| Kiln Development Properties Ltd | Construction | 2018 |
| Kiln Holdings Ltd | Financial services | 2025 |
| Kiln Rental Properties Ltd | Real estate | 2025 |
| Kingston Management Services Limited | Professional & scientific | 2013 |
| Kldh Limited | Real estate | 2003 |
| Kopa Holdings Ltd | Real estate | 2025 |
| Kopa Scaffolding Limited | Construction | 2022 |
| KR Nursery’S Ltd | Education | 2024 |
| L & B PUB Company Ltd | Hospitality | 2017 |
| L&B Brewing Co. Ltd | Hospitality | 2020 |
| L&B Renovations Ltd | Construction | 2021 |
| L&B Restaurant Group Ltd | Hospitality | 2019 |
| Landsand Ltd | Construction | 2021 |
| Laser Cleanse Ltd | Administrative & support | 2025 |
| LE CAP Ltd | Hospitality | 2026 |
| LE Mans Capital Limited | Arts & recreation | 2013 |
| Leave Nineteen Ltd | Health & social care | 2022 |
| LEE a Walton Ltd | Professional & scientific | 2024 |
| Levicept Ltd | Professional & scientific | 2012 |
| Lexie Minter Ltd | Health & social care | 2023 |
| Liam's Caribbean Ltd | Hospitality | 2025 |
| Light Accountants Ltd | Professional & scientific | 2020 |
| Lightcn Consultancy Services Ltd | Professional & scientific | 2016 |
| Lightcn Global Services Ltd | Professional & scientific | 2013 |
| LIT Photographic Limited | Professional & scientific | 2016 |
| Little & Large Roofing Ltd | Construction | 2025 |
| Little Miracles Hair Limited | Other services | 2002 |
| Little Sister Productions Ltd | Arts & recreation | 2025 |
| Live Free Consulting Ltd | Professional & scientific | 2022 |
| Livingstone Care Solutions Limited | Health & social care | 2018 |
| Local Shop Club Ltd | Wholesale & retail | 2020 |
| Logical Antigen Ltd | Professional & scientific | 2025 |
| Logical Biological Ltd | Professional & scientific | 2019 |
| Lole Wellness Cafe Ltd | Hospitality | 2025 |
| Londonburg House Ltd | Construction | 2025 |
| Love Business Consultancy Limited | Extraterritorial | 2006 |
| Love Tails Ltd | Agriculture & fishing | 2025 |
| Lowtide Consulting and Creative Limited | Professional & scientific | 2022 |
| LSW Plumbing & Heating Ltd | Construction | 2024 |
| Luminiscence UK Limited | Arts & recreation | 2025 |
| Lunchbox LAB Ltd | Information & communication | 2025 |
| M K Catering (South East) Limited | Hospitality | 2017 |
| M.D.F. Database Solutions Ltd | Information & communication | 2000 |
| M.I.S. Motorsport Limited | Financial services | 2017 |
| Machere Ltd | Agriculture & fishing | 2020 |
| Magnar Group Limited | Construction | 2018 |
| Malcolm Waite Limited | Wholesale & retail | 1979 |
| Malibu Grains Limited | Manufacturing | 2002 |
| Manage With Impact Ltd | Professional & scientific | 2025 |
| Mandy Prince IFA Ltd | Real estate | 2014 |
| Manilla Road Flat Management Company Limited | Households | 1975 |
| Marc Mortiboys Products Ltd | Wholesale & retail | 2025 |
| Marc Mortiboys Publishing Ltd | Information & communication | 2025 |
| Marc One Security (Kent) Ltd | Administrative & support | 2023 |
| Marc One Security (Sussex) Ltd | Administrative & support | 2023 |
| Marc One Security Services Ltd | Administrative & support | 2023 |
| Marine Software Limited | Information & communication | 1991 |
| Market Place Trading Co Ltd | Hospitality | 2018 |
| Marshborough Developments Limited | Construction | 2022 |
| Marshborough Properties Limited | Construction | 1996 |
| Martin K Property Ltd | Real estate | 2019 |
| Matheus Engineering Ltd | Professional & scientific | 2024 |
| Matkirst Limited | Construction | 2007 |
| Mayflower Consultancy Services Limited | Professional & scientific | 2016 |
| Mayflower Electrical Contractors Limited | Wholesale & retail | 1999 |
| Maygorm House RTE Limited | Households | 2006 |
| Mcgarry Group Holdings Ltd | Financial services | 2025 |
| Mcgarry Property Holdings Ltd | Real estate | 2025 |
| Meanfish Ltd | Professional & scientific | 2002 |
| Media Woman Limited | Information & communication | 2013 |
| Meian 158 Limited | Professional & scientific | 2011 |
| Mesaroli UK Ltd | Transport & logistics | 2019 |
| Metraco Energy Limited | Professional & scientific | 2012 |
| Metric Build Group Limited | Professional & scientific | 2025 |
| MGM Carpets Limited | Real estate | 1999 |
| Milk Plus Goods Limited | Wholesale & retail | 2025 |
| Mill Point Management Limited | Households | 2004 |
| Millchris Developments Limited | Construction | 2012 |
| MIND75 Performance Ltd | Arts & recreation | 2025 |
| Minter ET AL Limited | Health & social care | 2020 |
| Minters Limited | Transport & logistics | 1981 |
| Miss KAY Seamstress Ltd | Manufacturing | 2016 |
| MKR Recovery Services Ltd | Wholesale & retail | 2016 |
| MLA Consult Limited | Manufacturing | 2024 |
| Monicam Ltd. | Construction | 2000 |
| Monkton Carpets and Sons Limited | Construction | 2025 |
| Morgan Jones Holdings Limited | Extraterritorial | 2021 |
| Mortimer's of Canterbury Limited | Wholesale & retail | 2003 |
| Mouchmouch Designs Limited | Professional & scientific | 2012 |
| Mount Bros.(Deal)Limited | Construction | 1958 |
| Move Forward Transport Ltd | Transport & logistics | 2018 |
| MPP Trustee Limited | Professional & scientific | 2010 |
| Mtor Ltd | Wholesale & retail | 2014 |
| Mulvany IT Limited | Information & communication | 2009 |
| Murphie Holdings Ltd | Real estate | 2024 |
| Muse Incense Ltd | Wholesale & retail | 2023 |
| Musk-Ed Ltd | Education | 2025 |
| My a I B Ltd | Manufacturing | 2021 |
| Mypt Limited | Arts & recreation | 2016 |
| Myquarterly Ltd | Professional & scientific | 2021 |