| Lightwood Offices Ltd | Real estate | 2020 |
| Lightwood Planning Limited | Professional & scientific | 2013 |
| Lightwood Strategic Braintree Ltd | Real estate | 2016 |
| Lightwood Strategic Limited | Real estate | 2012 |
| Lightwood Strategic Two Limited | Real estate | 2023 |
| Lightwood Wimbledon Limited | Real estate | 2017 |
| Lilyrock Limited | Professional & scientific | 2006 |
| Limaani Investment Ltd | Real estate | 2023 |
| Limaani Trading Ltd | Health & social care | 2021 |
| Limited Company Contractor Solutions Limited | Professional & scientific | 2010 |
| Limitless Technology Group Ltd | Information & communication | 2023 |
| Line UP Productions Limited | Financial services | 2012 |
| Link Team Limited | Transport & logistics | 2026 |
| Linton Telefield Ltd | Financial services | 2023 |
| Lisa Theobald Consulting Limited | Information & communication | 2023 |
| Lismacfinnin Limited | Professional & scientific | 2024 |
| Litigation Funding Consultancy Limited | Financial services | 2017 |
| Little Pine Trees Limited | Households | 2001 |
| Little Square Capital Limited | Financial services | 2020 |
| Littleworth Properties Limited | Construction | 1997 |
| Livecel Ltd | Information & communication | 2015 |
| LJ Sport Communications Ltd | Professional & scientific | 2018 |
| Ljud Solutions Limited | Administrative & support | 2022 |
| Llambias Associates Limited | Administrative & support | 2014 |
| Lloyd-Ortegon Property Investments Limited | Real estate | 2026 |
| LMH Consultancy Ltd | Professional & scientific | 2018 |
| Locationfinder Ltd | Information & communication | 2011 |
| Lochmore Investments Limited | Real estate | 2012 |
| Lochmore Property Management Ltd | Real estate | 2014 |
| Logan Cars Ltd | Transport & logistics | 2025 |
| Logic Evolution Limited | Information & communication | 2013 |
| Logie-Tech Ltd | Information & communication | 2026 |
| Lokonos Ltd | Information & communication | 2015 |
| Lomond Consulting Limited | Administrative & support | 1999 |
| London Asset Management Ltd | Construction | 2019 |
| London Calling Tours Limited | Administrative & support | 2024 |
| London Centre for Endocrinology & Diabetes Ltd | Health & social care | 2024 |
| London Irish Rugby Football Club Limited | Arts & recreation | 2020 |
| London Letterbox Limited | Transport & logistics | 2014 |
| London Opera Ensemble Ltd | Arts & recreation | 2026 |
| London Road (Laburnum Court) Residents Company Limited | Professional & scientific | 1972 |
| London Security Group Limited | Administrative & support | 2004 |
| Longcross Drapes Ltd | Manufacturing | 2025 |
| Longdown Capital Limited | Professional & scientific | 2016 |
| Loozey Loves Lates Limited | Arts & recreation | 2024 |
| Lost Souls Music Limited | Administrative & support | 2019 |
| Louise Duval Designs Ltd | Professional & scientific | 2023 |
| Lowenna Consulting Ltd | Professional & scientific | 2022 |
| LOZ Ltd | Transport & logistics | 2019 |
| LP Consulting International Ltd | Other services | 2025 |
| LP North Twenty SIX Limited | Wholesale & retail | 2023 |
| LSG (Yeoman) Limited | Administrative & support | 2013 |
| Lucy Ellis Ltd | Professional & scientific | 2024 |
| Ludgate Associates Limited | Hospitality | 1998 |
| Ludgate Northumberland Holdings Limited | Real estate | 2005 |
| Lulworth Pines Ltd | Administrative & support | 2025 |
| Lumi GLO Limited | Wholesale & retail | 2023 |
| Luscinio Limited | Real estate | 2024 |
| Luxescape Landscaping Ltd | Administrative & support | 2025 |
| Luxury ET AL Limited | Real estate | 2023 |
| Luxury Flooring Ltd | Construction | 2014 |
| LWP Freeholds Limited | Other services | 2013 |
| Lybrieth Limited | Administrative & support | 2010 |
| Lynden Gate Residents Limited | Households | 1983 |
| Lyrh Investment Limited | Financial services | 2020 |
| M & J Magee Limited | Administrative & support | 2006 |
| M Q Corporation Limited | Professional & scientific | 2015 |
| M&I Logistics Express Ltd | Transport & logistics | 2015 |
| M3 Truck & Van Sales Limited | Extraterritorial | 2022 |
| Machir Limited | Financial services | 2016 |
| Macrocosm Ltd | Professional & scientific | 2020 |
| MAD COW Apparel Limited | Wholesale & retail | 2026 |
| Maddy Nadin Ltd | Professional & scientific | 2021 |
| Made for Gamers Limited | Information & communication | 2021 |
| Major Property Ventures Ltd | Real estate | 2022 |
| Malaga Car Hire Limited | Professional & scientific | 1997 |
| Malarmahl Ltd | Professional & scientific | 2000 |
| Malik & Brothers Ltd | Transport & logistics | 2021 |
| Manage My Ltd | Information & communication | 2018 |
| Managemy Nominees Limited | Administrative & support | 2018 |
| Mancha Services Ltd | Other services | 2016 |
| Mandarin UK Limited | Manufacturing | 2007 |
| Manifold Trustee Company Limited (the) | Education | 1970 |
| Mannerco Limited | Extraterritorial | 1995 |
| Manreefer Limited | Transport & logistics | 2017 |
| Maplehurst Estates Ltd | Financial services | 2014 |
| Marble Hill Cafe Limited | Hospitality | 2006 |
| Marchwood Developments Limited | Real estate | 2016 |
| Maria Mansoor Ltd | Real estate | 2026 |
| Marine Elements Ltd | Professional & scientific | 2019 |
| Marine Parade One Ltd | Real estate | 2024 |
| Mariners ROW Capital | Financial services | 2017 |
| Market Mews SE1 Limited | Extraterritorial | 2008 |
| Marketing Mums Limited | Professional & scientific | 2022 |
| Marlborough Finance Limited | Manufacturing | 2017 |
| Marlow Court (Crawley) Residents' Association Limited | Households | 1962 |
| Marlowe Ventures Limited | Financial services | 2025 |
| Marlyn Lodge Management Company Limited | Real estate | 1983 |
| Marney's Pond Ltd | Hospitality | 2008 |
| Marrick Commercial Interiors Limited | Construction | 2008 |