| Lucky Sky Limited | Hospitality | 2024 |
| Ludlow Capital Limited | Financial services | 2023 |
| Ludwick Limited Limited | Professional & scientific | 2024 |
| Lugz African Mart Ltd | Wholesale & retail | 2024 |
| Luis Management Services Ltd | Real estate | 2022 |
| Lukasz Construction Ltd | Construction | 2009 |
| Lukasz Halka Ltd | Transport & logistics | 2016 |
| Lulu's Kitchen and Events Services Ltd | Other services | 2023 |
| Lumina Healthplus Ltd | Health & social care | 2015 |
| Lumina Technologies Ltd | Information & communication | 1998 |
| Lumino Commercial Mortgages Ltd | Financial services | 2025 |
| Lumino Land Ltd | Real estate | 2025 |
| Lumino Mortgages Limited | Financial services | 2025 |
| Lumos Financial Limited | Financial services | 2020 |
| Lunarc Build & Design Ltd | Construction | 2025 |
| Lund Farm (Ulverston) Management Company Limited | Households | 2019 |
| Lungu Construction Limited | Construction | 2024 |
| Lupa Collective Ltd | Administrative & support | 2025 |
| Lutus Constructions Ltd | Construction | 2019 |
| Lutus Contracts Ltd | Construction | 2021 |
| LUV Cocktails Ltd | Hospitality | 2010 |
| LUX Property Maintenance Ltd | Construction | 2025 |
| LUX Secure Doors Ltd | Wholesale & retail | 2023 |
| Luxal Group Ltd | Construction | 2026 |
| Luxe Bathroom Specialists Limited | Construction | 2020 |
| Luxe Locks & Braids Ltd | Other services | 2025 |
| Luxmotion Events UK Ltd | Administrative & support | 2025 |
| Luxora Chocolate Ltd | Wholesale & retail | 2024 |
| LUXURY6868 Ltd | Other services | 2025 |
| Luxx Airport Transfers Ltd | Transport & logistics | 2023 |
| Lvcci Limited | Professional & scientific | 2019 |
| LVJ Homes Ltd | Real estate | 2020 |
| LVT Beauty Products Ltd | Other services | 2022 |
| Lychee Game Labs Ltd | Information & communication | 2015 |
| Lychgate Residents (Bovingdon) Limited | Households | 1973 |
| Lyde View Residents Management Company Limited | Households | 2021 |
| Lyonclad Security Ltd | Administrative & support | 2025 |
| M & H Tech Solutions Limited | Wholesale & retail | 2025 |
| M & K Carpentry Limited | Construction | 2009 |
| M & Mags Ltd | Construction | 2026 |
| M & N Rigging Services Ltd | Construction | 2017 |
| M & P Paving Contractors Ltd | Administrative & support | 2012 |
| M a Residential Solutions Ltd | Construction | 2019 |
| M Cotton Limited | Construction | 2008 |
| M D K Building Contractors Limited | Construction | 1998 |
| M Davis Consulting Ltd | Professional & scientific | 2026 |
| M Greaves Construction Limited | Construction | 2006 |
| M J G SET Projects Ltd | Information & communication | 2022 |
| M J M Vehicle Services Ltd | Wholesale & retail | 2015 |
| M J O Upholsterers Ltd | Manufacturing | 2019 |
| M J Waldron Services Limited | Wholesale & retail | 2019 |
| M N Enterprise Ltd | Real estate | 2026 |
| M N R Plumbing and Heating Ltd | Construction | 2024 |
| M P Electrical Installations Ltd | Construction | 2018 |
| M T Car and Vans Ltd | Wholesale & retail | 2023 |
| M T Paving Limited | Construction | 2008 |
| M&A Airport Transfer Ltd | Transport & logistics | 2024 |