| Lboro FAN TV Ltd | Information & communication | 2023 |
| LEE Player Property Limited | Real estate | 2019 |
| LEE360 Ltd | Information & communication | 2025 |
| Legal Services Executors Ltd | Professional & scientific | 2024 |
| Legal Services Group Ltd | Professional & scientific | 2023 |
| Leith Henderson Limited | Construction | 2024 |
| Lets Escape Holdings Limited | Financial services | 2015 |
| Lets Escape Limited | Hospitality | 2020 |
| Levata Streetwear LP | | 2023 |
| Lifetime Legal & Financial Services Ltd | Professional & scientific | 2021 |
| Likks Limited | Hospitality | 2003 |
| Limekiln Mells Ltd | Administrative & support | 1990 |
| Linguae Recta Consulting (LRC) Ltd | Professional & scientific | 2021 |
| Link Retail Group Ltd | Wholesale & retail | 2026 |
| Liontek Land Holdings Ltd | Wholesale & retail | 2017 |
| Little Mouse Productions Limited | Information & communication | 2003 |
| Lived IT C.I.C. | Education | 2025 |
| Living Wholeness Ltd | Health & social care | 2006 |
| LM Autocare Limited | Wholesale & retail | 2019 |
| Lochnagar Limited | Information & communication | 2020 |
| London Wine Investors 2 LP | | 2011 |
| Long Hollow Cycles Ltd | Wholesale & retail | 2019 |
| Lucasandsons Ltd | Construction | 2019 |
| Lucky Trucking Ltd | Transport & logistics | 2019 |
| Luminelle Health Limited | Health & social care | 2026 |
| LUX Investments Ltd | Real estate | 2022 |
| LUX Spaces Ltd | Construction | 2021 |
| LWP Property Ltd | Construction | 2022 |
| M & H Hair Limited | Other services | 2011 |
| M & N Transport (Wilts) Limited | Transport & logistics | 2002 |
| M J Building (South West) Ltd | Construction | 2016 |
| M Pieters Wealth Management Ltd | Financial services | 2023 |
| M-Tech Automotive Limited | Manufacturing | 2025 |
| M-Tech MOT Centre Limited | Wholesale & retail | 2010 |
| M2DCON UK Limited | Public administration | 2024 |
| Macadams Books Limited | Arts & recreation | 2015 |
| Magic Seeder Europe Limited | Manufacturing | 2006 |
| Maid by Design Ltd | Administrative & support | 2024 |
| Maid Technology Limited | Information & communication | 1998 |
| Main Quest Ltd | Professional & scientific | 2026 |
| Maltings (Westbury) Management Company Limited(The) | Households | 1985 |
| Mamba Designs Ltd | Manufacturing | 2021 |
| Mammoth Fitness LP | | 2021 |
| Managing the Green Planet CIC | Professional & scientific | 2025 |
| Manley Engineering Ltd | Extraterritorial | 2006 |
| Mark a Whittington Limited | Construction | 2023 |
| Mark Bryant Ltd | Transport & logistics | 2026 |
| Markson Homes Limited | Real estate | 2022 |
| Marlborough Court (Westbury) Management Company Limited | Households | 2008 |
| Marlborough House Advisors Ltd | Administrative & support | 2025 |
| Marshfield Capital Ltd | Financial services | 2023 |
| Martin Mcgillick Ltd | Hospitality | 2019 |
| Martin Osborne Ltd | Manufacturing | 2010 |
| Martinique Way NO.2 Limited | Real estate | 2023 |
| Martinique Way Village Limited | Construction | 2023 |
| Martyn Brown GAS Appliance Services Ltd | Construction | 2015 |
| Mathematx Ltd | Wholesale & retail | 2025 |
| Mathilda Investments | Professional & scientific | 2025 |
| Matt Hurley TRS Limited | Manufacturing | 2009 |
| Maysama Ltd | Manufacturing | 2019 |
| Mcevilly Properties Limited | Real estate | 2021 |
| MDC Electrical Installations Ltd | Construction | 2014 |
| Meadows Classic Restoration Limited | Wholesale & retail | 2016 |
| Meads Abodes Ltd | Households | 2024 |
| Meals on Wheels Frome Ltd | Hospitality | 2022 |
| Mediprompt Healthcare Limited | Wholesale & retail | 2023 |
| Melrohart Limited | | 1985 |
| Mendip Forestry Limited | Agriculture & fishing | 1984 |
| Merlin House (Westbury) Management Company Limited | Households | 1983 |
| MGE Automation Limited | Administrative & support | 2008 |
| Michael Elkins Limited | Wholesale & retail | 1972 |
| Migdol-Oz Ltd | Manufacturing | 2026 |
| Mike Brooks Creative Ltd | Arts & recreation | 2025 |
| Mill Management Services Limited | | 1991 |
| Millbrook Aesthetics and Prescribing Ltd | Health & social care | 2022 |
| Millenium Management Limited | Other services | 1998 |
| Millers Homestores Limited | Wholesale & retail | 2000 |
| Milton Terrace Management Company Limited | Real estate | 2004 |
| Mindset Training Limited | Information & communication | 2011 |
| Mirado Computing Limited | Information & communication | 1999 |
| MIZ Street Food Ltd | Hospitality | 2023 |
| MJ Bartlett Building LLP | | 2020 |
| MJB Sales & Distribution Ltd | Wholesale & retail | 2024 |
| MK Establishments Ltd | Construction | 2025 |
| Mobility Works Limited | Wholesale & retail | 2007 |
| Modula X Ltd | Manufacturing | 2018 |
| Montague Motors Limited | Wholesale & retail | 2014 |
| Moomo Limited | Manufacturing | 2016 |
| Moonraker Beds Limited | Manufacturing | 2003 |
| More Bushes Limited | Administrative & support | 2016 |
| MOT Check Mate Ltd | Wholesale & retail | 2026 |
| Motivate 360 Home Care Ltd | Health & social care | 2025 |
| Motor Accessories Ltd | Construction | 2020 |
| Motorsport Electronics Limited | Manufacturing | 2014 |
| MS Cosmetic Car Care Ltd | Wholesale & retail | 2021 |
| MS P&H Ltd | Construction | 2023 |
| MUD Creative Ltd | Arts & recreation | 2013 |
| Muddy Dog Events Limited | Arts & recreation | 2017 |
| Mudie-Bond Limited | Extraterritorial | 1987 |
| My Accountant Online Limited | Professional & scientific | 2010 |