| Land Major Limited | Professional & scientific | 1993 |
| Landrox 4X4 Limited | Wholesale & retail | 2004 |
| Laser Lines Limited | Wholesale & retail | 2004 |
| Lasergaming and High Ropes Ltd | Arts & recreation | 2022 |
| Lawncare Garden Machinery Limited | Manufacturing | 2006 |
| LE Papillon Vert Ltd | Wholesale & retail | 2010 |
| Legacy Build & Design Ltd | Construction | 2025 |
| Lemarc Distributors Limited | | 1981 |
| Leverpost Limited | Transport & logistics | 1963 |
| Licensed Intergrated Fire and Electrical Systems Limited | Extraterritorial | 2006 |
| Light Vessel Automatic Limited | Professional & scientific | 2004 |
| Limiteds Limited | Extraterritorial | 2006 |
| Linear Fisheries (Oxford) Limited | Agriculture & fishing | 1993 |
| Liquid Networks Ltd | Professional & scientific | 2011 |
| Little House Music Limited | Arts & recreation | 2000 |
| Livewires Automation Ltd | Information & communication | 1999 |
| Lock & Heat Retreat Ltd | Administrative & support | 2025 |
| Loft Digital Limited | Information & communication | 2007 |
| Loggia Investments Limited | Real estate | 2001 |
| Logisnext Leasing UK Limited | Financial services | 1997 |
| Logisnext UK Limited | Manufacturing | 1969 |
| London & Zurich Limited | Financial services | 1996 |
| London and Zurich Finance Limited | Financial services | 1989 |
| London Corn Investments Limited | Professional & scientific | 2004 |
| London Ethnic Skin Limited | Health & social care | 2012 |
| London Road Chiropody Clinic Limited | Health & social care | 2003 |
| Longwall Ventures 4 ECF (FP) LLP | | 2026 |
| Longwall Ventures 4 ECF (GP) LLP | | 2026 |
| Longwall Ventures 4 ECF (GP) Member Limited | Financial services | 2026 |
| Lovat Seven Holdings Limited | Administrative & support | 2020 |
| Lovat Seven Limited | Arts & recreation | 2018 |
| Lovat Seven Ventures Limited | Financial services | 2025 |
| Love Management Limited | Information & communication | 2011 |
| LPM Residential Ltd | Real estate | 2021 |
| Ludger Limited | Professional & scientific | 1999 |
| Lvd(Uk) Limited | Manufacturing | 1982 |
| Lyneham Farm Cottages Management Company Limited | Households | 1997 |
| M Tech Logistics Limited | Transport & logistics | 2001 |
| M&M Commercials (Abingdon) Limited | Wholesale & retail | 2005 |
| M. & M. Skip Hire Limited | Water & waste | 1992 |
| M.A.D. Training Limited | Education | 2003 |
| M.R. Deeley & Sons | | 1999 |
| Machining Technology (Mach-Tech) Ltd | Professional & scientific | 1998 |
| Magenta Communications Limited | Professional & scientific | 2004 |
| Magenta Films Limited | Information & communication | 2009 |
| Maincross Limited | Information & communication | 2000 |
| Mallison Inc. Limited | Professional & scientific | 2025 |
| Manon Dolphin Limited | Professional & scientific | 1999 |
| Margaret L.Johnson Limited | Wholesale & retail | 1962 |
| Mark-Making Limited | Professional & scientific | 2007 |
| Marlow Leisure Limited | Real estate | 2003 |
| Marshall's Industrial Limited | Wholesale & retail | 1995 |
| Mass E Solutions Limited | Information & communication | 2000 |
| Maxipos Corporation Ltd | Administrative & support | 2012 |
| Mayday Employment Limited | Administrative & support | 1997 |
| Mccabe - Construction Limited | Construction | 2016 |
| Mccabe Developments Limited | Real estate | 2021 |
| Mccdesign Ltd | Arts & recreation | 1999 |
| Mcgregor Advisory Limited | Professional & scientific | 2026 |
| Meech International Limited | Professional & scientific | 1956 |
| Meech SCT Limited | Professional & scientific | 1997 |
| Melt Liquidity Limited | Financial services | 2024 |
| Merchant Baker UK Limited | Wholesale & retail | 2002 |
| MH (Oxford) Limited | Professional & scientific | 2003 |
| MHP Services Limited | Hospitality | 1999 |
| Michael Boon Ltd | Other services | 2003 |
| Michael Lynes Jeweller Limited | Wholesale & retail | 1987 |
| MID Engineering Limited | Wholesale & retail | 2015 |
| Mightywaters Consulting Limited | Professional & scientific | 1998 |
| Mike & Mark Chainey Limited | Construction | 2005 |
| Mikrotek Solutions Ltd. | Wholesale & retail | 1996 |
| Mindful Action Coaching Ltd. | Professional & scientific | 2002 |
| Miseray Ltd | Wholesale & retail | 2016 |
| Misio Digital Ltd | Professional & scientific | 2019 |
| Mjlm Limited | Wholesale & retail | 2002 |
| MLC Parking Ltd | Administrative & support | 2003 |
| MLU Beauty Limited | Administrative & support | 2023 |
| MMR Research Worldwide Limited | Information & communication | 2001 |
| Modeltech Design Limited | Professional & scientific | 1999 |
| Modular Building Consultants Limited | Construction | 2011 |
| Molls Yard Limited | Real estate | 2020 |
| Momentum Bidco Limited | Financial services | 2025 |
| Momentum Topco Limited | Financial services | 2025 |
| Mondaytofriday Limited | Hospitality | 1999 |
| Monk Communications Limited | Professional & scientific | 2003 |
| Montagu Bond (Digital Services) Limited | Information & communication | 2020 |
| Montagu Bond Limited | Other services | 2019 |
| Moreton Consultancy Ltd | Professional & scientific | 2007 |
| Morfield Floating Hotels Ltd | Hospitality | 2023 |
| Moving Paradigms Limited | Professional & scientific | 2003 |
| Mr.R.G.And Mrs.A.M.Mathews | | 1990 |
| MTJ Media Ltd | Information & communication | 2007 |
| Muziris Capital Limited | Financial services | 2017 |
| My Own Coach Limited | Professional & scientific | 2004 |
| Mysongs Limited | Arts & recreation | 1973 |
| Nalas Baby Limited | Wholesale & retail | 2020 |
| Name Plate Holders Limited | Financial services | 2018 |
| Nanomagnetics Instruments Limited | Professional & scientific | 1998 |
| Nash's Bakeries Limited | Manufacturing | 2008 |
| Natasha Hurst Design Limited | Manufacturing | 2025 |