| KP Consortium Ltd | Health & social care | 2016 |
| KR Holdings Ltd. | Construction | 2018 |
| Krinvest Care Group Ltd. | Health & social care | 2010 |
| Krinvest Limited | Education | 2000 |
| KT Deptford Ltd | Construction | 2025 |
| KT Frame Development Limited | Construction | 2021 |
| KT PO5 Ltd | Construction | 2025 |
| Kufi & Co Limited | Information & communication | 1997 |
| Kupsdelight Ltd | Hospitality | 2016 |
| Kutsal Ltd | Construction | 2024 |
| Kyndral Ltd | Wholesale & retail | 2025 |
| Langley Wood Freehold Limited | Households | 2022 |
| Lateral Fire & Security Ltd | Construction | 2021 |
| Lateral Plumbing and Heating Services Ltd | Construction | 2023 |
| Laurel Prop Investments Ltd | Real estate | 2026 |
| Lawford Construction Ltd | Construction | 2020 |
| Lawford Gardens Maintenance Company Limited | Administrative & support | 1985 |
| Lawrence Webster Forrest Limited | Professional & scientific | 1987 |
| Lawry Paving & Landscaping Limited | Administrative & support | 2022 |
| Laxmi Assets Ltd | Real estate | 2018 |
| Laxmiram Holdings Limited | Real estate | 2024 |
| Laxmiram Investments Limited | Real estate | 2020 |
| LE Reve Building and Property Developments Limited | Construction | 2010 |
| Leadale Contractor Solutions Limited | Professional & scientific | 2016 |
| Learning Presenters LLP | | 2025 |
| LEE Antony Smith Ltd | Extraterritorial | 2022 |
| LF Ventures Limited | Education | 2025 |
| Limes Investments Limited | Financial services | 2024 |
| Limes Studios Limited | Real estate | 2009 |
| Little Heaton Care Limited | Health & social care | 2005 |
| LM01 Ltd | Real estate | 2022 |
| Lobster Beach Limited | Wholesale & retail | 2011 |
| Loma Recruitment Ltd | Administrative & support | 2022 |
| Lonbridge Consulting Ltd | Information & communication | 2024 |
| London Business Network Limited | Professional & scientific | 2013 |
| London Craftsmen Centre Ltd | Manufacturing | 2009 |
| London Craftsmen Investments Ltd | Professional & scientific | 2017 |
| London Curtain Makers Limited | Manufacturing | 2010 |
| London Fabric Company Limited | Wholesale & retail | 2009 |
| London Fabric Walling Limited | Manufacturing | 2010 |
| London Upholsterers Limited | Other services | 2009 |
| Lorna Brash Food Stylist Ltd | Hospitality | 2013 |
| Lovegrass Limited | Wholesale & retail | 2015 |
| Lovista Limited | Wholesale & retail | 2025 |
| Lowe Associates Limited | Professional & scientific | 2018 |
| Lowe Finance Limited | Professional & scientific | 2014 |
| LPM Consultancy Service Limited | Administrative & support | 2012 |
| Lugonvu Limited | Public administration | 2022 |
| Lupin Financial Services Limited | Financial services | 2024 |
| Luxe Lounge HQ Ltd | Other services | 2022 |
| M & U (UK) Limited | Wholesale & retail | 2005 |
| M&M Moran Ltd | Construction | 2003 |
| Mabelhall Limited | Professional & scientific | 2022 |
| Made by Humans Ltd | Hospitality | 2008 |
| MAJ Travel Services Limited | Other services | 2022 |
| Majestic Lifts Ltd | Professional & scientific | 2023 |
| Maliss Limited | Financial services | 2024 |
| Mamajanes Limited | Hospitality | 2024 |
| Maple House Rehab Ltd. | Health & social care | 2016 |
| Marbletown Limited | Real estate | 1985 |
| Marcel - Multimedia Art Research Centres and Electronic Laboratories | Education | 2003 |
| Masala and Misfits Ltd | Hospitality | 2025 |
| Masha Parekh Estates Limited | Real estate | 2025 |
| Master Solar Energy Ltd | Wholesale & retail | 2024 |
| Maude Group Ltd | Professional & scientific | 2026 |
| MB Prosperity Investments Limited | Real estate | 2021 |
| Medicaid Healthcare Solutions Ltd | Administrative & support | 2022 |
| Medpub Consulting Ltd | Information & communication | 2024 |
| Mercury Lifecare Limited | Health & social care | 2021 |
| MGP Consulting Ltd | Professional & scientific | 2026 |
| Mireille Favour Limited | Other services | 2022 |
| MM Lower RD RTM Company Limited | Households | 2024 |
| MNZ Limited | Real estate | 2013 |
| Mount Pleasant Solutions Limited | Real estate | 2017 |
| Mountsfield Gardens (NO 1) Management Limited | Households | 1997 |
| Mpnd Grooming Limited | Other services | 2019 |
| Mprsd Ltd | Arts & recreation | 2023 |
| MR Charlie's UK Holdings Limited | Hospitality | 2026 |
| MRM Property Management Ltd | Real estate | 2024 |
| Mummy Made Enterprises Limited | Hospitality | 2025 |
| Murfitt Consulting Limited | Professional & scientific | 2008 |
| Musbal Ltd | Wholesale & retail | 2022 |
| N Armstrong Properties Limited | Real estate | 2024 |
| N L Armstrong Limited | Real estate | 2019 |
| NAC Enterprises Ltd | Information & communication | 2009 |
| Naca Investment Ltd | Real estate | 2020 |
| Nashthelle Limited | Professional & scientific | 2025 |
| Neathelp Ltd | Administrative & support | 2019 |
| Nelson Tree Care Limited | Administrative & support | 2014 |
| Nelson Tree Commercial Limited | Administrative & support | 2024 |
| Neolaia Limited | Other services | 2024 |
| Neonology Limited | Wholesale & retail | 2014 |
| Nest Native Group Ltd | Professional & scientific | 2023 |
| New Causeway Management Company Limited | Households | 2005 |
| Newways Care Ltd | Health & social care | 2025 |
| Nick Clements Consulting Limited | Wholesale & retail | 2012 |
| Niwasa Property Solutions Ltd | Construction | 2025 |
| NK Creative Associates Limited | Wholesale & retail | 2024 |
| NMG Solutions Ltd | Construction | 2018 |
| NMS2P Ltd | Extraterritorial | 2022 |