| Littleport Developments LLP | | 2021 |
| LJ C4 Systems Ltd | Professional & scientific | 2012 |
| LK Adaptive Limited | Information & communication | 2025 |
| Local Building Supplies Ltd | Wholesale & retail | 2020 |
| Lochy & Co Limited | Construction | 2025 |
| Lock Roofing Contractors Ltd | Construction | 2020 |
| Lock Roofing Ltd | Construction | 2022 |
| Lockyer Developments Ltd | Construction | 2026 |
| Locus ME UK Ltd | Wholesale & retail | 2022 |
| Loft Life (Kent) Limited | Construction | 2025 |
| Lolly POP Events Limited | Wholesale & retail | 2013 |
| London & Kent Neuroradiology Limited | Health & social care | 2022 |
| London and Kent Surgical Practice Ltd | Health & social care | 2009 |
| London Life Properties Ltd | Hospitality | 2018 |
| Long Acre Homes South Limited | Real estate | 2020 |
| Long Life Fencing and Decking Limited | Construction | 2024 |
| Longbridge (Birmingham) Management Company Limited | Households | 2024 |
| Longcroft Associates Limited | Extraterritorial | 2012 |
| Longfield Residential Management Company Limited | Households | 2023 |
| Longtail Services Limited | Professional & scientific | 2024 |
| Lonkhurst Associates Limited | Administrative & support | 2012 |
| Loop L Ltd | Professional & scientific | 2023 |
| Lord Panda Group Ltd | Real estate | 2019 |
| Lordswood Motorist Centre Ltd | Wholesale & retail | 2016 |
| Lotus Online Counselling Ltd | Health & social care | 2021 |
| Loudon Way Limited | Health & social care | 2012 |
| Love Being Well Limited | Health & social care | 2016 |
| Lovelock IFA Ltd | Financial services | 2015 |
| Lpbeauty Ltd | Other services | 2025 |
| LSM DS Holdings Ltd | Administrative & support | 2022 |
| LSM Formwork Equipment Ltd | Administrative & support | 2021 |
| Lucas Kennedy Group Ltd | Administrative & support | 2019 |
| Lucas Kennedy Limited | Administrative & support | 2008 |
| Lufith Property Brothers Limited | Real estate | 2020 |
| Luka Facilities Ltd | Construction | 2019 |
| Luka Property Rentals Ltd | Real estate | 2020 |
| Luka Steel Limited | Manufacturing | 2013 |
| Lunduna Ltd | Wholesale & retail | 2025 |
| Luton & Kent Commercial Services LLP | | 2020 |
| Luxuria Vita Ltd | Information & communication | 2025 |
| Luxury and Performance Cars Ltd | Wholesale & retail | 2022 |
| LVR Management Limited | Professional & scientific | 2022 |
| LWO (Milford Gardens) Limited | Professional & scientific | 2018 |
| Lynne Robinson Psychology and Coaching Ltd | Health & social care | 2018 |
| Lynsey Nicol Limited | Information & communication | 2016 |
| Lyons Letting Ltd | Real estate | 2020 |
| M & L Residential Ltd | Real estate | 2025 |
| M a Hart Ltd | Financial services | 2012 |
| M G M Network Services Limited | Information & communication | 1989 |
| M G Tracey Limited | Information & communication | 2016 |
| M Group Construction Limited | Manufacturing | 2018 |
| M J & C Ltd | Transport & logistics | 2018 |
| M J Hinton Consultancy Limited | Administrative & support | 2012 |
| M Way World Ltd | Administrative & support | 2023 |
| M&A Railway Solutions Ltd | Administrative & support | 2019 |
| M.I.T. Publishing Limited | Information & communication | 1998 |
| M.K. Limited | Wholesale & retail | 1984 |
| M.N.R. Residents Management Company Limited | Real estate | 2004 |
| M80 Developments Ltd | Construction | 2006 |
| M80 Living Limited | Construction | 2023 |
| M80 Properties Ltd | Construction | 2018 |
| Macallen Roofing Services Limited | Construction | 2019 |
| Macdonald Fyne Ltd | Wholesale & retail | 2015 |
| Macmolly Ltd | Real estate | 2025 |
| Madetru Developments Ltd | Real estate | 2021 |
| Madetru Ltd | Construction | 2020 |
| Maestro Entertainment Limited | Arts & recreation | 2022 |
| Magnus Search Limited | Administrative & support | 2024 |
| Magrock Construction Limited | Extraterritorial | 2016 |
| Magrock Construction UK Limited | Extraterritorial | 2016 |
| Magrock Development Limited | Extraterritorial | 2016 |
| Magrock Facilities Management Limited | Administrative & support | 2017 |
| Magrock Group Limited | Financial services | 2017 |
| Magrock Limited | Construction | 2016 |
| Magrock Special Projects Limited | Extraterritorial | 2016 |
| Magrock UK Limited | Extraterritorial | 2016 |
| Maidstone Pallet Recycling Solutions Limited | Other services | 2024 |
| Mainland Power Ltd | Manufacturing | 2022 |
| MAINY10 Electrical Services Limited | Energy | 2017 |
| Malling Accountancy Limited | Professional & scientific | 2022 |
| Malling Consultants Limited | Professional & scientific | 2020 |
| Malling Court Management Company Limited | Households | 1999 |
| Malling Masonry LLP | | 2019 |
| Malling Place Residents Limited | Households | 2024 |
| Malling Properties Ltd | Real estate | 2022 |
| Maltings Place SE1 Limited | Real estate | 2016 |
| Managemi Software Limited | Information & communication | 2013 |
| Mandalay Holdings Ltd | Administrative & support | 2018 |
| Manpaweela & Bhavarjan Limited | Financial services | 2024 |
| Manta Thai Limited | Hospitality | 2024 |
| Maple Grange Management Company Limited | Households | 2025 |
| Margetts & Associates Limited | Professional & scientific | 2011 |
| Maria Marshall Photography Ltd | Professional & scientific | 2019 |
| Mark's Plumbing & Heating Contractors Limited | Construction | 2024 |
| Market Street (Bracknell) Management Company Limited | Households | 2026 |
| Marketwide Limited | Administrative & support | 2018 |
| Marshe Electrical Limited | Construction | 2012 |
| Martello Lakes (Vistry) Management Company Limited | Households | 2024 |
| Martin Rushworth Limited | Real estate | 2025 |
| Martin Wilde Jewellers Limited | Manufacturing | 2002 |