| Kaymin Properties UK Limited | Real estate | 2025 |
| KBA IT Limited | Information & communication | 2023 |
| Kelliher Construction Ltd | Construction | 2019 |
| Kellsafe Ltd | Professional & scientific | 2016 |
| Kendrick Enterprise UK Ltd | Wholesale & retail | 2008 |
| KM2WD Limited | Professional & scientific | 2006 |
| KOG Tech Ltd | Information & communication | 2018 |
| KP Humphries Ltd | Information & communication | 2016 |
| L&K Property Rental Limited | Real estate | 2024 |
| LA Bobina Ltd | Hospitality | 2015 |
| Labour Specialists Limited | Construction | 2017 |
| Lainey Hellings Aesthetics Ltd | Health & social care | 2025 |
| Lamoateng Limited | Health & social care | 2021 |
| LAN Nails & Spa Ltd | Other services | 2018 |
| Langdale Hall Limited | Hospitality | 2018 |
| Lansdowne Chemicals Limited | Manufacturing | 2017 |
| Laughlan GAS Services Ltd | Other services | 2018 |
| Leadbeater Management Limited | Professional & scientific | 2026 |
| Leap Forward Training Ltd | Professional & scientific | 2020 |
| Leaplets Ltd | Real estate | 2023 |
| Liam Barnes Building Ltd | Construction | 2022 |
| Lime Green Partnership Ltd | Administrative & support | 2011 |
| Limestone Law Limited | Professional & scientific | 2023 |
| Limestone Legal Consulting Ltd | Professional & scientific | 2025 |
| Lin-Jay Contracting Services Ltd. | Manufacturing | 2018 |
| Lincoln Lake Limited | Agriculture & fishing | 2018 |
| Lisa FOX Consulting Limited | Professional & scientific | 2026 |
| Little Fern's Limited | Hospitality | 2025 |
| Little Giants Nursery (Carterton) Limited | Health & social care | 2021 |
| Livey's Limited | Transport & logistics | 2011 |
| LMS Africa Limited | Information & communication | 2016 |
| Logic Trans Limited | Transport & logistics | 2013 |
| Lomo Properties Limited | Real estate | 2019 |
| London Health Concierge Ltd | Other services | 2019 |
| Longman Property Partners Ltd | Real estate | 2026 |
| Love Cottages Ltd | Hospitality | 2015 |
| LPW Vaporium Limited | Wholesale & retail | 2017 |
| LSC Corporate Limited | Professional & scientific | 2026 |
| LSC Trading Limited | Hospitality | 2026 |
| Lydon Ventures Ltd | Information & communication | 2025 |
| M a Smith ALL Screeds Ltd | Construction | 2008 |
| Manama Supermarket Ltd | Wholesale & retail | 2024 |
| Manicangel Ltd | Extraterritorial | 2022 |
| Manning Design Works Ltd | Professional & scientific | 2025 |
| Manor Road Management (Carterton) Limited | Administrative & support | 2014 |
| Mark Tickner FLY Fishing Limited | Real estate | 2018 |
| Marula Global Ltd | Mining & quarrying | 2012 |
| Marzing Consulting Limited | Financial services | 2009 |
| Mason Bentley Consulting Limited | Information & communication | 2018 |
| Matt's Garden & Grounds Ltd | Administrative & support | 2024 |
| Matwest (UK) Ltd | Manufacturing | 2007 |
| Maximillian Group Ltd | Construction | 2019 |
| MCD Analytics Limited | Professional & scientific | 2022 |
| Mcnally Bowles Ltd | Administrative & support | 2016 |
| Mcss Property Limited | Construction | 2018 |
| MDK Contracts Ltd | Financial services | 2019 |
| Meaningful Therapy Ltd | Health & social care | 2021 |
| Menial Ltd | Information & communication | 2009 |
| Mesopotamia Accountancy Limited | Extraterritorial | 2017 |
| Metiscc Holding Limited | Administrative & support | 2024 |
| Mhie Consulting Ltd | Information & communication | 2019 |
| Mian Channu PVT Ltd | Wholesale & retail | 2021 |
| Michael Flavell Limited | Administrative & support | 2026 |
| Middleton Transport Limited | Transport & logistics | 2019 |
| Millrick Construction Limited | Construction | 2026 |
| Mint Bowling Ltd | Arts & recreation | 2021 |
| MJH Promotions Limited | Arts & recreation | 2023 |
| Mjmenergy Limited | Professional & scientific | 1997 |
| MJP Squared Limited | Professional & scientific | 2020 |
| MN Decorators Limited | Construction | 2010 |
| Monarch Fire (UK) Limited | Other services | 2002 |
| MS Mechanical Ltd | Wholesale & retail | 2022 |
| Muddy Mule Limited | Agriculture & fishing | 2018 |
| MZO Holdings Ltd | Financial services | 2025 |
| N LEE & SON Ltd | Construction | 2017 |
| NEA Care Ltd | Health & social care | 2020 |
| Nehar Cuisine Limited | Hospitality | 2024 |
| New AGE Electrical Oxford Limited | Energy | 2017 |
| Newbury Marble Limited | Construction | 2017 |
| Newcroft Gardens Management Company Limited | Households | 2004 |
| Next Way Properties Ltd | Real estate | 2025 |
| Nextgen Beacon Ltd | Health & social care | 2025 |
| Nexus Venture Properties Ltd | Real estate | 2024 |
| Nicola Gardiner Executive Search Limited | Administrative & support | 2014 |
| NNJ Elite Kickboxing Ltd | Arts & recreation | 2025 |
| NO Key Storage Ltd | Administrative & support | 2024 |
| NO.1 Sweet Spot Ltd | Wholesale & retail | 2024 |
| Novusmet Ltd | Administrative & support | 2018 |
| NRN Services Ltd | Administrative & support | 2016 |
| Oak Habitat Ltd | Manufacturing | 2023 |
| Oakey Automotive Services Limited | Wholesale & retail | 2002 |
| Ocean Vortex Ltd | Transport & logistics | 2024 |
| ON Board Window Cleaners Limited | Administrative & support | 2017 |
| Onstage Accounts Ltd | Professional & scientific | 2026 |
| Optimum Removals Limited | Transport & logistics | 2017 |
| Oqema London Limited | Wholesale & retail | 2018 |
| Orangeville Investments Limited | Health & social care | 2025 |
| Osborne and Mann Limited | Construction | 2024 |
| OX Renovate Ltd | Construction | 2015 |
| Oxbotics Ltd | Information & communication | 2014 |