| Little Wings Big Dreams Ltd | Health & social care | 2020 |
| LJ Bros Ltd | Wholesale & retail | 2025 |
| LJD Mortgages Ltd | Financial services | 2024 |
| LKS Financial Consulting Limited | Professional & scientific | 2026 |
| LLT Rail Ltd | Construction | 2020 |
| LM Construction Design Ltd | Construction | 2026 |
| Lobo Solutions Limited | Administrative & support | 2013 |
| Locaerise Match Ltd | Education | 2024 |
| Logistic Support Service VB Ltd | Transport & logistics | 2024 |
| London Child and Family Wellness Ltd | Wholesale & retail | 2020 |
| London Fire Prevention Service Ltd | Public administration | 2024 |
| London Luxury City Apartments Limited | Hospitality | 2026 |
| London Prime Client Services Ltd | Other services | 2026 |
| London School of Business & Innovation Limited | Education | 2013 |
| Londonville Limited | Households | 2020 |
| Lotus NP Ltd | Wholesale & retail | 2022 |
| Lotus Vision (London) Limited | Education | 2021 |
| Love Flour LDN Ltd | Manufacturing | 2025 |
| Lower Limb Healthcare Limited | Health & social care | 2025 |
| LTB Ventures Limited | Professional & scientific | 2014 |
| Lucas Lets Limited | Real estate | 2017 |
| Lucky's Collective Ltd | Wholesale & retail | 2025 |
| Lujainco Ltd | Manufacturing | 2025 |
| Lulu Hair and Beauty Limited | Other services | 2019 |
| Lulux Construction Limited | Construction | 2024 |
| Lumdoedge Ltd | Wholesale & retail | 2026 |
| Lumora Recruitment Ltd | Administrative & support | 2026 |
| Luneel Ltd | Wholesale & retail | 2024 |
| Lungta Oishi Limited | Wholesale & retail | 2021 |
| Lunivha Consultants Ltd | Professional & scientific | 2012 |
| Lunivo Property Ltd | Hospitality | 2026 |
| Lusa Home Ltd | Wholesale & retail | 2026 |
| Lusso Luxury Ltd | Other services | 2025 |
| LUX Logistics Limited | Transport & logistics | 2026 |
| Luxedge Boutique Ltd | Wholesale & retail | 2025 |
| LY (London) Ltd | Other services | 2021 |
| Lyfe Tech Ltd | Information & communication | 2025 |
| Lykan Entertainment Ltd | Arts & recreation | 2025 |
| M and M Global Forwarding Limited | Transport & logistics | 2019 |
| M D Hirani Limited | Construction | 2018 |
| M Edwards Electrical Limited | Construction | 2016 |
| M J Barrett Draughting Limited | Professional & scientific | 2007 |
| M Katana Ltd | Professional & scientific | 2024 |
| M Pepa Ltd | Construction | 2023 |
| M R Builder Contractors Limited | Construction | 2019 |
| M&M Plumbing Services UK Ltd | Construction | 2015 |
| M&R Accounting Systems Limited | Information & communication | 2021 |
| M.E.D. Electrical Services Limited | Construction | 2018 |
| M2 Building Services Limited | Manufacturing | 2007 |
| Macaulay Scott LLP | | 2010 |
| Mackenzie Plumbing Limited | Construction | 2017 |
| Mackiavelli Limited | Information & communication | 2025 |
| Macks Grill Ltd | Hospitality | 2025 |
| Macro Associates Ltd | Professional & scientific | 2013 |
| Madam ORI Skincare Limited | Manufacturing | 2019 |
| Madcommerce Ltd | Wholesale & retail | 2025 |
| Madi Rizal Limited | Health & social care | 2025 |
| Magnares Homes LLP | | 2023 |
| Magnares Properties Ltd | Real estate | 2023 |
| Mahnur Curry House Ltd | Hospitality | 2019 |
| Mahogany Group Limited | Hospitality | 2019 |
| Maison Haute Ltd | Real estate | 2025 |
| Maji Treats UK Ltd | Wholesale & retail | 2026 |
| Majid Mohammed Distinguished Trade and Investment Ltd | Wholesale & retail | 2025 |
| Major Creative Media Group Ltd | Information & communication | 2025 |
| MAK Learning Limited | Health & social care | 2010 |
| Makemyidea Limited | Manufacturing | 2023 |
| Malfaelgin Project Management Limited | Information & communication | 2018 |
| Malthus Services Ltd | Construction | 2018 |
| MAM Health Care Limited | Health & social care | 2015 |
| Mamo Vending Ltd | Wholesale & retail | 2025 |
| Manakamana Traders Ltd | Wholesale & retail | 2018 |
| Manare Property Limited | Real estate | 2019 |
| Manifold Wisdom House Ministry Ltd | Other services | 2012 |
| Manly Yellow Ltd | Manufacturing | 2025 |
| Manna-Seh Childcare and Education Limited | Education | 2010 |
| Manoperty Investments Ltd | Real estate | 2021 |
| Mapel Limited | Administrative & support | 2021 |
| Maple Beacon Lettings Limited | Real estate | 2025 |
| Marice Childcare Ltd | Administrative & support | 2025 |
| Marin MD Ltd | Construction | 2018 |
| Marine & Gold Creations Ltd | Manufacturing | 2021 |
| Marinelle Iram Limited | Professional & scientific | 2025 |
| Market Monkey Ltd | Professional & scientific | 2023 |
| Market Point Limited | Wholesale & retail | 2021 |
| Markov&M Ltd | Construction | 2015 |
| Marlovasoft Limited | Information & communication | 2025 |
| Marnzies Electrical Contractors Limited | Administrative & support | 2006 |
| Marquis & Co Accountants Ltd | Professional & scientific | 2020 |
| Marycyp Transport Ltd | Transport & logistics | 2025 |
| Mashallah Traders Ltd | Wholesale & retail | 2020 |
| Masons Plastering Limited | Construction | 2008 |
| Mass Tints Welling Ltd | Manufacturing | 2022 |
| Master PAN UK Ltd | Wholesale & retail | 2025 |
| Matchallama Ltd | Wholesale & retail | 2025 |
| Mathers & Hirst Limited | Water & waste | 2007 |
| Matt Marsh Holdings Ltd | Financial services | 2025 |
| Mava Plus Limited | Real estate | 2024 |
| Mava Property Limited | Real estate | 2024 |
| MAX Access Group Ltd | Construction | 2026 |