| Loach Fire Safety Limited | Professional & scientific | 2020 |
| Lockside Developments Ltd | Construction | 2018 |
| Locstar Limited | Transport & logistics | 2008 |
| Lodrix Ltd | Construction | 2024 |
| London Clean Air Limited | Extraterritorial | 2024 |
| London Hockey Limited | Arts & recreation | 2021 |
| Longridge on the Thames | Arts & recreation | 2007 |
| Longwood Mews Management Company Limited | Households | 2012 |
| Lotus Landscapes Ltd | Professional & scientific | 2025 |
| Lovesupplementsuk Ltd | Wholesale & retail | 2023 |
| Loveswim Ltd | Arts & recreation | 2025 |
| Lower Cookham Road (Maidenhead) Management Company Limited | Households | 2002 |
| Lower House Management (GX) Limited | Households | 2022 |
| LRB Consulting & Training Limited | Professional & scientific | 2018 |
| LRP Consultancy Ltd. | Health & social care | 2015 |
| Lucy Kennedy Limited | Professional & scientific | 2021 |
| Ludlow Road (Maidenhead) Management Company Limited | Households | 1991 |
| Ludlow Road (Maidenhead) Management RTM Company Limited | Households | 2010 |
| Lumari Drinks Ltd | Manufacturing | 2026 |
| Lumatech Limited | Wholesale & retail | 2007 |
| Lundy Pharma Consulting Ltd | Professional & scientific | 2023 |
| Lush Catering Limited | Hospitality | 2025 |
| Luso International Fencing Ltd | Education | 2020 |
| Luul Limited | Education | 2022 |
| Luurts in Motion Limited | Professional & scientific | 2017 |
| Luxury by Leonora Ltd | Wholesale & retail | 2024 |
| Luxury Outdoor Limited | Wholesale & retail | 2023 |
| LWR Developments Limited | Construction | 2003 |
| LWR Developments Property Ltd | Real estate | 2019 |
| LWS Academy Limited | Health & social care | 2025 |
| Lynch Cooper Limited | Construction | 2012 |
| M & D Comprop Limited | Hospitality | 2006 |
| M a S S Property Limited | Real estate | 2005 |
| M B S Security & Facilities Management Ltd | Administrative & support | 2020 |
| M B Turf Limited | Administrative & support | 2023 |
| M H P Industries Limited | Manufacturing | 1998 |
| M J Edwards Builders' Merchant Limited | Professional & scientific | 2001 |
| M Stothers Legacy Investment Company Limited | Financial services | 2025 |
| M&E Advisory Ltd | Professional & scientific | 2025 |
| M.A.B. Electrical Services Limited | Construction | 2013 |
| M.Barrett Creative Ltd. | Arts & recreation | 2022 |
| M.E. Hamilton Limited | Manufacturing | 1999 |
| M.H. Estates Ltd. | Construction | 1996 |
| M3 Marketing Ltd | Administrative & support | 2020 |
| M62 Connect Limited | Real estate | 2022 |
| MAC 3 Limited | Hospitality | 2025 |
| Mackintosh Court Management Company Limited | Households | 2007 |
| Macleod and Partners Limited | Professional & scientific | 2015 |
| Made of Mischief Limited | Professional & scientific | 2024 |
| Madelec LED UK Limited | Manufacturing | 2019 |
| Magenta Projects Limited | Construction | 2010 |
| Maiden Vale (Craufurd Rise) Limited | Households | 2020 |
| Maidenhead Chamber (Trading) Ltd | Hospitality | 2024 |
| Mama BEE Group | Education | 2017 |
| Mamajoo UK Limited | Wholesale & retail | 2018 |
| Manage Health Ltd | Financial services | 2008 |
| Mancha Productions Ltd | Information & communication | 2010 |
| Manna Investments Limited | Real estate | 2018 |
| Manor Court (Slough) Management Company Limited | Households | 1997 |
| Manor Court RTM Company Limited | Households | 2018 |
| Maple (196) Limited | Households | 2003 |
| Marching on Limited | Professional & scientific | 2016 |
| Mares Diem Ltd | Administrative & support | 2025 |
| Margaret Court (High Wycombe) Residents Association Limited | Households | 1982 |
| Margi Rose Consultancy Limited | Administrative & support | 2012 |
| Marigold Enterprises Private Limited | Hospitality | 2024 |
| Marina Sound Ltd | Information & communication | 2025 |
| Market Square (Chesham) Management Company Limited | Households | 2015 |
| Marlow Aesthetics Ltd | Other services | 2026 |
| Marlow and District Schools' Boathouse Trust | Arts & recreation | 2013 |
| Marlow Bottom Fryers Limited | Hospitality | 2009 |
| Marlow Bridge Limited | Wholesale & retail | 1998 |
| Marlow Car Club Limited | Administrative & support | 2025 |
| Marlow Car Wash Limited | Administrative & support | 2018 |
| Marlow Commercial Property Management Services Ltd | Real estate | 2010 |
| Marlow Construction & Surveying Ltd | Professional & scientific | 2020 |
| Marlow Consultants Ltd. | Information & communication | 1993 |
| Marlow Consulting Group Ltd | Professional & scientific | 2024 |
| Marlow Counselling Ltd | Health & social care | 2026 |
| Marlow Cycles Ltd | Manufacturing | 2020 |
| Marlow Design and Build Limited | Construction | 2023 |
| Marlow Dough Ltd | Hospitality | 2025 |
| Marlow Education Trust | Education | 2011 |
| Marlow Executive Cars Ltd | Transport & logistics | 2018 |
| Marlow Face and Body Limited | Other services | 2019 |
| Marlow FC Juniors Ltd | Education | 2021 |
| Marlow Five-O Limited | Wholesale & retail | 2018 |
| Marlow Football Club Limited | Arts & recreation | 1998 |
| Marlow Green Limited | Wholesale & retail | 2019 |
| Marlow Group Limited | Real estate | 2023 |
| Marlow House Group Ltd | Information & communication | 2019 |
| Marlow Inns Limited | Real estate | 1993 |
| Marlow Labs Limited | Information & communication | 2025 |
| Marlow Management Services Limited | Professional & scientific | 1995 |
| Marlow MBS Ltd | Health & social care | 2020 |
| Marlow Mentors Ltd | Education | 2025 |
| Marlow Mill Residents Association Limited | Real estate | 1982 |
| Marlow Mobile VET Limited | Professional & scientific | 2025 |
| Marlow Mortgage Co Ltd | Financial services | 2022 |
| Marlow Payroll Service Limited | Professional & scientific | 2025 |